CN119157223A

CN119157223A - Fresh corn food and preparation method thereof

Info

Publication number: CN119157223A
Application number: CN202411089419.9A
Authority: CN
Inventors: 刘会省; 孙挺; 王雪; 魏静; 孙建国; 张永久; 薛国典; 郭忠良; 刘立强; 张同宝; 陆思宇; 耿培忠; 冷友斌
Original assignee: Heilongjiang Beiwei 477 Green Organic Food Co ltd
Current assignee: Heilongjiang Beiwei 477 Green Organic Food Co ltd
Priority date: 2024-08-08
Filing date: 2024-08-08
Publication date: 2024-12-20

Abstract

The invention provides fresh corn food and a preparation method thereof, and belongs to the technical field of food processing. The preparation method of the fresh corn food comprises the steps of sequentially carrying out pretreatment, enzyme deactivation and post-treatment on materials to be processed to prepare the fresh corn food, wherein the enzyme deactivation step comprises the step of carrying out microwave enzyme deactivation on the materials to be deactivated in a microwave environment after covering flexible protection pieces with the materials to be deactivated. The preparation method provided by the invention can effectively improve the enzyme-inactivating effect of the fresh corn food, and simultaneously retain rich nutrient substances, so that the quality of the fresh corn food is obviously improved.

Description

Fresh corn food and its preparation method

Technical Field

The invention relates to the technical field of food processing, in particular to fresh corn food and a preparation method thereof.

Background

Fresh corn refers to corn ears or kernels harvested in the milk ripening period, also known as fresh corn. The fresh corn kernel milk can produce more sugar, starch, crude fat and various vitamins and amino acids in the ripening period, has better taste and nutritive value compared with the dry corn and the old corn, is more convenient to eat, and can be eaten only by boiling or steaming.

Conventional fresh corn foods generally comprise quick-frozen corn cobs, vacuum-packed corn cobs and quick-frozen corn kernels, and during the preparation process of the fresh corn foods, enzymes in the raw materials still keep activity after harvesting, and under proper temperature and condition, the enzymes accelerate physiological metabolism of corn, so that loss of nutrients and quality reduction are caused, and therefore, enzyme deactivation treatment is generally required for processing raw materials.

In the conventional art, enzyme deactivation treatment is often performed by means of hot water blanching, so that it is desired to inhibit or destroy the activity of these enzymes, thereby slowing or preventing the occurrence of the above-mentioned adverse changes.

However, in the prior art, hot water at 95 ℃ is generally adopted for blanching, when whole corn is blanched in the hot water, heat is conducted from water with higher temperature to corn kernels with lower temperature and then is conducted to the corn cob from the corn kernels, and because the diameter of the corn cob is larger and the structure is tighter, the heat is conducted to the corn cob through the corn kernels at a slower speed, so that even after the corn kernels of the whole corn are fully deactivated, more enzymes such as catalase exist in the corn cob, so that the enzyme deactivation effect of fresh corn foods is poorer and the quality is seriously reduced after long-time storage.

In addition, corn is directly contacted with high temperature water during blanching, so that water-soluble nutrients and pigment substances which are rich in the corn are dissolved in the high temperature water to be seriously lost (for example, the loss rate of soluble sugar content is about 38 percent and the VC loss rate is about 50 percent), and especially the loss rate of anthocyanin and other nutritional ingredients in color corn and black corn is particularly serious, so that the fresh corn food has lower nutritional value and poorer quality.

Disclosure of Invention

The invention solves the technical problems that:

In the prior art, in the process of preparing fresh corn food, hot water blanching is adopted for enzyme deactivation, so that the corncob of whole corn is incomplete in enzyme deactivation, the enzyme deactivation effect of the fresh corn food is poor, and corn is directly contacted with high temperature water during blanching, so that the rich nutrients and pigment substances of the corn are seriously lost, and therefore, a method for preparing the fresh corn food with good enzyme deactivation effect, high nutritive value and excellent quality is still needed.

Aiming at least one part of the defects, the invention provides a fresh corn food and a preparation method thereof, which can realize complete enzyme deactivation of whole corn ears and change the technological defects that corn needs to be directly contacted with high temperature water for blanching, thereby overcoming the problems of poor enzyme deactivation effect, serious nutrient loss, poor quality and the like of the fresh corn food.

The technical scheme of the invention is as follows:

1. a preparation method of fresh corn food comprises sequentially performing pretreatment, enzyme deactivation and post-treatment to the material to be processed to obtain fresh corn food;

the enzyme deactivation process comprises the step of carrying out microwave enzyme deactivation in a microwave environment after covering the flexible protection piece with a material to be deactivated.

2. The method for preparing a fresh corn food according to item 1, wherein the enzyme-inactivating step comprises:

And conveying the material to be deactivated in a microwave environment after covering the flexible protection piece, wherein the microwave deactivation is carried out for a first preset time, and the first preset time is 1-10 min, preferably 4-10 min.

3. The method for preparing fresh corn food according to item 2 or 3, wherein the step of inactivating the enzyme further comprises stopping microwave treatment of the microwave-inactivated material, and maintaining the temperature for a second predetermined time, preferably, the second predetermined time is 0.1-10 min.

4. The method for preparing a fresh corn food according to any one of items 1 to 3, wherein the flexible protective member comprises at least one of Teflon high temperature cloth, silicone cloth or polyester film.

5. The method for preparing the fresh corn food according to any one of the 1 st to 4 th, wherein when the fresh corn food is quick-frozen corn cobs or vacuum packaged corn cobs, the pretreatment process comprises bubbling cleaning operation and high-pressure cleaning operation, wherein water immersion type bubbling flushing is adopted in the bubbling cleaning operation, and optionally, a roller is adopted to convey the material after the bubbling cleaning operation in the high-pressure cleaning operation, so that the material is cleaned by high-pressure water in the rolling process.

6. The preparation method of the fresh corn food according to any one of the 1 st to 5 th, wherein when the fresh corn food is quick-frozen corn cobs or vacuum packaged corn cobs, the post-treatment process comprises a first cooling operation, and optionally, in the first cooling operation, the material after the enzyme deactivation process is immersed into cooling water for cooling, wherein the temperature of the cooling water is 4 ℃ to 30 ℃ and the cooling time is 2 to 8 minutes.

7. The method for preparing a fresh corn food according to any one of the 1 st to 6 th, wherein when the fresh corn food is a vacuum packed corn cob, the post-treatment process further comprises a vacuum packing operation, a sterilization operation and a foreign matter detection operation, wherein the sterilization temperature is optionally 110 ℃ to 130 ℃, the sterilization time is 18 to 30min, the pressure range in the sterilization process is 0.1mpa to 0.3mpa, or when the fresh corn food is a quick frozen corn cob, the first draining operation is followed by a first quick freezing operation and a foreign matter detection operation, and the quick freezing temperature is optionally lower than-30 ℃ in the first quick freezing operation, and the quick freezing temperature is less than-18 ℃.

8. The preparation method of the fresh corn food according to any one of the 1 st to 7 th, wherein when the fresh corn food is quick-frozen corn kernels, the pretreatment process comprises a winnowing impurity removal operation, a rotary sieving operation and a rotary washing operation, wherein in the winnowing impurity removal operation, the material is lifted to a preset height and then falls down, and wind is assisted in the falling process of the material, in the rotary sieving operation, the material subjected to the winnowing impurity removal operation is placed in a roller sieve to be subjected to rotary sieving, and in the rotary washing operation, the material subjected to the rotary sieving operation is immersed in water, and is subjected to rotary washing under the disturbance of water flow, and the material subjected to the rotary washing is placed on a screen to be subjected to spray washing.

9. The preparation method of the fresh corn food according to any one of the 1 st to 8 th, wherein when the fresh corn food is quick-frozen corn kernels, the post-treatment procedure comprises a second cooling operation, a material distribution operation, a second freezing operation, a carefully selecting operation, a quantitative packaging operation and a foreign matter detection operation, optionally, in the second cooling operation, the materials after the enzyme deactivation procedure are cooled by adopting warm water and cold water in sequence, the temperature of the cold water is 4-15 ℃, optionally, in the material distribution operation, the material distribution is carried out under the vibration condition, the thickness of the material distribution is less than 4cm, and optionally, the carefully selecting operation comprises color selection treatment and/or screening classification treatment of the materials after the second freezing operation.

10. The method for preparing a fresh corn food according to any one of the 1 to 9, wherein in the second freezing operation, the quick freezing temperature is below-30 ℃ and the center temperature of the material is below-18 ℃, and optionally, the second freezing operation is performed on the material in a quick freezing tunnel or a quick freezing warehouse.

11. A fresh corn food, such as 1-10 pieces, is prepared by the method.

The invention has at least the following beneficial effects:

The preparation method of the fresh corn food can avoid the direct contact of the fresh corn food with high temperature water in the enzyme deactivation process, so as to effectively reduce the loss of water-soluble nutrients, especially for color corn and black corn rich in anthocyanin and other nutrients, the nutrients are better preserved, and the enzyme to be deactivated is subjected to microwave enzyme deactivation in a microwave environment after being covered by the flexible protection piece, so that the enzyme to be deactivated is relatively isolated from the external environment under the coverage of the flexible protection piece.

