CN103844182A - Method for producing non-glutinous rice nutritional instant rice - Google Patents

Abstract

The invention relates to a production method of japonica rice nutritious instant rice, which belongs to the technical field of food processing. The principle of the method of the present invention is based on the conversion of restricted fermentation, the strong absorption of alcohol to moisture and lipids, the cavitation of medium and short-wave infrared rays and microwaves, and the combined drying effect of internal and external uniformity, so as to improve the local flavor, nutritional value, and Rehydration performance and storage performance. The main process steps are: selecting japonica rice, washing, soaking at 20-40°C for 14-18h, steaming for 25-30min, cold showering and separating, filtering and stewing the rice for 15-20min, restrictive fermentation for 12-14h, using infrared rays with a wavelength of 2-4μm Dry to a moisture content of 10-12%, and then use a microwave frequency of 2450±50MHz to dry to a moisture content of 3-4%. The prepared instant rice has good taste, rich nutrition, good rehydration performance and storage property.

Description

A kind of production method of japonica rice nutritious instant rice

technical field

The invention relates to a method for producing japonica rice nutritious instant rice by means of restricted fermentation and infrared-microwave combined drying, which belongs to the technical field of food processing.

Background technique

Instant rice is generally made by soaking rice, gelatinizing it at high temperature, drying and dehydrating quickly, and packaging it. When eating, it is soaked in hot water and eaten with seasoning packets or other side dishes. It is somewhat similar to the instant noodle diet. The production method of relevant instant rice is a lot at present, and what patent literature discloses also has many, but, the biggest defect of the instant rice produced by existing various methods is that mouthfeel is bad, and nutritive value is not high, and rehydration property and storability are relatively poor.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a processing method for Japonica rice instant rice with good taste, strong rehydration property, good storage performance and more nutrition.

After the rice is fermented with rice wine koji, it can not only produce sugars, vitamins and a variety of essential amino acids (such as lysine) that cannot be synthesized by the human body, but also partially degrade starch and protein components, making them easier to absorb. In addition, the alcohol produced during the fermentation process can be converted into alcohol water vapor by heating in an appropriate way. Alcohol water vapor is an amphiphilic molecule, which has a strong absorption effect on small molecule organic matter and moisture (including bound water) in the material. During the escape process of alcohol water vapor, it will increase the pore structure of instant rice and improve the rehydration performance of rice. At the same time, alcohol water vapor will take out bound water and small molecular lipid components in rice during drying, which not only reduces water activity , It can also greatly reduce the failure phenomenon of instant rice.

Infrared rays are rays that have a thermal effect. Medium and short-wave infrared rays have strong penetrating ability, and the drying process can be consistent inside and outside, and has a good cavitation effect. In the drying process, different materials have different absorption wavelengths, and the infrared rays with matching wavelengths are used for treatment, so that the heat transfer process consumes less energy and basically does not change the original color and taste of the product.

Microwaves have wave-particle duality, and can interact with the medium to cause vibration and temperature rise. For example, microwaves with a frequency of 2450 MHz can cause the molecules of the medium to vibrate 2.45 billion times per second, and the molecules of the medium produce friction with each other. The resulting increase in the temperature of the medium makes the inside and outside of the medium material heat up almost simultaneously, forming a body heat source state, which greatly shortens the heat conduction time in conventional heating. Using microwave as a secondary drying method for instant rice can not only produce a large number of pore structures and improve the rice rehydration performance, but also evaporate the residual water and alcohol that may be attached to the inside of the rice grains.

The invention performs restricted fermentation on the steamed japonica rice, improves the taste of the rice, strengthens the nutrient components of the rice, increases the pore structure of the rice, improves the rehydration performance of the rice, reduces the lipid components that affect the storability of the convenient rice, and reduces the water activity. .

