CN115843860A - Preservative for preserving cold-eaten rabbits, preparation method and preservation method - Google Patents

Abstract

The invention provides a fresh-keeping agent for cold-eating rabbits, a preparation method and a fresh-keeping method, relate to the technical field of food preservation, and comprise the following components in parts by weight: 5-10 parts of bamboo leaf concentrate; modified chitosan 2-8 parts of sugar; 1-6 parts of lemon juice; 1-8 parts of Houttuynia cordata extract; 1-5 parts of ε-polylysine; 1-3 parts of water.

Description

A kind of fresh-keeping agent, preparation method and fresh-keeping method for cold-eating rabbits

technical field

The invention relates to the technical field of food preservation, in particular to a fresh-keeping agent and a fresh-keeping method for cold-eating rabbits.

Background technique

As a local specialty in Zigong, cold-eating rabbit is called "cold-eating" because it is ruddy in color, spicy and delicious, full of fragrance and long aftertaste. It is generally eaten at room temperature, so it is called "cold-eating". , and then mix it with other auxiliary materials and let it cool down. It is usually stored for 4 days. Cold-eating rabbits are very popular, but their short shelf life is a major obstacle hindering their development.

In the prior art, in order to prolong the shelf life, people usually add preservatives and the like to it, but such substances are more harmful to people's bodies and are not healthy.

Contents of the invention

The purpose of the present invention is to provide a fresh-keeping agent and fresh-keeping method for cold-eating rabbits, so as to achieve the technical effect of extending the shelf life of cold-eating rabbits.

The present invention is realized through the following technical solutions:

Comprising the following ingredients, in parts by weight:

5-10 parts of bamboo leaf concentrate; 2-8 parts of modified chitosan; 1-6 parts of lemon juice;

Houttuynia cordata extract 1-8 parts; ε-polylysine 1-5 parts; water 1-3 parts.

In order to better realize the present invention, further,

Comprising the following ingredients, in parts by weight:

6 parts of bamboo leaf concentrate; 5 parts of modified chitosan; 4 parts of lemon juice;

Houttuynia cordata extract 5 parts; ε-polylysine 2 parts; water 2 parts.

In order to better realize the present invention, further,

The preparation steps of described bamboo leaf concentrate:

Wash the freshly picked bamboo leaves, and wash them with deionized water for 2-5 times, put the bamboo leaves in a vacuum drying box to remove the moisture on the surface, grind them with a pulverizer, and sieve them to obtain the bamboo leaf powder to dry;

Add ethanol to the dried bamboo leaf powder for soaking, the soaking time is 30-60 minutes, then ultrasonic for 20-40 minutes, take the liquid, and filter it, and use a reduced-pressure rotary evaporator to obtain the filtrate at a temperature of 30-45°C Evaporation and concentration are carried out under the conditions to obtain the concentrated solution of bamboo leaves.

In order to better realize the present invention, further,

The preparation steps of described bamboo leaf concentrate:

Wash the freshly picked bamboo leaves, and wash them with deionized water for 3 times, put the bamboo leaves in a vacuum drying box to remove the moisture on the surface, grind them with a pulverizer, sieve, and dry the obtained bamboo leaf powder ;

Add ethanol to the dried bamboo leaf powder for soaking, soaking time is 40 minutes, then ultrasonic for 30 minutes, take the liquid, and filter, the obtained filtrate is evaporated and concentrated with a reduced pressure rotary evaporator at a temperature of 40°C, Obtain bamboo leaf concentrate.

In order to better realize the present invention, further,

The preparation steps of described modified chitosan:

Ultrasonic dispersion of nano-silica and water, during the ultrasonic dispersion process, 1-5 drops of hydrochloric acid are added dropwise at intervals of 10s, after dispersion, dispersed nano-silica is obtained;

Add chitosan to acetic acid to dissolve, the dissolution time is 10-30min, and filter it, add dispersed nano-silica to the filtrate, stir and mix, heat it up to 45-60°C, the heating time The heating time is 10-15 seconds, the temperature is raised and heated for 10-30 minutes, and then the temperature is lowered, and the freeze-drying is performed, and the temperature is lowered for 5-10 seconds to obtain the modified chitosan.