Under the action of microwaves, the evaporated moisture generated by the material to be deactivated is reserved around the material to be deactivated so as to improve the humidity of the enzyme deactivation environment of the material to be deactivated, and different parts of the material to be deactivated are heated more uniformly, so that the phenomenon that the material to be deactivated is locally overheated to generate paste points is avoided, and the quality of fresh corn food is obviously improved. Moreover, as the microwave heating has selectivity, the microwave can perform key heating according to the characteristic of high water content of the corncob, so that the corncob is thoroughly deactivated, the whole enzyme deactivation effect of the fresh corn food is improved obviously, the shelf life of the fresh corn food is prolonged, and the fresh corn food is ensured to still maintain good quality after being stored for a long time.

Therefore, according to the method disclosed by the invention, the fresh corn is subjected to selective heating enzyme deactivation by utilizing the microwave enzyme deactivation technology, so that the enzyme deactivation effect is effectively improved, meanwhile, rich nutrients are reserved, the quality of the fresh corn food is obviously improved, and the method has wider application prospect and commercial value.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 shows a photograph of a peroxygenase activity detection of a fresh corn food prepared in example 1 of the present invention;

FIG. 2 shows a photograph of a peroxygenase activity detection of the fresh corn food prepared in comparative example 2 of the present invention;

FIG. 3 is a photograph showing the material after the enzyme deactivation process of comparative example 3 according to the present invention as it is blanched;

FIG. 4 is a photograph showing the material after cooling with normal temperature water at the time of the second cooling operation in example 4 of the present invention;

FIG. 5 shows a photograph of the fresh corn food prepared in comparative example 4 of the present invention;

fig. 6 is a schematic structural diagram of a conveying mechanism according to an exemplary embodiment of the present invention.

Detailed Description

It should be understood that the specific embodiments presented herein are for purposes of explanation to those skilled in the art and are intended to be illustrative only and not limiting.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the specific details need not be employed to practice the present invention. In other instances, well-known steps or operations have not been described in detail in order to avoid obscuring the invention.

It should be noted that, in this document, the meanings of the related terms are as follows:

the term "microwave environment" refers to an environment formed by electromagnetic waves, which have the characteristic of alternating electric field and magnetic field, when materials are in the externally applied alternating electromagnetic field, polar molecules in the materials are polarized and are alternately oriented along with the polarity change of the externally applied electromagnetic field, and a plurality of polar molecules are frequently rubbed and lost mutually, so that the electromagnetic energy is converted into heat energy.

The term "Teflon high-temperature cloth" refers to a fiber cloth which is prepared by taking polytetrafluoroethylene emulsion as a raw material and impregnating high-performance glass fiber cloth.

The term "silicone tape" refers to a material made of silicone coated or compounded on a substrate such as cloth, fiber, or the like.

The term "polyester film" refers to a plastic film made of polyester resin, and the main raw material is polyethylene terephthalate (PET).

The term "water immersion bubbling rinse" refers to the use of water as a medium and introducing a gas into the water by bubbling, thereby utilizing the agitating and scouring action of the bubbles to clean or rinse the target object or surface.

The term "roller conveyor" refers to a method of conveying material in a rolling manner, such roller conveyor being illustratively accomplished by means of a device consisting of a roller and a power system, the roller being driven in rotation by a motor to convey material from one location to another in a rolling manner.

The term "blanching" also known as blanching refers to the use of a means of heat treating a vegetable food product with hot water or steam to inactivate enzymes carried by the vegetable food product itself and thereby prevent spoilage of the food product.

The term "black corn" refers to corn with black and shiny appearance, which is rich in anthocyanin, water-soluble melanin, trace elements, plant proteins and various amino acids necessary for human body, and has higher nutrition content, and can precipitate melanin in different degrees of kernel cuticle.

The term "sweet corn" is also called fruit corn, the grain contains more sugar, full and succulent, delicious and sweet corn in the milk ripening period, and the content of protein, fat, lysine and tryptophan in the grain milk tender fruit is more abundant than that of common corn.

The term "white corn" refers to a variety of corn whose kernel is predominantly white or pale yellow in color, which is rich in carbohydrates, proteins, fats, vitamins and minerals, and is commonly used to make corn products such as corn flour, corn flakes, corn starch, and the like.

The term "colored corn" refers to the color of seeds, including purple, black, red, flower color, etc., and the colored corn is obtained by cross pollination hybridization breeding of corn varieties with different colors, and has more abundant nutrition components compared with common corn.

The term "anthocyanin" also called anthocyanidin, anthocyanin is a water-soluble natural pigment widely existing in plants, and anthocyanin is a glycoside derivative, is easily dissolved in polar solvents such as water, methanol, ethanol and the like, has strong antioxidant capacity and inflammation reaction inhibiting capacity, and is favorable for protecting cells from oxidative damage, relieving symptoms of inflammatory diseases, protecting cardiovascular diseases, regulating blood sugar, improving eyesight and the like.

The present invention will be specifically described below.

The embodiment of the invention provides a preparation method of fresh corn food, which comprises the steps of sequentially carrying out pretreatment, enzyme deactivation and post-treatment on materials to be processed to prepare the fresh corn food;

According to the preparation method of the fresh corn food, the material to be processed is subjected to the pretreatment process, and the unsuitable edible parts and the excessive impurities of the material to be processed can be removed in the pretreatment process, so that the whole quality of the fresh corn food is improved. And in the process of the enzyme deactivation, the material to be deactivated is covered with a flexible protection piece, then microwave enzyme deactivation is carried out in a microwave environment, microwaves can penetrate through the flexible protection piece to directly act on the inside and the surface of the material to be deactivated, the flexible protection piece can keep evaporation water generated by the material to be deactivated around the material to be deactivated so as to improve the enzyme deactivation environment humidity of the material to be deactivated, different parts of the material to be deactivated are heated more uniformly, thereby preventing the material to be deactivated from being locally overheated to generate paste spots, remarkably improving the quality of fresh corn foods, and the microwave heating has selectivity, has stronger absorption capacity to microwaves due to higher water content (the water content of the corncob of the whole corn is generally about 80 percent), enables the corncob to be deactivated more thoroughly, is beneficial to the remarkable improvement of the whole enzyme deactivation effect of the fresh corn foods, and can further fully preserve the nutrient-soluble substances of the fresh corn foods due to the fact that the material to be deactivated is not required to be contacted with high-temperature water, the fresh corn anthocyanin is directly deactivated, and the nutrient-soluble substances are fully preserved after the nutrient substances of the fresh corn are completely treated.

It should be noted that, in the embodiment of the invention, after the flexible protection member is covered by the material to be deactivated, microwave enzyme deactivation is performed in a microwave environment, and the key purpose of the design of the flexible protection member is to fully isolate the material to be deactivated from the external environment, prevent the water generated after the material to be deactivated is heated from being lost by heat, ensure that the material to be deactivated is heated uniformly in the enzyme deactivation process, and reduce energy consumption; therefore, under the condition of meeting the aim, when the flexible protection piece covers the materials to be deactivated, the exposed surfaces of all the materials to be deactivated can be covered, namely, the surfaces of the materials to be deactivated are completely wrapped to form a relatively airtight enzyme deactivation environment, or the flexible protection piece can be covered on at least one surface of the materials to be deactivated and form the relatively airtight enzyme deactivation environment together with a mechanism for supporting the materials to be deactivated, so that moisture generated when the materials to be deactivated are heated is kept around the materials to be deactivated.

Furthermore, the fresh corn food prepared by the preparation method of the embodiment of the invention can be products prepared by taking fresh corn as raw materials, such as quick-frozen corn cobs, vacuum-packaged corn cobs, quick-frozen corn kernels and the like, and the pretreatment process and the post-treatment process in the preparation method of the embodiment can be adaptively adjusted when facing different target products.

For example, when the target product is whole corn such as vacuum packaging corn cob, the head and tail parts of the whole corn cob can be cut off in the pretreatment process, and the whole corn cob after the head and tail parts are cut off is cleaned and decontaminated and then subjected to the enzyme deactivation process, and when the target product is quick-frozen corn cob, the whole corn cob can be threshed in the pretreatment process, removed, cleaned and decontaminated and then subjected to the enzyme deactivation process.

Therefore, the material to be deactivated in the embodiment of the invention can be whole corn (namely corn cob) or corn kernels, the whole corn or corn kernels are subjected to microwave enzyme deactivation in a microwave environment after being covered by the flexible protection piece, so that the whole corn or corn kernels do not need to be contacted with flowing water with higher temperature to avoid loss of water-soluble nutrients such as pigments and soluble sugar, and especially when the material to be deactivated is whole corn, the preparation method of the embodiment can further fully inactivate peroxidase in corn cobs so as to improve the shelf life of fresh corn foods and ensure that the fresh corn foods still keep good quality after being stored for a long time.

