阅读说明：本技术 一种提高即食米饭复水性的方法 (Method for improving rehydration of instant rice ) 是由 佟健 李燕秋 韩小荣 于 2021-03-01 设计创作，主要内容包括：本发明涉及一种即食米饭,具体涉及一种提高即食米饭复水性的方法,其包括以下步骤：将淘洗后的大米按其10～7～10～9cfu/g的接种量接种含有乳酸杆菌、葡萄糖菌的发酵菌剂发酵12～48h后依次经过蒸煮和包装得到即食米饭；发酵剂中乳酸杆菌、葡萄糖菌按有效菌种数比为3～5∶1。本发明通过常温乳酸菌微发酵制备即食米饭,通过发酵过程中内源酶的酶解作用,使大米皮层及化学层结构变松散,显著提升产品的水合能力,进而改善其复水性能。(The invention relates to instant rice, in particular to a method for improving rehydration of the instant rice, which comprises the following steps: washing rice according to the weight ratio of 10 7 ～10 9 Inoculating a fermentation microbial agent containing lactobacillus and glucose bacteria in cfu/g, fermenting for 12-48 h, and sequentially steaming and packaging to obtain instant rice; the ratio of effective strains of lactobacillus and glucose bacteria in the starter is 3-5: 1. The invention prepares the instant rice by the micro-fermentation of the lactobacillus at the normal temperature, and the instant rice is prepared by fermentationThe rice bran layer and chemical layer structure become loose by the enzymolysis of endogenous enzyme in the fermentation process, the hydration capability of the product is obviously improved, and the rehydration performance of the product is improved.)

1. A method for improving the rehydration of instant rice is characterized by comprising the following steps: washing rice according to the weight ratio of 10⁷～10⁹Inoculating a fermentation microbial agent containing lactobacillus and glucose bacteria in cfu/g, fermenting for 12-48 h, and sequentially steaming and packaging to obtain instant rice; the ratio of effective strains of lactobacillus and glucose bacteria in the starter is 3-5: 1.

2. The method for improving rehydration of instant rice according to claim 1, wherein: the fermentation temperature is 20-40 ℃, and the humidity of the fermentation environment is 20-50%.

3. The method for improving the rehydration of instant rice, according to claim 1, further comprising the steps of: soaking the fermented rice in a composite inhibitor for 6-8 h; the composite inhibitor comprises the following components in percentage by weight: 10-30% of tea polyphenol, 10-20% of maltase, 10-20% of beta-lactoglobulin and the balance of water.

4. The method for improving rehydration of instant rice according to claim 3, wherein the fermented rice is mixed and soaked with the compound inhibitor at a volume ratio of 2: 1-2.

5. The method for improving rehydration of instant rice, according to claim 3, wherein: the preparation method of the composite liquid of the tea polyphenol is that the tea polyphenol, CNF powder and water are mixed according to the weight portion ratio of 2:1:5, and the mixture is stirred in an ultrasonic stirrer with the stirring speed of 1500-.

6. The method for improving rehydration of instant rice according to claim 1, wherein the cooking time is 10-40 min and the cooking temperature is 100 ℃.

7. The method for improving the rehydration of instant rice, according to claim 1, further comprising the steps of: and (3) placing the cooked rice into a microwave drying box for microwave treatment for 5-10 min, wherein the microwave power is 320-.

Technical Field

The invention relates to instant rice, in particular to a method for improving rehydration of the instant rice.

Background

The instant rice is also called instant rice, and is a novel instant food which is produced on the basis of modern science and technology and is suitable for fast-paced life needs. At present, the instant rice on the market mainly comprises alpha-cooked rice, frozen rice, canned rice and sterile packaged rice.

Compared with the prior art, the method has the advantages of simple process, low water content (10-15%), easy storage, convenient eating and wide market. However, the alpha-rice needs to be restored by adding water when being eaten, and the water absorption of the rice is poor due to the existence of the rice skin layer and the chemical composition in the process; meanwhile, amylose in the reheated alpha-cooked rice is easy to spontaneously migrate and associate to form recrystallization (namely short-term aging), so that the hardness of the cooked rice is increased, the viscoelasticity of the cooked rice is weakened, and the eating quality of the product is influenced.

The main problems of the alpha-cooked instant rice are as follows: the starch is aged for a short time in the eating process, so that the eating quality of the product is reduced. Amylose molecules are straight-chain structures, have small space barriers in a solution, and are easy to be oriented and associated to form recrystallization.

Disclosure of Invention

Technical problem to be solved

In order to solve the above problems of the prior art, the present invention provides a method for improving rehydration of gelatinized instant rice by alleviating rapid aging of amylose molecules of the gelatinized instant rice.

(II) technical scheme

In order to achieve the purpose, the invention adopts the main technical scheme that:

a method for improving the rehydration of instant rice comprises the following steps: washing rice according to the weight ratio of 10⁷～10⁹Inoculating a fermentation microbial agent containing lactobacillus and glucose bacteria in cfu/g, fermenting for 12-48 h, and sequentially steaming and packaging to obtain instant rice; the ratio of effective strains of lactobacillus and glucose bacteria in the starter is 3-5: 1.

Furthermore, the fermentation temperature is 20-40 ℃, and the humidity of the fermentation environment is 20-50%.

Further, it also includes the following steps: soaking the fermented rice in a composite inhibitor for 6-8 h; the composite inhibitor comprises the following components in percentage by weight: 10-30% of tea polyphenol, 10-20% of maltase, 10-20% of beta-lactoglobulin and the balance of water.

Further, it also includes the following steps: and mixing and soaking the fermented rice and the composite inhibitor according to the volume ratio of 2: 1-2.