The technical solution adopted by the present invention to solve the technical problem is: a production method of japonica rice nutrition instant rice, the japonica rice is washed, soaked, steamed, separated, stewed, restricted fermentation, infrared drying and microwave drying to obtain Japonica rice instant rice with good flavor, high nutritional value, good rehydration and storage properties. Specifically, it is realized through the following steps:

(1) Washing and soaking of rice: remove impurities from japonica rice, wash with tap water for more than 3 times, add 1.3-1.5 times of tap water, soak at 20-40°C for 14-18 hours;

(2) Rice steaming and dispersing: steam the soaked rice grains for 25-30 minutes, and quickly cool them with pure water to prevent the rice grains from sticking together. After filtering, steam the rice for 15-20 minutes, and cool down naturally to 30-32°C;

(3) Fermentation of rice: Dissolve rice wine koji with 2-3×10 ¹⁰ cfu/g of viable cells in purified water at 30-32°C, mix evenly with rice, put it into a clean ceramic container, seal it, and place it at 30- Ferment at 32°C for 7-8 hours, transfer to 22-24°C for 5-6 hours, and rake the rice after fermentation; the amount of rice wine koji added is 3-4g/kg japonica rice, and the amount of pure water added 100-150g/kg japonica rice;

(4) Drying of rice: Dry the raked rice with infrared rays until the moisture content is 13-15%, the wavelength of infrared rays is 2-4μm, the temperature of the heat source is 400-500°C, and the distance between the heat source and the rice is 8-10cm; use microwaves to continue drying to the moisture content 3-4%, the microwave frequency is 2450±50MHz, and the power is 150-180W.

The raw japonica rice used in the present invention needs to be selected and cleaned first. If the non-washed japonica rice is selected, the quality of the final product will be better. From the perspective of industrialized production, the present invention has no special limitation on the varieties and specifications of the raw japonica rice, and the selection of rice and elutriation equipment and operations are common techniques, so they will not be described in detail.

One of the differences between the process of the present invention and the prior art is:

In view of the disadvantages of existing instant rice such as poor taste, low nutritional value, poor rehydration and storage properties, optimize the rice cooking process, adopt restricted fermentation, and quickly convert the produced sugar into alcohol by controlling the degree of saccharification and rapid fermentation , The fermented rice is combined with infrared and microwave drying. Medium and short-wave infrared rays have strong penetrating ability, the drying process can be consistent inside and outside, and has a good cavitation effect, which can promote the formation of pore structure and improve the rice rehydration performance. Microwaves cause the friction of medium molecules to heat up, and evaporate the residual moisture and alcohol that may be adsorbed inside the rice grains. During the drying process, the alcohol and water are heated to produce alcohol water vapor, and in the process of volatilization from the inside out, a large number of pore structures are produced, and the water activity of the rice is reduced at the same time. During the restricted fermentation process, the lipids in rice are degraded under the action of koji and yeast, and the alcohol water vapor will take out small molecular organic matter when it escapes, which can greatly extend the storage period of instant rice. The production process is continuous and compact, infrared and microwave drying complement each other, have a good synergistic effect, and have a significant effect on improving the sensory quality, rehydration performance and storage performance of instant rice.

Detailed ways

The present invention will be further described below in conjunction with embodiment. Determination of rehydration rate: Accurately weigh A g of the finished product of convenient straight rice noodles and place it in a beaker, add 5 times of boiling water and immediately cover and rehydrate for 8 minutes, then drain immediately and dry the surface moisture with filter paper, weigh B g, rehydration rate Expressed with B/A. The shelf index indicates the storage performance of instant rice at 37±2°C and 75±5% humidity, and the higher the index, the longer the shelf life. Comprehensive sensory evaluation: 50 tasters aged 15-60 were asked to score the sensory quality (appearance, smell, taste, hardness and viscosity) of instant rice and calculate the average value, with 1 being the worst and 100 being the best.

Example 1

Weigh 1000 g of japonica rice after removing impurities, wash it with tap water 4 times, add 1500 ml of tap water, soak for 18 hours at 20°C, steam continuously for 30 minutes, and quickly drizzle with pure water to prevent the rice grains from sticking together. After filtering, steam the rice 15 min. The rice is raked and dried with infrared rays until the water content is 3%, the wavelength of infrared rays is 4 μm, the temperature of the heat source is 500 ° C, and the distance between the heat source and the rice is 10 cm. The rehydration rate, shelf index and sensory quality of the obtained instant rice were tested.

Example 2

Weigh 1,000 g of japonica rice after removing impurities, wash it with tap water 4 times, add 1,500 ml of tap water, soak for 18 hours at 20°C, steam for 30 minutes, and quickly cool down with pure water to prevent the rice grains from sticking. After filtering, steam the rice After 15 minutes, the temperature was naturally lowered to 32°C. Dissolve 4 g of Anqi sweet wine koji (living cell content 2-3×10 ¹⁰ cfu/g, material number 83500007) in 150ml of purified water (32°C), mix evenly in the rice, put it into a clean ceramic container, seal it, Ferment for 7 h at 32°C, then transfer to 24°C for 5 h. The fermented rice is harrowed and dried with infrared rays until the water content is 3%, the wavelength of infrared rays is 4 μm, the temperature of the heat source is 500 ° C, and the distance between the heat source and the rice is 10 cm. The rehydration rate, shelf index and sensory quality of the obtained instant rice were tested.