In order to facilitate industrial continuous production, in some alternative embodiments, the enzyme deactivation process specifically comprises the steps of covering the flexible protection member with the material to be deactivated, conveying the material under a microwave environment, and inactivating the enzyme for a first preset time by microwaves. Through will wait to kill behind the enzyme material cover flexible protection piece and carry under the microwave environment, the first scheduled time of microwave enzyme deactivation, wait to kill the enzyme material and produce heat and evaporation moisture under the microwave environment, flexible protection piece can restrain the loss of the evaporation moisture that wait to kill the production of enzyme material, promotes the ambient humidity around the material of waiting to kill the enzyme for wait to kill the enzyme material and be heated more even while, reduce the loss of heat and moisture, ensure that the enzyme inactivation of fresh corn food is more complete.

In the embodiment of the invention, the material to be deactivated is covered by the flexible protection piece and then conveyed in a microwave environment, and the material to be deactivated can be realized by adopting a conveying mechanism A (for example, a microwave treatment device with a conveying belt is designed) provided with more than 1 microwave generators d, so that the microwave environment required by the enzyme deactivation process is formed, the flexible protection piece can form a relatively airtight enzyme deactivation environment with the conveying mechanism A after covering the material to be deactivated on the conveying mechanism A, and the continuous production requirement of the preparation method provided by the embodiment of the invention in industrialized application can be met by carrying out the enzyme deactivation process through the conveying mechanism A provided with the microwave generators d.

In order to avoid the ambiguity of the person skilled in the art, referring to fig. 6, an embodiment of the invention exemplarily provides a conveying mechanism A suitable for an enzyme deactivation process, wherein the conveying mechanism A comprises a feeding system a, a transmission belt b, a microwave inhibition system c, a microwave generator d, a microwave action cavity e, a moisture discharging system f and a discharging system g, wherein one or more microwave generators d (6 microwave generators d shown in fig. 6) can be designed in the microwave action cavity e, the microwave generator d can generate a microwave environment in the microwave action cavity e, the microwave generator d is beneficial to reducing the enzyme deactivation process time of materials to be deactivated, improving the treatment capacity and the treatment efficiency of the materials to be deactivated, the microwave inhibition system c is arranged outside the microwave action cavity e to block microwaves, prevent and control the microwave leakage, ensure the safe operation of equipment, the moisture discharging system f is communicated with the microwave action cavity e and is used for discharging moisture in the microwave action cavity e, the transmission belt b can also be designed into one or a plurality of (6 microwave generators d shown in fig. 6), the microwave generators d can be arranged between the transmission belt b and the microwave action cavity e in the microwave action cavity e, the microwave inhibition system b can cover the microwave action cavity b and the microwave action cavity b in the middle of the microwave action cavity e, and the material to be protected, and the material to be subjected to the enzyme deactivation process is carried out, and the microwave deactivation process is conveniently carried out, and the microwave deactivation material is carried out by the microwave deactivation system has been protected, and the microwave deactivation material has been subjected to the microwave deactivation process has been reduced.

It should be noted that, the conveying mechanism a may use a water cooling system (not shown) to dissipate heat so as to maintain the equipment temperature constant, the application environment temperature of the conveying mechanism a should be greater than 0 ℃ and less than 40 ℃, and the application environment temperature is below 0 ℃ to easily cause the cooling water in the water cooling system to be frozen, thereby affecting the heat dissipation efficiency, and the application environment temperature is above 40 ℃ to easily cause poor heat dissipation of related components of the equipment, thereby affecting the service life of the equipment.

In alternative embodiments of the invention, the first preset time is 1-10 min, preferably 4-10 min, for example, the first preset time can be 1min、1.5min、2min、2.5min、3min、3.5min、4min、4.5min、5min、5.5min、6min、6.5min、7min、7.5min、8min、8.5min、9min、9.5min、10min or a time range defined by any two of the first preset time, when the first preset time is less than 1min, the microwave enzyme deactivation time is shorter, so that the fresh corn food is incomplete in enzyme deactivation and poor in product quality, and when the first preset time is more than 10min, the microwave enzyme deactivation time is too long, so that the production efficiency is greatly reduced, the energy consumption is higher, the first preset time in the time range can enable the fresh corn food to be fully deactivated, the effective utilization rate of energy is higher, pigment and nutritional ingredients of the fresh corn food can be better reserved, the quality is better, and the first preset time of the microwave enzyme deactivation can be adaptively selected in the range according to different treatment amounts of materials to be deactivated.

In some alternative embodiments, the enzyme deactivation process further comprises stopping microwave treatment of the microwave enzyme deactivated material, and maintaining the temperature for a second predetermined time, wherein the microwave enzyme deactivated material is stopped and maintained, and at the moment, the microwave enzyme deactivated material is still covered with the flexible protection member, so that heat in the enzyme deactivation environment can be fully preserved, and the temperatures of different parts of the material can be further balanced in the heat preservation process under the environment with higher humidity, so that the situation that the enzyme deactivation of all parts of fresh corn foods can be fully realized is ensured. In addition, the heat preservation design effectively reduces the time for supplying microwaves, is beneficial to saving energy and improving the safety of production environment, and can further reduce the loss of nutrient substances of fresh corn foods.

In some alternative embodiments, the second preset time is 0.1-10 min, for example, the second preset time can be 0.1min、1min、1.5min、2min、2.5min、3min、3.5min、4min、4.5min、5min、5.5min、6min、6.5min、7min、7.5min、8min、8.5min、9min、9.5min、10min or a time range defined by any two of the two, and the heat preservation is carried out within the second preset time range, so that the temperature difference of different parts of the materials subjected to microwave enzyme deactivation is balanced, the corn temperature after the microwave enzyme deactivation is ensured to be uniform, the moisture and nutrient substances in the corn are better preserved, meanwhile, the enzymes of all parts of the fresh corn food are fully inactivated, and the good quality of the fresh corn food is ensured to be still maintained after the fresh corn food is stored for a long time.

In some alternative embodiments, the flexible guard comprises at least one of teflon high temperature cloth, silicone cloth, or mylar. The material is used as a flexible protection piece and has the characteristics of high flexibility, high temperature resistance, water resistance and no toxicity, and the material is covered on the surface of the material to be deactivated in the enzyme deactivation process, so that the material can adapt to the shape of the material to be deactivated and is tightly attached to the material to be deactivated, thereby effectively retaining the moisture and heat generated by the material to be deactivated after the action of microwaves, enabling the temperatures of different parts of the material to be deactivated in the enzyme deactivation process to be more balanced, and enabling the enzyme of fresh corn food to be fully deactivated, and simultaneously having rich nutritive value and excellent quality.

In some alternative embodiments, when the fresh corn food is a vacuum packaged corn cob, the pretreatment process sequentially comprises an acceptance inspection operation, a peeling and filament removing operation, a head and tail cutting operation, a bubbling cleaning operation and a high-pressure cleaning operation.

It can be understood that when the fresh corn food is quick-frozen corn cob or vacuum-packed corn cob, the material is corn cob in the whole process of the preparation method, in the pretreatment process, the material to be processed is subjected to acceptance operation according to preset acceptance criteria in aspects of plumpness of grains, cob shape, color, variety, maturity, foreign matter condition and the like of whole corn cob, the material to be processed is accepted, so that the fresh corn food is better in quality, then the accepted material is subjected to peeling and filament removing operation, larger impurities such as corn husks and filaments are removed, so that the subsequent impurity removing cost is reduced, the corn cob with color, cob shape, size and old and tender corn cob which do not meet requirements can be further removed in the head and tail cutting operation, the corn cob with better appearance quality obtained after selection is cut off, the corn cob is more close in size in the subsequent preparation process, uniform processing is facilitated, the corn cob is better in quality, the corn cob is better in product consistency of fresh corn food is facilitated to be improved, the corn cob with the product quality after the acceptance operation is further carried out, the corn cob is removed, the impurity is better in the surface of the corn cob is removed, the impurity is more easily cleaned, and the impurity is more difficult to clean, and the impurity is removed from the surface of the corn cob is more clean, and the corn cob is better in the quality, and the impurity is more clean, and the impurity is removed, and the impurity is more clean.

In some alternative embodiments, when the fresh corn food is a quick-frozen corn cob, the pretreatment process sequentially comprises an acceptance check operation, a peeling and filament removing operation, a bubbling cleaning operation and a high-pressure cleaning operation. It can be understood that in the process of preparing the fresh corn food into the quick-frozen corn cob, the quick-frozen corn cob is peeled off and the filament is removed, and then the head and tail cutting operation is not performed, so that the phenomenon that corn kernels fall off in the subsequent storage and reprocessing processes can be prevented, the product quality is improved, and the material waste is avoided.

It should be noted that, the peeling and filament removing operation in the embodiment of the invention can be realized by adopting a conventional corn peeling machine, and the head and tail cutting of the whole corn can be realized by adopting a conventional head and tail cutting device.