In order to better realize the present invention, further,

The preparation steps of described modified chitosan:

Ultrasonic dispersion of nano-silica and water, 4 drops of hydrochloric acid every 10s during the ultrasonic dispersion process, after dispersion, to obtain dispersed nano-silica;

Add chitosan to acetic acid to dissolve, the dissolution time is 15 minutes, and filter it, add dispersed nano-silica to the filtrate, stir and mix, heat it up to 50°C, and the heating time is 12 seconds, The temperature was raised and heated for 20 minutes, and then the temperature was lowered for freeze-drying, and the temperature was lowered for 6 seconds to obtain the modified chitosan.

In order to better realize the present invention, further,

The method includes the following steps: fully mixing the modified chitosan, ε-polylysine and water, ultrasonically dispersing at 2-8°C, and adding a chelating agent during the dispersing process to obtain a suspension;

The bamboo leaf concentrate, the lemon juice and the houttuynia cordata extract are mixed with water to obtain a mixed liquid.

In order to better realize the present invention, further,

The method comprises the following steps: fully mixing the modified chitosan, ε-polylysine and water, ultrasonically dispersing at 5 DEG C, and adding a chelating agent during the dispersing process to obtain a suspension.

In order to better realize the present invention, further,

It includes the following steps: soak the cold-eating rabbit in the mixed solution for 15 seconds, then air-dry it, add water to the mixed solution, and stir evenly, spray the mixed solution on the surface of the air-dried cold-eating rabbit, and place it under temperature after spraying. Store at 2-5°C for 30-60 minutes, vacuumize and pack into bags.

Detailed ways

The technical solutions in the present invention will be described below in conjunction with the experimental examples in the present invention.

The invention provides a fresh-keeping agent for cold-eating rabbits. In the prior art, the shelf life of cold-eating rabbits is relatively short. In order to prolong the shelf life, preservatives are usually added to it. Such operations will endanger health. In order to solve the above Technical problem, the present invention realizes the purpose of prolonging the shelf life of cold-eating rabbits through the following schemes.

The invention provides a fresh-keeping agent for cold-eating rabbits. The fresh-keeping agent mainly includes the following ingredients in parts by weight:

5-10 parts of bamboo leaf concentrate; 2-8 parts of modified chitosan; 1-6 parts of lemon juice;

Houttuynia cordata extract 1-8 parts; ε-polylysine 1-5 parts; water 1-3 parts.

Cold-eating rabbits are eaten at room temperature without heating. They contain a lot of protein, low fat, low cholesterol, and low calories. Because they contain a lot of protein, and protein is the essential and main nutrient for the reproduction of pathogenic microorganisms, The reduction of pathogenic microorganisms can effectively prevent the deterioration of food, so as to further achieve the purpose of improving and extending the shelf life.

The antistaling agent provided by the present invention contains a mixture of bamboo leaf concentrate, lemon juice and Houttuynia cordata extract, which is used as the first line of defense for cold-eating rabbits. The main principle is to eat rabbit meat cold When processed into cold-eating rabbits, additives are added, such as monosodium glutamate, salt, spices, cooking wine and other seasonings. The addition of these substances changes the cell structure of the original rabbit meat, making the internal structure of the rabbit meat larger. The change of ion K, Na etc. inside the cell enters the internal environment. The bamboo leaf concentrate, lemon juice and Houttuynia cordata extract provided by the invention are combined into a mixed solution and added to cold-eating rabbits to make it possible to create a stable internal environment. The pressure is equal, and there is no ion inside the cell to enter the internal environment, and then break the internal environment. During the storage process, the action of microbial protease, protein, lipid, etc. will be decomposed into a large number of small molecules, resulting in a large number of ions. The presence of liquid prevents a large number of ions from entering the interior of the cells, thereby reducing the speed of cell deterioration, thereby achieving the effect of initially increasing the shelf life.

In addition, there is also a suspension formed by the combination of modified chitosan and ε-polylysine. The surface of modified chitosan has a large space gap, which enables it to incorporate ε-polylysine Amino acid is adsorbed on its surface. Chitosan itself has anti-corrosion and anti-bacterial effects. Combined with natural microbial ε-polylysine, it can resist the invasion of the external environment. Because it is a modified chitosan The surface has a large space, and more ε-polylysine can be adsorbed. During the storage process, it will be released slowly, so as to achieve the effect of optimizing and extending the shelf life.