Example 3

Weigh 1,000 g of japonica rice after removing impurities, wash it with tap water 4 times, add 1,500 ml of tap water, soak for 18 hours at 20°C, steam for 30 minutes, and quickly cool down with pure water to prevent the rice grains from sticking. After filtering, steam the rice After 15 minutes, the temperature was naturally lowered to 32°C. Dissolve 4 g of Anqi sweet wine koji (living cell content 2-3×10 ¹⁰ cfu/g, material number 83500007) in 150ml of purified water (32°C), mix evenly in the rice, put it into a clean ceramic container, seal it, Ferment for 7 h at 32°C, then transfer to 24°C for 5 h. The fermented rice is harrowed and dried with infrared rays until the water content is 13%, the infrared wavelength is 4μm, the heat source temperature is 500°C, and the distance between the heat source and the rice is 10cm; then the microwave is used to continue drying until the water content is 3%, and the microwave frequency is 2450±50MHz. The power is 180W. The rehydration rate, shelf index and sensory quality of the obtained instant rice were tested.

Example 4

Select 1,000 g of high-quality japonica rice, wash it with tap water for 3 times, add 1,300 ml of tap water, soak at 40°C for 14 hours, steam continuously for 25 minutes, and quickly cool down with pure water to prevent the rice grains from sticking. After filtering, steam the rice for 20 minutes. Cool down to 30°C. Dissolve 3 g of Anqi Liquor Koji (Material No. 83500007) in 100ml of purified water (30°C) and evenly mix it with rice, put it into a clean ceramic container, seal it, and ferment it at 30°C for 8 hours, then transfer to 22 The fermentation was continued for 6 h at ℃. The fermented rice is harrowed and dried with infrared rays until the water content is 15%, the infrared wavelength is 2μm, the heat source temperature is 400°C, and the distance between the heat source and the rice is 8cm; then the microwave is used to continue drying until the water content is 4%, and the microwave frequency is 2450±50MHz. The power is 150W. The rehydration rate, shelf index and sensory quality of the obtained instant rice were tested.

Table 1 Comparison of Examples and Determination of Physical and Chemical Indexes of Instant Rice

Example shelf index Rehydration rate Comprehensive sensory evaluation (1-100 points) Example 1 19 2.8 79 points Example 2 twenty three 3.2 85 points Example 3 25 3.5 87 points Example 4 25 3.4 87 points

 From Table 1, it can be seen that restricted fermentation of rice can significantly improve the shelf index, rehydration rate and sensory quality of instant rice. Infrared and microwave drying have a synergistic effect, which can improve the quality of instant rice products of japonica rice.

Claims (2)

1. A production method of nutritional and instant polished round-grained rice is characterized by comprising the following steps:

(1) rice washing and soaking: removing impurities from semen oryzae Sativae, elutriating with tap water for more than 3 times, adding 1.3-1.5 times of tap water, soaking at 20-40 deg.C for 14-18 hr;

(2) rice cooking and dispersing: steaming and boiling the soaked rice grains for 25-30 min, quickly spraying purified water to prevent adhesion of rice grains, filtering, steaming for 15-20 min, and naturally cooling to 30-32 deg.C;

(3) rice fermentation: the living cells are containedAmount of 2-3X 10¹⁰ Dissolving cfu/g of rice wine yeast in 30-32 deg.C purified water, mixing uniformly in rice, placing into a clean ceramic container, sealing, fermenting at 30-32 deg.C for 7-8 hr, transferring to 22-24 deg.C, fermenting for 5-6 hr, and raking the rice after fermentation; wherein,

(4) drying the rice: drying the scarified rice by infrared rays until the water content is 13-15%, the wavelength of the infrared rays is 2-4 mu m, the temperature of a heat source is 400-; and continuously drying by adopting microwave until the water content is 3-4%, the microwave frequency is 2450 +/-50 MHz, and the power is 150-.

2. The production method according to claim 1, wherein the koji is added in the step (3) in an amount of 3-4g/kg of japonica rice, and the purified water is added in an amount of 100-150g/kg of japonica rice.