The bubbling cleaning operation in the embodiment of the invention is a cleaning method which uses compressed air to make water make surge motion so as to quickly separate impurities on the surface of a material. In some preferred embodiments of the invention, water immersion type bubbling flushing is adopted in bubbling cleaning operation, in the water immersion type bubbling flushing process, materials are soaked in water, water vapor is continuously supplied to the bottom of normal-temperature water to form bubbles in the water, the bubbles float upwards to form disturbance so as to clean the surfaces of the materials, foreign matters such as corn silk or leaves which are easy to separate in the materials float on the water surface, and the foreign matters can be further removed through a circulating filtering system. The water immersion bubbling flushing has too short cleaning time, can not thoroughly clean dirt and impurities on the surface of the material, and can cause unnecessary damage to the material if the cleaning time is too long, such as nutrition loss, poor taste and the like, so that the water immersion bubbling flushing time is controlled to be within the range of 2-8 min, the cleaning effect can be ensured within the time range, and meanwhile, the unnecessary damage to the material caused by the too long cleaning time is avoided.

For corn cobs, corn kernels are usually closely arranged on the surface of the corn cobs, foreign matters in gaps of the corn kernels are required to be washed by high-pressure water, in the high-pressure washing operation, a rolling rod is used for conveying materials subjected to bubbling washing operation, so that the materials are washed by the high-pressure water in the rolling process, the rolling rod conveying can achieve the rolling of the materials in the conveying process, the materials can be washed by the high-pressure water for 360 degrees, the high-pressure water and the materials can be separated in time, the foreign matters are not easy to remain, the water carrying the foreign matters is recycled by the high-pressure pump after being circularly filtered, so that water resource consumption in the high-pressure washing operation is reduced, washing uniformity and washing efficiency are improved, and stubborn dirt on the surfaces of the materials is removed more effectively.

The high-pressure cleaning operation is carried through high-pressure water flow and roller and combines together the mode for the material that waits to wash accepts the scouring of high-pressure water at the in-process that rolls, in order to ensure that dirt and impurity on material surface are effectively got rid of, avoid too long cleaning time to cause unnecessary harm to the material simultaneously, the time control of high-pressure cleaning operation is in 2~8min scope to be suitable.

Further, where the fresh corn food product is a quick frozen corn cob or a vacuum packed corn cob, in some alternative embodiments, the post-treatment process includes a first cooling operation and a first draining operation in sequence.

It can be understood that the corn cob material after the enzyme deactivation process has higher temperature (about 90-98 ℃ and the temperature distribution of each part of the corn cob material is uniform), the corn cob can be cooled in time by carrying out the first cooling operation on the material after the enzyme deactivation process so as to prevent further loss of the nutrition components of the material and growth of microorganisms, slow down the quality degradation during subsequent quick freezing or vacuum packaging, and further carry out the first draining operation on the material after the first cooling operation so as to fully remove the cooling water on the surface of the material after the first cooling operation, thereby facilitating quick freezing or vacuum packaging treatment in the subsequent process.

In some alternative embodiments, in the first cooling operation, the material after the enzyme deactivation process is immersed in cooling water for cooling, the temperature of the cooling water is 4-30 ℃, and cooling is performed by cooling water with the temperature of 4-30 ℃, so that the quality degradation and microorganism propagation of the material after the enzyme deactivation process caused by long-time high-temperature state can be prevented, and corn kernels in the material recover a certain moisture content to a certain extent, and the taste and nutritive value of the corn kernels are maintained. In the aspect of time control of the first cooling operation, the cooling time is too short, the material may not be completely cooled, residual heat may affect the subsequent processing steps and product quality, while the cooling time is too long, although the material can be ensured to be completely cooled, energy and time may be wasted, and excessive cooling may also cause adverse effects on the material, so that the cooling time is controlled to be 2-8 min, and the material can be sufficiently cooled, and meanwhile, the excellent quality of fresh corn food is ensured.

In order to improve the draining effect and the requirement of industrial continuous production, in some optional embodiments, in the first draining operation, a chain is used for conveying the material subjected to the first cooling operation, draining is performed, air drying is assisted, the draining time is 1-8 min, and when the air drying is performed, a 1-6 fans are arranged in the top space of the chain for conveying, so that cooling water on the surface of the material can be quickly dried within the time range, and the continuous production requirement of industrial application is further met.

When the fresh corn food is vacuum packed corn cob, in some optional embodiments, the first draining operation is followed by vacuum packing operation, sterilization operation and foreign matter detection operation sequentially, the cooling water on the surface of the material after the first draining operation is sufficiently removed, the quality guarantee period of the fresh corn food can be effectively prolonged and oxidation and microorganism growth can be prevented by vacuum packing the material after the first draining operation, the safety of the fresh corn food can be further improved and the quality guarantee period can be further prolonged by further performing sterilization operation on the material after the vacuum packing operation, and the foreign matter possibly introduced in the preparation process such as screw caps, screws, welding slag and other metal foreign matters can be removed by performing foreign matter detection operation on the material after the sterilization operation, so that the risk of food safety is reduced and the quality of the fresh corn food is improved.

In some embodiments of the invention, the vacuum packaging operation adopts a vacuum packaging machine to vacuumize and package the corn cob material after the first draining operation, and a steaming and boiling resistant packaging bag can be used for packaging so as to improve convenience in eating.

In some embodiments of the invention, sterilization operation can be performed in a sterilization kettle, in order to ensure a sterilization effect, sterilization temperature is controlled to be 110-130 ℃, sterilization time is controlled to be 18-30 min, pressure is controlled to be 0.1-0.3 mpa in a sterilization process, and secondary cooling is performed after sterilization is finished, so that a finished vacuum packaged corn cob food is obtained. Before sterilization operation, the corn cob material has higher initial temperature at the center after microwave enzyme deactivation, so that the sterilization strength can be further improved in the sterilization process, and the microbial risk of the product is reduced.

When the fresh corn food is quick-frozen corn cob, in some optional embodiments, the first draining operation is followed by a first quick-freezing operation and a foreign matter detection operation, wherein the first quick-freezing operation can be used for quick-freezing materials after the first draining operation by adopting a quick-freezing tunnel or a quick-freezing warehouse, the quick-freezing temperature is below-30 ℃ in the first quick-freezing operation, the quick-freezing time is more than 20 minutes so as to ensure that the temperature of the quick-frozen materials to the center (the center of the corn cob) is less than-18 ℃, and the foreign matter possibly introduced in the preparation process, such as screw caps, screws, welding slag and other metal foreign matters, can be removed by carrying out the foreign matter detection operation on the materials after the first quick-freezing operation, so that the risk of food safety is reduced, and the quality of the fresh corn food is improved.

It should be noted that, when fresh corn food is quick-frozen corn cob, the first cooling operation can adopt cooling water and frozen water to cool down the material after the enzyme deactivation process in proper order, and the material is cooled down after cooling water, and the secondary cooling of the frozen water again can effectively reduce quick-freezing equipment's load for quick-freezing efficiency obtains further improvement.

In some alternative embodiments, when the fresh corn food is quick-frozen corn kernels, the pretreatment process sequentially comprises checking and accepting operation, peeling and filament removing operation, threshing operation, air separation and impurity removing operation, rotary sieving operation and rotary washing operation.

It can be understood that when the fresh corn food is quick-frozen corn kernels, in the pretreatment procedure, the material to be processed is subjected to checking and accepting operation according to preset checking and accepting standards in aspects of full grain, stick shape, color, variety, maturity, foreign matter condition and the like of whole corn, the material to be processed is checked and accepted to be favorable for ensuring that the fresh corn food has more excellent quality, then the checked material is subjected to peeling and filament removing operation to remove larger impurities such as corn husks and filaments and the like so as to be favorable for reducing the subsequent impurity removing cost, the corn cob material after the peeling and filament removing operation is subjected to threshing operation to remove corn cobs of corn cobs so as to obtain corn kernel material, and as the corn kernel material obtained after the threshing operation inevitably has more impurities, the material after the threshing operation is subjected to winnowing and impurity removing operation so as to remove light-density impurities in the material, and the material after the winnowing impurity removing operation is subjected to rotating operation so as to further remove impurities (such as to remove impurities with large size and small size) and impurities (such as corn husks), and the material after the rotating and sieving operation is subjected to rotating operation so as to be favorable for preparing the quick-frozen corn kernels.

In some optional embodiments of the present invention, the material after threshing is lifted to a preset height and then falls, and the material falls with the aid of wind, so that the light-density impurities such as corn silk and corn husks can be fully separated from corn grains under the action of the difference of wind power and gravity.

In the optional embodiment of the invention, the material subjected to the winnowing impurity removal operation is placed in a roller screen for rotary sieving, the roller screen is two layers of roller screens, the aperture of an inner layer screen is about 1.5-2 cm round holes, the width of an outer layer screen is about 0.5cm and the length of the outer layer screen is 1cm elliptical holes, so that large-size foreign matters can be left in the inner layer screen, small-size foreign matters are removed through the outer layer screen, and the material reserved in the middle layer of the outer layer screen and the inner layer screen is the qualified-size corn grain material, so that the large-size foreign matters and the small-size foreign matters in quick-frozen corn grains, especially broken corn grains, can be effectively removed.