The present invention strengthens the shelf life of cold-eating rabbits through the combined use of the mixed liquid and the mixed county liquid, which has been shown in long-term test structures and has obtained better experimental feedback.

The specific usage method is as follows:

Soak cold-eating rabbits in the mixture for 15 seconds, then air-dry them, dilute the mixed solution with water, and stir evenly, spray the mixture on the surface of the air-dried cold-eating rabbits, and place it at a temperature of 2-5°C after spraying Store for 30-60 minutes.

In the process of making the above, the preparation of the corresponding ingredients is further refined,

The preparation steps of described bamboo leaf concentrate:

Wash the freshly picked bamboo leaves, and wash them again with deionized water for 2-5 times, put the bamboo leaves in a vacuum drying box to remove the moisture on the surface, crush them with a pulverizer, and sieve them to obtain the bamboo leaves The leaf powder is dried;

Add ethanol to the dried bamboo leaf powder for soaking, the soaking time is 30-60 minutes, then ultrasonic for 20-40 minutes, take the liquid, and filter it, and use a reduced-pressure rotary evaporator to obtain the filtrate at a temperature of 30-45°C Evaporation and concentration are carried out under the conditions to obtain the concentrated solution of bamboo leaves.

The preparation steps of described modified chitosan:

Ultrasonic dispersion of nano silicon dioxide and water, during the process of ultrasonic dispersion, 1-5 drops of hydrochloric acid are added dropwise at intervals of 10s, after dispersion, dispersed nano silicon dioxide is obtained;

Add chitosan to acetic acid to dissolve, the dissolution time is 10-30min, and filter it, add dispersed nano-silica to the filtrate, stir and mix, heat it up to 45-60°C, the heating time The heating time is 10-15 seconds, the temperature is raised and heated for 10-30 minutes, and then the temperature is lowered, and the freeze-drying is performed, and the temperature is lowered for 5-10 seconds to obtain the modified chitosan. Preparation of Houttuynia cordata extract:

Houttuynia cordata is washed, air-dried, added and boiled for 1-3 hours to obtain a boiled liquid, and the obtained boiled liquid is added with ethanol for extraction to obtain a Houttuynia cordata extract.

Example 1:

The antistaling agent for cold-eating rabbits includes the following components, in parts by weight:

6 parts of bamboo leaf concentrate; 5 parts of modified chitosan; 4 parts of lemon juice;

Houttuynia cordata extract 5 parts; ε-polylysine 2 parts; water 2 parts.

The preparation steps of wherein said bamboo leaf concentrate:

Wash the freshly picked bamboo leaves, and wash them with deionized water for 3 times, put the bamboo leaves in a vacuum drying box to remove the moisture on the surface, grind them with a pulverizer, and sieve them to obtain the bamboo leaf powder to dry;

Add ethanol to the dried bamboo leaf powder for soaking, soaking time is 40 minutes, then ultrasonic for 30 minutes, take the liquid, and filter, the obtained filtrate is evaporated and concentrated with a reduced pressure rotary evaporator at a temperature of 40°C, Obtain bamboo leaf concentrate.

Wherein the preparation steps of modified chitosan:

Ultrasonic dispersion of nano-silica and water, 4 drops of hydrochloric acid every 10s during the ultrasonic dispersion process, after dispersion, to obtain dispersed nano-silica;

Add chitosan to acetic acid to dissolve, the dissolution time is 15 minutes, and filter it, add dispersed nano-silica to the filtrate, stir and mix, heat it up to 50°C, and the heating time is 12 seconds, The temperature was raised and heated for 20 minutes, and then the temperature was lowered for freeze-drying, and the temperature was lowered for 6 seconds to obtain the modified chitosan.

The preparation method of preservative:

The modified chitosan, ε-polylysine and water are fully mixed, ultrasonically dispersed at 5°C, and a chelating agent is added during the dispersion process to obtain a suspension;

The bamboo leaf concentrate, the lemon juice and the houttuynia cordata extract are mixed with water to obtain a mixed liquid.