In order to further remove less dense impurities, in alternative embodiments of the invention, the spin-rinse operation comprises immersing the spin-screened material in water, spin-rinsing with a disturbance of the water flow, and spray rinsing the spin-washed material on a screen. Specifically, the rotary washing operation is carried out by adopting the rotary washing machine, the materials after the rotary sieving operation are immersed in water, water is supplied by a water spray pipe at the bottom of the water to form water flow disturbance, so that the corn grain surface layer is subjected to rotary washing, impurities with smaller relative density can float on the water surface and be discharged, the corn grain materials subjected to rotary washing are placed on a single-layer screen for spray washing, the screen consists of two sections, the front section of the screen is small in aperture, the screen aperture is an elliptical aperture with the width of about 0.5cm and the length of 1cm, so that small-size impurities are further sieved, the rear section of the screen is larger, the aperture size is round holes with the diameter of about 1.5 cm to 2cm, qualified-size materials can leak out through the screen, and large-size impurities are reserved in the screen for further sieving large-size impurities, so that the corn grain materials which are cleaner and qualified in size are obtained.

In some optional embodiments of the present invention, the post-treatment process comprises a second cooling operation, a second draining operation, a distributing operation, a second freezing operation, a beneficiation operation, a quantitative packaging operation, and a foreign matter detection operation in that order. The material after the enzyme deactivation process has higher temperature, the temperature of the corn kernel material can be obviously reduced after the second cooling operation so as to be beneficial to improving the processing capacity and quick-freezing efficiency in the subsequent quick freezing process, the cooling water on the surface of the corn kernel can be fully dried after the second draining operation so as to reduce ice crystals of quick-frozen corn kernel products and improve the quality of fresh corn foods, the material after the second draining operation can be more uniformly laid in quick-freezing equipment so as to improve the quick-freezing efficiency, the material after the material distribution operation can be quickly reduced to extremely low temperature after the second freezing operation so as to preserve the original nutritional ingredients and flavor of the corn kernel to the greatest extent, the material after the second freezing operation can be screened and graded to ensure the product quality consistency of the fresh corn foods after the selection operation, the material after the quantitative packaging operation can be ensured to be consistent in quantity of products in each package, and further carry out the quantitative packaging operation so as to detect foreign matters such as to introduce foreign matters into the prepared fresh food, such as fresh screw caps, and the like, and the risk of safety is reduced.

In some optional embodiments of the invention, in the second cooling operation, the materials after the enzyme deactivation process are cooled by adopting the warm water and the cold water in sequence, the temperature of the cold water is 4-15 ℃, compared with single cooling, the materials after the enzyme deactivation process are cooled twice by adopting the warm water and the cooling water of 4-15 ℃, so that the temperature of the corn grain materials before the second freezing process can be obviously reduced, and the processing capacity and the quick freezing efficiency during the quick freezing process can be improved.

Because the second cooling operation adopts water cooling, in some alternative embodiments of the invention, in the second draining operation, the belt Kong Liandao is adopted to convey the material after the second cooling operation, draining is carried out, air drying is assisted, and the belt Kong Liandao is adopted to convey the material after the second cooling operation, so that the cooling moisture on the surface of the corn kernels can be naturally dropped, and meanwhile, the air drying equipment provided with a fan is assisted for air supply and drying, so that the redundant moisture on the surface of the corn kernels is rapidly removed.

In order to improve the quick-freezing efficiency, in some optional embodiments of the invention, in the material distribution operation, the material after the second draining operation is subjected to material distribution treatment under the vibration condition, so that the corn grain material distribution is more uniform, the condition of caking or uneven thickness is avoided in the second freezing operation process, and the material distribution thickness is less than 4cm, so that the quick-freezing effect can be ensured, and the corn grain can quickly and uniformly reach the required low-temperature state.

In some optional embodiments of the invention, the selecting operation comprises color selection treatment and/or screening classification treatment of the materials after the second freezing operation, wherein the color selection treatment can automatically sort different-color particles in the corn kernel materials by adopting color selection equipment so as to improve the consistency of quick-frozen corn kernel products, the screening classification treatment can screen out corn particles by adopting a classification vibrating screen and ice crystals generated by quick freezing, and meanwhile, the corn kernel materials adhered together are separated by vibrating so as to improve the quality of the quick-frozen corn kernel products and ensure the excellent quality of fresh corn foods.

In some optional embodiments of the invention, in the second freezing operation, the low temperature environment with the quick freezing temperature below minus 30 ℃ and minus 30 ℃ can quickly reduce the temperature of the corn kernel material, so that the nutritional ingredients and flavor of the corn kernels are reserved to the greatest extent, the quick freezing temperature is lower than minus 18 ℃ until the temperature of the center of the material, the growth of microorganisms and the activity of enzymes can be effectively prevented, and the shelf life of the quick frozen corn kernel product is prolonged.

In order to facilitate industrial continuous production, in some alternative embodiments of the invention, the first freezing operation and the second freezing operation freeze the material in a quick freezing tunnel or a quick freezing warehouse. The quick-freezing tunnel is usually a closed channel, and when the material passes through the conveyor belt, the material can be surrounded by continuous cold air flow so as to implement quick and uniform cooling, and the quick-freezing warehouse is a large space in which a refrigerating device and a circulating fan are mounted so as to ensure the stability and uniformity of the temperature in the warehouse.

In some alternative embodiments of the present invention, the foreign matter detection operation includes detecting the material with a metal detection device, for example, the metal detection device may be a metal detector, so as to efficiently and accurately detect the metal foreign matter possibly existing in the material, thereby improving the safety of the fresh corn food.

When the fresh corn food is quick-frozen corn kernels or quick-frozen corn cobs, in some optional embodiments of the invention, the quick-frozen corn kernels or quick-frozen corn cobs obtained after the foreign matter detection operation are frozen by a freezer, and the freezing temperature is less than-18 ℃ so as to inhibit the growth of microorganisms in the fresh corn food and promote the original flavor, taste and nutritional value of the fresh corn food to be retained to a great extent.

The invention also provides a fresh corn food, which is prepared by the preparation method of the embodiment.

The present invention will be further described in detail with reference to the following specific embodiments for the purpose of making the objects, technical solutions and advantageous effects of the present invention more apparent, but the described specific embodiments are only for explaining the present invention and are not intended to limit the present invention.

Example 1

A preparation method of a color corn vacuum packaging corn cob comprises the following specific steps:

1. Pretreatment process

1) And checking and accepting the material to be processed by taking the color corn cobs as raw materials according to preset checking and accepting standards on the plumpness, the stick-shaped size, the color, the variety, the maturity and the foreign matters of the raw materials to obtain the checked and accepted material.

2) Peeling and removing the filaments, namely peeling the accepted materials which are accepted by inspection, and removing the corn husks and the filaments to obtain the materials after peeling and removing the filaments;

3) And (3) head and tail cutting operation, namely primarily selecting the materials after the peeling and filament removing operation, removing corn cobs with unsatisfactory color, stick shape, size and tenderness, and cutting the heads and tails of the corn cobs with good appearance and quality obtained after selection to obtain the materials after the head and tail cutting operation.

4) And the bubbling cleaning operation is to flush the material subjected to the head and tail cutting operation by water immersion type bubbling, wherein the time of the bubbling cleaning operation is controlled to be 2 minutes, so as to obtain the material subjected to the bubbling cleaning operation.

5) And (3) high-pressure cleaning operation, namely conveying the material subjected to the bubbling cleaning operation by adopting a rolling rod, so that the material subjected to the bubbling cleaning operation is subjected to cleaning by high-pressure water in the rolling process, and the time of the high-pressure cleaning operation is controlled to be 2min, so as to obtain the material to be deactivated.

2. Enzyme deactivation process

And after the material to be deactivated is covered with the Teflon high-temperature cloth, conveying the material through a conveying mechanism A in a microwave environment, inactivating enzymes by microwaves for 4min, and preserving heat for 4min, wherein the conveying mechanism A is provided with 4 microwave generators d.

3. Post-treatment process

1) And the first cooling operation, namely placing the materials after the enzyme deactivation process into cooling water for cooling, wherein the temperature of the cooling water is 4 ℃, and the first cooling operation time is 2min.

2) And the first draining operation is to convey the materials subjected to the first cooling operation by using a chain, drain the materials, and assist in air drying, wherein the draining time is 1min, and 6 fans are arranged in the top space of the chain.

3) And vacuum packaging, namely vacuum packaging the material subjected to the first draining operation.

4) Sterilizing the vacuum packaging in a sterilizing kettle at 120 deg.C for 24min under pressure of 0.2Mpa;

5) And the foreign matter detection operation, namely detecting the sterilized material by adopting metal detection equipment to remove metal foreign matters so as to obtain the color corn vacuum packaging corn cob.

Example 2

A preparation method of black corn quick-frozen corn cobs comprises the following specific steps:

1. Pretreatment process

1) And checking and accepting the material to be processed by taking the black corn as a raw material and checking and accepting the plumpness, the stick shape size, the color, the variety, the maturity and the foreign matter condition of the raw material according to preset checking and accepting standards to obtain the checked and accepted material.