Use the following methods to preserve the freshness of cold-eating rabbits:

Soak cold-eating rabbits in the mixture for 15 seconds, then air-dry them, dilute the mixed solution with water, and stir evenly, spray the mixture on the surface of the air-dried cold-eating rabbits, and place it at a temperature of 2-5°C after spraying Store it for 30-60 minutes, vacuumize it, and pack it into bags.

Comparative example:

Conventionally produced cold-eating rabbits are vacuum-packed without fresh-keeping treatment.

Experimental example:

The above-mentioned cold-eating rabbits are stored at normal low temperature, and the storage temperature is 3°C. The cold-eating rabbits of the embodiment and the comparative example are respectively measured once a day for pH value, conductivity value, absorbance and sensory evaluation, and the measurement time is the first day, respectively. Day 3, Day 7, Day 10, Day 14.

Experimental example 1——PH value measurement

Use of PHS-3E precision pH meter:

Calibration: Prepare standard buffer solutions, respectively pH 4.00, pH 6.86, and pH 9.18. Positioning and calibration: Wipe clean the electrode and filter paper rinsed with distillation, insert it into pH 6.86, wait until the reading is stable, press the positioning button to confirm, adjust the value to 6.86, press confirm after it is stable, and the positioning calibration is completed. Slope calibration: After positioning and calibration, rinse the electrode with distilled water, then wipe it dry and insert it into the standard buffer solution with pH 4.00. After the reading is stable, press the slope to confirm, adjust up and down according to the value displayed on the screen, and finally adjust the value to 4.00. After stabilization Press OK, and adjust the first slope rate up and down according to the value displayed on the screen, and finally adjust the value to 4.00, press OK after stabilization, and the first slope rate calibration to operate. After calibration, there is no need to repeat calibration within 24 hours without shutting down the machine.

Before measurement: weigh 2 g of cold-eating rabbits, wash them 1-2 times, crush them and add 20ml of ultra-pure water to soak for about 15 minutes, filter and leave the filtrate, and use a pH meter to measure the pH value of the cold-eating rabbit filtrate.

Experimental Example 2——Determination of Conductivity Value

Portable conductivity meter, calibrated with potassium chloride solution. First, set the electrode parameters according to the value on the electrode, that is, the electrode constant is 1.004us/cm; then set the temperature coefficient for final calibration, put the electrode into 0.01mol/L potassium chloride standard solution, display the reading, and then set it to SEL. 3. TED is displayed on the screen. At this time, the conductivity value can be adjusted to 1274us/cm. The conductivity value corresponding to the 0.01mol/L potassium chloride standard solution is 1274us/cm. Press the "OK" button.

Before measurement: weigh 2 g of cold-eating rabbits, wash them 1-2 times, crush them and add 20ml of ultra-pure water to soak for about 15 minutes, filter and leave the filtrate, and use a pH meter to measure the pH value of the cold-eating rabbit filtrate.

Experimental Example 3 - Determination of Absorbance

The absorbance was measured by colorimetry, and the absorbance was used to reflect the value of 2-thiobarbituric acid. The national standard method GB/T35252-2017 directly determines the value of 2-thiobarbituric acid in animal fats [1, using malondialdehyde, the product of oil peroxidation, to condense with 2-thiobarbituric acid to produce a color reaction. It is a reddish-brown condensate with a maximum absorption peak at a wavelength of 530nm, and its absorbance is measured.

Weigh fresh cold-eating rabbits (1 ± 0.1) g, wash off the surface grease and additives, stir up and add 10 mL of n-J alcohol to soak for about 30 minutes. Prepare 2-thiobarbituric acid, weigh 0.2g of 2-thiobarbituric acid, dissolve it in a 100mL volumetric flask with n-butanol, let it stand at room temperature to dissolve for about 12-15h, filter with filter paper, and leave the filtrate Then dilute to the mark with n-butanol. Filter the soaking solution of cold-eating rabbits, keep the filtrate, pipette 5mL of the filtrate into the colorimetric tube, then add 5mL of the prepared 2-thiobarbituric acid, and mix well. Boil it in water at 95°C for about 2 hours, and it turns reddish-brown. Then take it out and put it in cold water to cool. After cooling, it is ready to be tested. Measure its absorbance at a wavelength of 530nm under a preheated 723C visible spectrophotometer.

Experimental Example 4 - Sensory Judgment

Refer to the sensory evaluation and summary scoring standards of GB2726--2016; score the color, smell, and shape.

The experimental results are as follows:

PH value test results:

Day 1 3rd day day 7 the 10th day 14 Example 5.6 5.2 4.3 3.8 3.5 comparative example 5.8 5.2 4.5 4.0 3.8

As can be seen from the results,

During the storage of cold-eating rabbits, glycogen and adenosine triphosphate are enzymatically hydrolyzed to produce lactic acid and other calculations, resulting in a decrease in pH value and an increase in acidity, while the pH value of the comparative example without preservatives is always higher than that of the experimental example, indicating that adding Preservatives can prolong the shelf life of cold-eating rabbits.

The test results of conductivity are as follows: Conductivity value (us/cm)

Day 1 3rd day day 7 the 10th day 14 Example 1230 1280 1340 1370 1398 comparative example 1500 1670 1785 1850 1975

During the storage of cold-eating rabbits, the longer the storage time, the more decomposition products, the stronger the conductivity, and the higher the conductivity value will be. As shown in the table, the comparison ratio is getting higher and higher. conductivity, and the experimental example reduces the probability of microbes entering the protein through the preservation of the mixed solution and the mixed solution, thereby achieving a certain biological barrier, thereby reducing decomposition and oxidation, thereby achieving the purpose of freshness, thus proving this. The antistaling agent provided by the invention has the advantage of delaying deterioration.

The absorbance test results are as follows:

Day 1 3rd day day 7 the 10th day 14 Example 0.43 0.42 0.38 0.40 0.43 comparative example 0.65 0.32 0.30 0.35 0.30

The absorbance can reflect the change of the value of 2-thiobarbituric acid. The absorbance measured by the colorimetric method decreases first and then increases, and the absorbance value of the comparative example decreases the fastest. This may be because the fat is produced by the peroxidation reaction Dialdehyde degrades in cold-eating rabbits in a weakly acidic environment, and in this example, the change in absorbance value is small with the increase of time, which further reflects that the deterioration rate of cold-eating rabbits is slow compared to the comparative example.

The sensory test results are as follows:

color

Day 1 3rd day day 7 the 10th day 14 Example 8 7.5 7.0 6.5 5 comparative example 7 5 4.5 3 2

odor

Day 1 3rd day day 7 the 10th day 14 Example 5 4.8 4.5 4.2 5 comparative example 4 3.4 3.0 2.5 2.3

form

Day 1 3rd day day 7 the 10th day 14 Example 5.5 5.2 4.8 4.4 4.1 comparative example 5 4.1 3.3 2.6 2.1

It can be seen from the above sensory aspects that the cold-eating rabbit provided by the present invention is obviously better than the comparative example in sensory, thereby further proving that the fresh-keeping agent provided by the present invention can further prolong the shelf life of the cold-eating rabbit.

To sum up, conventionally, cold-eating rabbits without preservatives can be stored on the shelf for up to 7 days. Generally, the first three days are relatively fresh, and large areas of deterioration will occur later. The antistaling agent can optimize the internal environment of cold-eating rabbits from the inside to the outside, and can resist the invasion of external microorganisms, and keep fresh from the inside to the outside. It can be drawn from the data of the above-mentioned experimental examples that the fresh-keeping effect of the present invention is obviously better than comparative example.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (10)