4) And the bubbling cleaning operation is to flush the material subjected to the head and tail cutting operation by water immersion type bubbling, wherein the time of the bubbling cleaning operation is controlled to be 5min, so as to obtain the material subjected to the bubbling cleaning operation.

5) And (3) high-pressure cleaning operation, namely conveying the material subjected to the bubbling cleaning operation by adopting a rolling rod, so that the material subjected to the bubbling cleaning operation is subjected to cleaning by high-pressure water in the rolling process, and the time of the high-pressure cleaning operation is controlled to be 5min, so as to obtain the material to be deactivated.

2. Enzyme deactivation process

The method comprises the steps of covering a Teflon high-temperature cloth with a material to be deactivated, conveying the material in a microwave environment through a conveying mechanism A, inactivating the enzyme by microwaves for 7min, stopping microwave treatment on the material subjected to microwave enzyme inactivation, and preserving the heat for 5min, wherein the conveying mechanism A is provided with 3 microwave generators d.

3. Post-treatment process

1) And the first cooling operation, namely placing the materials after the enzyme deactivation process into cooling water for cooling, wherein the temperature of the cooling water is 17 ℃, and the first cooling operation time is 5min.

2) And the first draining operation is to convey the materials subjected to the first cooling operation by using a chain, drain the materials, and assist in air drying, wherein the draining time is 5min, and 5 fans are arranged in the top space of the chain.

3) And the first quick freezing operation, namely quick freezing the material subjected to the first draining operation by using a quick freezing tunnel, wherein the quick freezing temperature is below minus 30 ℃, and the quick freezing temperature is lower than minus 18 ℃ until the center temperature of the material is lower than minus 18 ℃.

4) And (3) detecting the foreign matters by adopting metal detection equipment to detect the materials subjected to the first quick freezing operation so as to remove the metal foreign matters and obtain the black corn quick-frozen corn cobs.

Example 3

A preparation method of vacuum packed corn cobs of sweet corn comprises the following specific steps:

1. Pretreatment process

1) And the checking and accepting operation is to take sweet corn cobs as raw materials, and check and accept the materials to be processed according to preset checking and accepting standards on the plumpness, stick-shaped size, color, variety, maturity and foreign matters of the raw materials to obtain the checked and accepted materials.

4) And the bubbling cleaning operation is to flush the material subjected to the head and tail cutting operation by water immersion type bubbling, wherein the time of the bubbling cleaning operation is controlled to be 8 minutes, so as to obtain the material subjected to the bubbling cleaning operation.

5) And (3) high-pressure cleaning operation, namely conveying the material subjected to the bubbling cleaning operation by adopting a rolling rod, so that the material subjected to the bubbling cleaning operation is subjected to cleaning by high-pressure water in the rolling process, and the time of the high-pressure cleaning operation is controlled to be 8min, so as to obtain the material to be deactivated.

2. Enzyme deactivation process

The method comprises the steps of covering a Teflon high-temperature cloth with a material to be deactivated, conveying the material in a microwave environment through a conveying mechanism A, inactivating the enzyme by microwaves for 10min, stopping microwave treatment on the material subjected to microwave enzyme inactivation, and preserving the heat for 10min, wherein the conveying mechanism A is provided with 4 microwave generators d.

3. Post-treatment process

1) And the first cooling operation, namely placing the materials after the enzyme deactivation process into cooling water for cooling, wherein the temperature of the cooling water is 30 ℃, and the first cooling operation time is 8min.

2) And the first draining operation is to convey the materials subjected to the first cooling operation by using a chain, drain the materials, and assist in air drying, wherein the draining time is 8min, and 4 fans are arranged in the top space of the chain.

3) And vacuum packaging, namely vacuum packaging the materials subjected to the first draining operation, and vacuum packaging the corn cobs by the sweet corn.

Example 4

A preparation method of black corn quick-frozen corn kernels comprises the following specific steps:

1. Pretreatment process

2) Peeling and removing the filaments, namely peeling the accepted materials which are accepted by inspection, and removing the corn husks and the filaments to obtain the materials after peeling and removing the filaments.

3) Threshing operation, namely threshing the materials after peeling and filament removing operation to obtain the materials after threshing operation.

4) And winnowing and impurity removing operation, namely lifting the materials after threshing operation to a preset height, and then falling, and blowing in the material falling process to obtain the materials after winnowing and impurity removing operation.

5) And (3) rotary sieving, namely placing the materials subjected to the air separation impurity removal operation into a roller sieve for rotary sieving to obtain the materials subjected to the rotary sieving operation.

6) And (3) rotary water washing operation, namely immersing the materials subjected to the rotary sieving operation into water, carrying out rotary water washing under the disturbance of water flow, and placing the materials subjected to the rotary water washing on a screen for spray washing to obtain the materials to be deactivated.

2. Enzyme deactivation process

The method comprises the steps of covering a Teflon high-temperature cloth with a material to be deactivated, conveying the material in a microwave environment through a conveying mechanism A, inactivating the enzyme by microwaves for 1min, stopping microwave treatment on the material subjected to microwave enzyme inactivation, and preserving the temperature for 5min, wherein the conveying mechanism A is provided with 4 microwave generators d.

3. Post-treatment process

1) And a second cooling operation, namely cooling the materials after the enzyme deactivation process by adopting warm water and cold water in sequence, wherein the temperature of the cold water is 4-10 ℃.

2) And a second draining operation, namely conveying the materials subjected to the second cooling operation by using a belt Kong Liandao, draining and assisting in air drying.

3) And (3) material distribution, namely carrying out material distribution treatment on the material subjected to the second draining operation under the vibration condition, wherein the thickness of the material after the material distribution operation is 1cm.

4) And (3) quick-freezing the material after the material distribution operation by adopting a quick-freezing tunnel, wherein the quick-freezing temperature is-36 ℃, the quick-freezing time is 10min, and the center temperature of the corn kernel material after the quick-freezing is finished is less than-18 ℃.

5) Selecting, namely screening out corn particles and ice crystals in the materials after the second freezing operation by using a classifying vibration sieve, and simultaneously vibrating and separating the corn particle materials which are adhered together, and further automatically sorting out heterochromatic particles in the materials after the classifying vibration sieve treatment by using a color selector.

6) And (3) quantitatively packaging the materials after the carefully selecting operation to ensure that the quantity of products in each package is consistent.

7) And (3) detecting the foreign matters by adopting metal detection equipment to detect the materials after the quantitative packaging operation, and removing the metal foreign matters in the materials to obtain the black corn quick-frozen corn kernels.

8) And (3) freezing and storing, namely warehousing and freezing and storing the black corn quick-frozen corn kernels, wherein the freezing and storing temperature is less than-18 ℃.

Example 5

A preparation method of quick-frozen corn kernels of sweet corn comprises the following specific steps:

1. Pretreatment process

2. Enzyme deactivation process

The method comprises the steps of covering a Teflon high-temperature cloth with a material to be deactivated, conveying the material in a microwave environment through a conveying mechanism A, inactivating the enzyme by microwaves for 6min, stopping microwave treatment on the material subjected to microwave enzyme inactivation, and preserving the heat for 3min, wherein the conveying mechanism A is provided with 3 microwave generators d.

3. Post-treatment process

7) And (3) detecting the foreign matters by adopting metal detection equipment to detect the materials after the quantitative packaging operation, and removing the metal foreign matters in the materials to obtain the quick-frozen corn kernels of the sweet corn.

Example 6

1. Pretreatment process

2. Enzyme deactivation process

And (3) covering the Teflon high-temperature cloth with the material to be deactivated, conveying the material in a microwave environment through a conveying mechanism A, inactivating the enzyme for 10min by microwaves, and preserving the heat for 2min, wherein the conveying mechanism A is provided with 3 microwave generators d.

3. Post-treatment process

Comparative example 1

1. Pretreatment process

3) And the spraying and cleaning operation is to convey the materials subjected to the peeling and filament removing operation by adopting a rolling rod, so that the materials subjected to the peeling and filament removing operation are subjected to the cleaning of high-pressure water in the rolling process, and the materials subjected to the spraying and cleaning operation are obtained.

4) And (3) head and tail cutting operation, namely, carrying out preliminary selection on the materials after the spraying and cleaning operation, removing corn cobs with unsatisfactory color, stick shape, size and tenderness, and cutting off the heads and tails of the corn cobs with good appearance and quality obtained after selection to obtain the materials to be deactivated.

2. Enzyme deactivation process

And (3) blanching and inactivating enzyme of the material to be inactivated by using hot water at 95 ℃ for 8min, so that corn kernels on the surface layer of the material are primarily retarded.

3. Post-treatment process

1) And a first cooling operation, namely cooling the materials after the enzyme deactivation process in warm water for 3min.

3) And (3) quick-freezing the material subjected to the first draining operation by using a quick-freezing tunnel, wherein the quick-freezing temperature is below-30 ℃ and the quick-freezing temperature is below-18 ℃ until the center temperature of the material is less than-18 ℃ to obtain the black corn quick-frozen corn cob.

Comparative example 2

1. Pretreatment process

2. Enzyme deactivation process

3. Post-treatment process

Comparative example 3

1. Pretreatment process

3) Threshing and cleaning, namely threshing the materials after peeling and filament removing operation, and cleaning the threshed materials to obtain the materials to be deactivated.

2. Enzyme deactivation process

And (3) putting the material to be deactivated into hot water, blanching and inactivating enzyme, wherein the blanching temperature is 95 ℃, the blanching time is 10min, the hot water is directly contacted with the corn kernel material in the blanching process, and the blanching water is heated by steam.

3. Post-treatment process

1) And a second cooling operation, namely cooling the materials after the enzyme deactivation process by adopting warm water.

2) And the selecting operation is to manually select the materials after the second cooling operation and remove foreign matters such as abnormal color grains, broken grains, corn silk, scraps and the like.

3) And a second draining operation, namely conveying the materials subjected to the selecting operation by using a belt Kong Liandao, draining and assisting in air drying.

4) And (3) quick-freezing the material after the material distribution operation by adopting a quick-freezing tunnel, wherein the quick-freezing temperature is less than-30 ℃, the quick-freezing time is more than 10min, and the center temperature of the corn kernel material after the quick-freezing is finished is less than-18 ℃.

5) And selecting, namely screening out corn particles and ice crystals in the materials after the second freezing operation by using a classifying vibrating screen, and vibrating and separating the corn particle materials adhered together.

6) And quantitatively packaging the materials after the carefully selecting operation to ensure that the quantity of products in each package is consistent, thereby obtaining the black corn quick-frozen corn kernels.

Comparative example 4

A preparation method of vacuum packed corn cob from white corn comprises the following steps:

1. Pretreatment process

1) And checking and accepting the materials to be processed according to preset checking and accepting standards on the plumpness, the stick shape size, the color, the variety, the maturity and the foreign matters of the raw materials by taking the white corn sticks as raw materials, so as to obtain the checked and accepted materials.

2. Enzyme deactivation process

The material to be deactivated is exposed in a microwave environment and is conveyed through a conveying mechanism A, the enzyme is deactivated for 4min by microwaves, the temperature is kept for 4min, and the conveying mechanism A is provided with 4 microwave generators d.

3. Post-treatment process

5) And (3) detecting the foreign matters by adopting metal detection equipment to detect the sterilized materials so as to remove the metal foreign matters, thereby obtaining the white corn vacuum packed corn cob.

In each of the above examples and comparative examples, the conveying mechanism a was derived from a microwave treatment facility of microwave equipment limited, eastern literacy, and the detailed parameter specifications were as follows:

the device model is LW-20HMV, the working frequency is 2450+/-50 MHz, the rated input apparent power is less than or equal to 25KW, the microwave output power is more than or equal to 20KW, the working process temperature is 70-200 ℃ and controllable, the device cooling mode is water cooling/air cooling, the working time is 24 hours continuously, the inlet and outlet material height is 40-100 mm, the transmission belt height is 600-1000 mm, the transmission speed is 0-4.5 m/min, the dehydration rate is 16-20 Kg/h, the external dimension (length-width-height) is 8640 x 1220 mm, the transmission belt width is 500+/-100 mm, and the microwave leakage standard is less than or equal to 5mw/cm ².

The fresh corn foods prepared according to the process methods of example 1 and comparative example 2 were cut into slices along the radial direction of the corn cob, and then were subjected to peroxidase enzyme activity detection under the same reagents, respectively, and photographs after detection are shown in fig. 1 and 2.

Photographs of the material cooled with normal temperature water at the time of the second cooling operation in example 4 were taken with normal temperature water, and photographs of the material after the enzyme deactivation process in comparative example 3 were taken with blanching water, and the obtained photographs are shown in fig. 3 and 4, respectively. The fresh corn food prepared by the process of comparative example 4 was photographed, and the photograph was obtained as shown in fig. 5.

The center temperature of the corn cob before the sterilization operation and the sterilization intensity F ₀ after the sterilization operation were measured in the preparation process of example 1 and comparative example 2, respectively, and the measurement results are shown in the following table 1:

TABLE 1 center temperature of corn cob and results of sterilization intensity detection

It should be noted that, in the embodiment of the present application, the value F ₀ refers to the reference sterilization time, that is, the equivalent sterilization time at 121 ℃, and the greater the value, the higher the sterilization strength. For example, the value of F ₀ is the time (min) equivalent to the time when the sterilization effect at a certain sterilization temperature T (sterilization temperature 126 ℃ in example 4) is the same as the sterilization effect at a value of 121° C, Z of 10 ℃ when Z is 10 ℃. The F ₀ value can be calculated using the following formula:

F₀=ΔtΣ10(T-121/Z)

wherein, the interval time tested at the temperature T is 'delta T', T is the temperature of the product sterilization time T, and Z is the temperature coefficient.

The fresh corn foods prepared in example 2, example 4, comparative example 1 and comparative example 3 were subjected to anthocyanin content detection respectively, and the detection results are shown in the following table 2:

TABLE 2 anthocyanin content detection results

According to fig. 1 and 2, compared with example 1, the color of the corn cob of the fresh corn food in comparative example 2 is darker (as shown in fig. 2), the enzyme deactivation of the corn cob of the fresh corn food in comparative example 2 is incomplete, because when the enzyme is deactivated by hot water blanching, heat is conducted from corn kernels to the corn cob, after the corn kernels on the surface of the whole corn ear are sufficiently deactivated, the enzyme deactivation of the corn cob in the corn cob cannot be realized sufficiently due to the lower heating temperature, and in contrast, example 1, the corn cob of the fresh corn food in example 1 is lighter (as shown in fig. 1), and the enzyme deactivation is more complete. Therefore, the embodiment of the invention verifies that the material to be deactivated is subjected to microwave enzyme deactivation in a microwave environment after being covered by the flexible protection piece, and the microwave can be used for carrying out key heating aiming at the characteristic of high water content of the corncob, so that the corncob is deactivated more thoroughly, the integral enzyme deactivation effect of the fresh corn food is improved obviously, the shelf life of the fresh corn food is further prolonged, and the good quality of the fresh corn food is ensured to be maintained after the fresh corn food is stored for a long time.

In sterilization, referring to table 1, in example 1, after the flexible protection member is covered by the enzyme-to-be-deactivated material, microwave enzyme deactivation is performed under a microwave environment, and microwave is focused on the characteristic of high water content of corncobs, the central temperature of the corncobs is 90 ℃ before sterilization operation, but in comparative example 2, enzyme is deactivated by hot water blanching, the central temperature of the corncobs is not fully heated, the central temperature of the corncobs is only 25 ℃ before sterilization operation, the difference of the sterilization intensity F ₀ values of the two materials is large after the same sterilization operation treatment, and the sterilization intensity of comparative example 2 is only 3.0min, and in example 1, the microwave enzyme deactivation is performed under the microwave environment after the flexible protection member is covered by the enzyme-to-be-deactivated material, so that the sterilization effect is better, and the product quality can be remarkably improved.

It can be understood that the enzyme deactivation process of comparative example 2 uses hot water to bleach the materials to be deactivated to deactivate enzymes, heat needs to be conducted from corn kernels to corn cobs, the corn cobs are insufficiently heated in the enzyme deactivation process, the central temperature of the corn cobs is lower before the sterilization operation, the sterilization effect is poor, the quality of fresh corn foods is seriously reduced after long-term storage, and in the enzyme deactivation process of comparative example 2, corn is directly contacted with high-temperature bleach water, so that the nutrition and pigment substances of the prepared fresh corn foods are seriously lost (the loss rate of the soluble sugar content is about 38 percent and the VC loss rate is about 50 percent), and the impurity residues such as corn silk and chips in the fresh corn foods are easily caused by only one spray cleaning operation before the enzyme deactivation process of comparative example 2, so that the nutrient substances of the fresh corn foods are seriously lost and the quality is poorer; in the enzyme deactivation process of the embodiment 1, microwave enzyme deactivation is carried out in a microwave environment after the enzyme deactivation material covers the flexible protection piece, the microwave energy is mainly heated according to the characteristic of high water content of the corncob, the corncob is heated sufficiently, so that the enzyme deactivation of the corncob is more thorough, the central temperature of the corncob is higher before the sterilization operation, the integral enzyme deactivation effect and the remarkable sterilization effect of the fresh corn food are improved, the shelf life of the fresh corn food is further prolonged, the fresh corn food is ensured to maintain good quality after being stored for a long time, corn is not in direct contact with high-temperature water in the preparation process of the embodiment 1, the loss of water-soluble nutrient substances such as anthocyanin and the like is effectively reduced, the nutrient components of the fresh corn food are better reserved, and the embodiment 1 can better remove impurities in the fresh corn food by combining the bubbling cleaning operation with the high-pressure cleaning operation, so that the prepared fresh corn food has more excellent quality.