1. a preservative for cold-eating rabbit fresh-keeping, characterized in that, Comprising the following ingredients, in parts by weight: 5-10 parts of bamboo leaf concentrate; 2-8 parts of modified chitosan; 1-6 parts of lemon juice; Houttuynia cordata extract 1-8 parts; ε-polylysine 1-5 parts; water 1-3 parts. 2. the fresh-keeping agent for cold-eating rabbit fresh-keeping according to claim 1, is characterized in that, Comprising the following ingredients, in parts by weight: 6 parts of bamboo leaf concentrate; 5 parts of modified chitosan; 4 parts of lemon juice; Houttuynia cordata extract 5 parts; ε-polylysine 2 parts; water 2 parts. 3. the antistaling agent for cold-eating rabbit fresh-keeping according to claim 1 or 2, characterized in that, The preparation steps of described bamboo leaf concentrate: Wash the freshly picked bamboo leaves, and wash them with deionized water for 2-5 times, put the bamboo leaves in a vacuum drying box to remove the moisture on the surface, grind them with a pulverizer, and sieve them to obtain the bamboo leaf powder to dry; Add ethanol to the dried bamboo leaf powder for soaking, the soaking time is 30-60 minutes, then ultrasonic for 20-40 minutes, take the liquid, and filter it, and use a reduced-pressure rotary evaporator to obtain the filtrate at a temperature of 30-45°C Evaporation and concentration are carried out under the conditions to obtain the concentrated solution of bamboo leaves. 4. the fresh-keeping agent for cold-eating rabbit fresh-keeping according to claim 3, is characterized in that, The preparation steps of described bamboo leaf concentrate: Wash the freshly picked bamboo leaves, and wash them with deionized water for 3 times, put the bamboo leaves in a vacuum drying box to remove the moisture on the surface, grind them with a pulverizer, sieve, and dry the obtained bamboo leaf powder ; Add ethanol to the dried bamboo leaf powder for soaking, soaking time is 40 minutes, then ultrasonic for 30 minutes, take the liquid, and filter, the obtained filtrate is evaporated and concentrated with a reduced pressure rotary evaporator at a temperature of 40°C, Obtain bamboo leaf concentrate. 5. the fresh-keeping agent for cold-eating rabbit fresh-keeping according to claim 4, is characterized in that, The preparation steps of described modified chitosan: Ultrasonic dispersion of nano-silica and water, during the ultrasonic dispersion process, 1-5 drops of hydrochloric acid are added dropwise at intervals of 10s, after dispersion, dispersed nano-silica is obtained; Add chitosan to acetic acid to dissolve, the dissolution time is 10-30min, and filter it, add dispersed nano-silica to the filtrate, stir and mix, heat it up to 45-60°C, the heating time The heating time is 10-15 seconds, the temperature is raised and heated for 10-30 minutes, and then the temperature is lowered, and the freeze-drying is performed, and the temperature is lowered for 5-10 seconds to obtain the modified chitosan. 6. the fresh-keeping agent for cold-eating rabbit fresh-keeping according to claim 5, is characterized in that, The preparation steps of described modified chitosan: Ultrasonic dispersion of nano-silica and water, 4 drops of hydrochloric acid every 10s during the ultrasonic dispersion process, after dispersion, to obtain dispersed nano-silica; Add chitosan to acetic acid to dissolve, the dissolution time is 15 minutes, and filter it, add dispersed nano-silica to the filtrate, stir and mix, heat it up to 50°C, and the heating time is 12 seconds, The temperature was raised and heated for 20 minutes, and then the temperature was lowered for freeze-drying, and the temperature was lowered for 6 seconds to obtain the modified chitosan. 7. according to claim 6, is used for the preparation method of the antistaling agent of cold-eating rabbit fresh-keeping, it is characterized in that, The method includes the following steps: fully mixing the modified chitosan, ε-polylysine and water, ultrasonically dispersing at 2-8°C, and adding a chelating agent during the dispersing process to obtain a suspension; The bamboo leaf concentrate, the lemon juice and the houttuynia cordata extract are mixed with water to obtain a mixed liquid. 8. preparation method according to claim 7, is characterized in that, The method comprises the following steps: fully mixing the modified chitosan, ε-polylysine and water, ultrasonically dispersing at 5 DEG C, and adding a chelating agent during the dispersing process to obtain a suspension. 9. the fresh-keeping agent for cold-eating rabbits prepared according to the fresh-keeping method described in claim 7 or 8. 10. the fresh-keeping method that is used for the fresh-keeping agent of cold-eating rabbit fresh-keeping according to claim 9, is characterized in that, It includes the following steps: soak the cold-eating rabbit in the mixed solution for 15 seconds, then air-dry it, add water to the mixed solution, and stir evenly, spray the mixed solution on the surface of the air-dried cold-eating rabbit, and place it under temperature after spraying. Store at 2-5°C for 30-60 minutes, vacuumize and pack into bags.