Further, the main difference of comparative example 4 compared with example 1 is that in the enzyme deactivation process of comparative example 4, the material to be deactivated is not covered with the flexible protection member, but is exposed to the microwave environment for microwave enzyme deactivation. Referring to fig. 5, the surface of the fresh corn food in comparative example 4 has the phenomena of dark part of color and white part of color, the corn grain starch in the dark part of color is gelatinized, the corn grain starch in the white part of color is not gelatinized, and the corn grain still has enzyme activity, because the material to be deactivated is exposed to microwave for enzyme deactivation in the microwave environment, the water generated after the material to be deactivated is heated is lost by heat, the material to be deactivated is heated unevenly, and the enzyme deactivation effect is poor, thereby verifying that the material to be deactivated in the embodiment of the invention performs microwave enzyme deactivation in the microwave environment after covering the flexible protection member, and being beneficial to the remarkable improvement of the whole enzyme deactivation effect of the fresh corn food.

It is worth to say that, in the embodiment 1 of the present application, after the enzyme-inactivating material covers the flexible protection member, microwave enzyme inactivation is performed in a microwave environment, and the flexible protection member has better heat preservation and moisture preservation performance, and compared with the protection material with worse heat preservation and moisture preservation performance, or compared with the protection material which is not covered by the protection material in the comparative example 4, the flexible protection member has lower energy consumption and higher product water loss rate and higher production efficiency.

Further, referring to Table 2, compared with example 2, comparative example 1, the anthocyanin content of the fresh corn food prepared in comparative example 1 is 15mg/kg, and the anthocyanin content is lower, because the high-temperature blanching water is directly contacted with corn during blanching and enzyme deactivation, so that anthocyanin in the corn is dissolved in the blanching water, nutrient substances such as anthocyanin and the like of the fresh corn food are seriously lost, in the enzyme deactivation process of example 2, microwave enzyme deactivation is carried out in a microwave environment after the enzyme deactivation material covers the flexible protection member, direct contact with high-temperature water is not needed in the enzyme deactivation process, the loss of water-soluble nutrient substances such as anthocyanin and the like is effectively reduced, and the anthocyanin content of the fresh corn food prepared in example 2 is up to 25mg/kg, and the nutrient substances are better retained.

In addition, compared with example 2, the comparative example 1 has only one spraying cleaning operation before the enzyme deactivation process, which is easy to cause the residues of corn silk, scraps and other impurities in the fresh corn food, while the example 2 can better remove the impurities in the fresh corn food by combining the bubbling cleaning operation with the high-pressure cleaning operation, so that the prepared fresh corn food has more excellent quality.

With continued reference to fig. 3, fig. 4 and table 2, in comparative example 3, compared with example 4, in the enzyme deactivation process of comparative example 3, hot water blanching is adopted to deactivate black corn kernels, and a large amount of anthocyanin of the corns after enzyme deactivation is dissolved in blanching water, so that the blanching water is black (see fig. 3), the anthocyanin content of the prepared fresh corn foods is only 15mg/kg, the anthocyanin loss is serious, and the operations such as color selection, foreign matter detection and the like are not performed after the primary threshing of comparative example 3, the foreign matter risk in the fresh corn foods is high, and meanwhile, the material temperature when the corn kernels enter a quick-freezing tunnel cannot be further reduced only by once normal-temperature water cooling before the secondary freezing operation, so that the energy consumption is increased and the quick-freezing treatment efficiency is reduced; in the enzyme deactivation process of example 4, microwave enzyme deactivation is performed in a microwave environment after the flexible protection member is covered with the enzyme deactivation material, and when the material after the enzyme deactivation process is subjected to the second cooling operation, after the corn kernels are soaked in water at normal temperature, the water at normal temperature is still transparent (refer to fig. 4), anthocyanin is not dissolved in water in a large amount, the anthocyanin content of the prepared fresh corn foods is up to 25mg/kg, nutrients such as anthocyanin are fully reserved, and before enzyme deactivation of example 4, the corn kernels are subjected to the air separation impurity removal operation, the rotary sieving operation and the rotary water washing operation, and the foreign matter detection operation is performed after the enzyme deactivation process, so that the foreign matter impurities of the fresh corn foods can be fully removed, the nutritive value and the quality of the fresh corn foods are improved, and meanwhile, the food safety is effectively ensured.

Therefore, according to the preparation method provided by the embodiment of the invention, the fresh corn is subjected to selective heating enzyme deactivation by utilizing the microwave enzyme deactivation technology, so that the enzyme deactivation effect can be effectively improved, meanwhile, rich nutrients are reserved, the quality of the fresh corn food is obviously improved, and the preparation method has wider application prospect and commercial value.

The technical features described above may be arbitrarily combined. Although not all possible combinations of features are described, any combination of features should be considered to be covered by the description provided that such combinations are not inconsistent.

It should be noted that the above embodiments are merely for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solution described in the above embodiments may be modified or some or all of the technical features may be equivalently replaced, and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present invention.

Claims

1. A preparation method of fresh corn food is characterized by comprising the steps of sequentially carrying out pretreatment, enzyme deactivation and post-treatment on materials to be processed to prepare fresh corn food;

2. The method for preparing a fresh corn food product according to claim 1, wherein the step of inactivating enzyme comprises:

The material to be deactivated is conveyed in a microwave environment after being covered by a flexible protection piece, and the enzyme is deactivated for a first preset time by microwaves;

optionally, the first predetermined time is 1 to 10min, preferably 4 to 10min.

3. The method for preparing fresh corn food according to claim 1 or 2, wherein the step of inactivating enzyme further comprises stopping the microwave treatment of the microwave-inactivated material, and maintaining the temperature for a second predetermined time;

Preferably, the second predetermined time is 0.1-10 min.

4. The method for preparing a fresh corn food according to any one of claims 1 to 3, wherein the flexible protector comprises at least one of teflon high temperature cloth, silicone cloth or polyester film.

5. The method for preparing a fresh corn food according to any one of claims 1 to 4, wherein when the fresh corn food is a quick frozen corn cob or a vacuum packed corn cob, the pretreatment process comprises a bubbling cleaning operation and a high pressure cleaning operation;

optionally, in the bubbling cleaning operation, water immersion type bubbling flushing is adopted;

optionally, in the high-pressure cleaning operation, the material after the bubbling cleaning operation is conveyed by adopting a rolling rod, so that the material is cleaned by high-pressure water in the rolling process.

6. The method for producing a fresh corn food according to any one of claims 1 to 5, wherein when the fresh corn food is a quick frozen corn cob or a vacuum packed corn cob, the post-treatment process comprises a first cooling operation;

Optionally, in the first cooling operation, the material after the enzyme deactivation process is immersed in cooling water for cooling, wherein the temperature of the cooling water is 4-30 ℃, and the cooling time is 2-8 min.

7. The method for producing a fresh corn food according to any one of claim 1 to 6, wherein,

When the fresh corn food is vacuum packed corn cob, the post-treatment process further comprises vacuum packing operation, sterilization operation and foreign matter detection operation, wherein the sterilization temperature is optionally 110-130 ℃, the sterilization time is 18-30 min, the pressure range in the sterilization process is 0.1-0.3 mpa, or

When the fresh corn food is quick-frozen corn cob, the post-treatment process further comprises a first quick freezing operation and a foreign matter detection operation, and optionally, in the first quick freezing operation, the quick freezing temperature is below-30 ℃ and the quick freezing temperature is below-18 ℃ until the center temperature of the material is lower than-18 ℃.

8. The method for producing a fresh corn food according to any one of claims 1 to 7, wherein when the fresh corn food is quick-frozen corn kernels, the pretreatment process comprises a wind separation and impurity removal operation, a rotary sieving operation and a rotary washing operation;

Optionally, in the air separation impurity removal operation, lifting the material to a preset height, and then falling the material, and blowing the material in the falling process;

optionally, in the rotary sieving operation, placing the materials subjected to the winnowing impurity removal operation into a roller sieve for rotary sieving;

Optionally, the rotary washing operation comprises immersing the material after the rotary sieving operation in water, carrying out rotary washing under the disturbance of water flow, and placing the material after the rotary washing on a screen for spray washing.

9. The method according to any one of claims 1 to 8, wherein when the fresh corn food is quick-frozen corn kernels, the post-treatment process comprises a second cooling operation, a distributing operation, a second freezing operation, a selecting operation, a quantitative packaging operation, and a foreign matter detection operation;

Optionally, in the second cooling operation, cooling the material after the enzyme deactivation process by adopting warm water and cold water in sequence, wherein the temperature of the cold water is 4-15 ℃;

Optionally, in the material distribution operation, material is subjected to material distribution treatment under the vibration condition, and the material distribution thickness is smaller than 4cm;

optionally, the selecting operation comprises performing color selection treatment and/or screening classification treatment on the materials after the second freezing operation.

10. The method for producing a fresh corn food according to any one of claim 1 to 9, wherein,

In the second freezing operation, the quick-freezing temperature is below-30 ℃ and the quick-freezing temperature is less than-18 ℃ until the center temperature of the material is lower than-18 ℃;

Optionally, the second freezing operation freezes the material in a quick-freezing tunnel or a quick-freezing warehouse.

11. A fresh corn food product characterized by being prepared by the preparation method according to any one of claims 1 to 10.