Further, the preparation method of the composite liquid with the tea polyphenol being CNF-tea polyphenol comprises the steps of mixing the tea polyphenol, CNF powder and water according to the weight part ratio of 2:1:5, and stirring the mixture in an ultrasonic stirrer with the stirring speed of 1500-1500 r/min and the ultrasonic power of 1000-1500U to prepare the composite liquid.

Furthermore, the cooking time is 10-40 min, and the cooking temperature is 100 ℃.

Further, it also includes the following steps: and (3) placing the cooked rice into a microwave drying box for microwave treatment for 5-10 min, wherein the microwave power is 320-.

(III) advantageous effects

The invention has the beneficial effects that:

according to the invention, the instant rice is prepared by the normal-temperature lactobacillus micro-fermentation technology, the rice cortex and chemical layer structure is loosened through the enzymolysis of endogenous enzymes in the fermentation process, the hydration capability of the product is obviously improved, and the rehydration performance of the product is further improved. In addition, the invention also adopts (tea polyphenol, maltase, beta-lactoglobulin) to promote the formation of amylose-tea polyphenol compound by regulating and controlling the polymerization degree of starch chains in the instant rice and the action mode between the starch chains and polyphenol guest molecules so as to relieve the rapid aging of amylose molecules and improve the product quality.

Detailed Description

For a better understanding of the present invention, reference will now be made in detail to the present invention by way of specific embodiments thereof.

The embodiment provides a method for improving rehydration of instant rice, which comprises the following steps: washing rice by 10 weight parts⁷～10⁹Inoculating cfu/g of a fermentation microbial inoculum containing lactobacillus and glucose bacteria, fermenting for 12-48 h, and sequentially steaming and packaging to obtain instant rice; the ratio of effective strains of lactobacillus and glucose bacteria in the starter is 3-5: 1.

In the embodiment, lactobacillus and glucose bacteria are used as a composite microbial inoculum, and enzymes such as lactic acid, amylase and cellulase generated in the fermentation process are utilized to carry out enzymolysis or acidolysis on rice to influence chemical components of the cortex of the rice, so that the rehydration property is improved, and the result can be obtained only on the corresponding inoculation amount of the rice. In addition, in the present embodiment, another purpose of using a combination of lactobacillus and glucose bacteria is to reduce the pH by lactic acid produced by fermentation of lactobacillus to reduce starch retrogradation and decompose intermediate glucose produced, thereby improving the fermentation efficiency of glucose bacteria; glucose fermentation is the most effective synergistic effect for improving the rehydration of cooked rice compared with the combination of other fermentation bacteria and lactobacillus.

In order to improve the fermentation efficiency, the fermentation temperature is further limited to be 20-40 ℃, and the humidity of the fermentation environment is 20-50%.

In order to improve the starch aging delaying effect after rehydration, the method also comprises the following steps: soaking the fermented rice in a composite inhibitor for 6-8 h; the composite inhibitor comprises the following components in percentage by weight: 10-30% of tea polyphenol, 10-20% of maltase, 10-20% of beta-lactoglobulin and the balance of water.

In the embodiment, the compound inhibitors (tea polyphenol, maltase and beta-lactoglobulin) are added, and the amylose-tea polyphenol compound is promoted to be formed by regulating and controlling the polymerization degree of starch chains in the instant rice and the action mode between the starch chains and polyphenol guest molecules, so that the rapid aging of amylose components in the instant rice is delayed. Wherein the emulsification of beta-lactoglobulin (beta-LG) can promote the compounding of small molecules such as small tea polyphenol and the like and starch, and the soaking mode enables maltase to further decompose and saccharify starch alpha-glucosidase in epidermis into D-glucose, thereby reducing the polymerization degree of amylopectin.

Preferably, the fermented rice and the composite inhibitor are mixed and soaked according to the volume ratio of 2: 1-2.

In order to prevent AGEs from generating and depositing due to Maillard reaction between monosaccharides such as glucose and proteins such as beta-lactoglobulin during cooking and prevent tea polyphenol from generating brown substances and deepening the color of cooked rice due to oxidative decomposition during heating, the tea polyphenol in the added composite inhibitor is CNF-tea polyphenol composite liquid, and the preparation method comprises the steps of mixing tea polyphenol, CNF powder and water according to the weight part ratio of 2:1:5, stirring in an ultrasonic stirrer with the stirring speed of 1500-2000 r/min and the ultrasonic power of 1000-1500U, and preparing the composite solution.

The CNF powder is used as a carrier of tea polyphenol substances to form a cellulose-polyphenol compound, the cellulose-polyphenol compound is applied to the preparation of instant rice, the oxidation of the cellulose-polyphenol compound is blocked by utilizing the stronger interface compatibility characteristic of Cellulose Nanofiber (CNF) and the embedding effect of a large number of hydroxyl groups on the surface, the biological stability and the utilization rate of tea polyphenol can be remarkably improved, and the formed CNF-tea polyphenol-amylose compound has a stronger anti-aging effect.

Furthermore, the cooking time is 10-40 min, and the cooking temperature is 100 ℃.

Further, it also includes the following steps: and (3) placing the cooked rice into a microwave drying box for microwave treatment for 5-10 min, wherein the microwave power is 320-.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Example 1

A method for improving the rehydration of instant rice,

s1 rice elutriation: elutriating rice with clear water for 3 times, and quickly draining;

s2 fermentation:

s21 inoculation: pressing rice 10⁹Inoculating cfu/g with a starter culture to the rice washed in step S1, wherein the starter culture is mainly prepared by mixing lactobacillus and glucose bacteria according to the effective bacteria number of 5: 1;

s22 fermentation: fermenting the inoculated rice for 48h in an environment with the temperature of 30 ℃ and the humidity of 50%;

s3 soaking with a composite inhibitor:

preparation of S31 composite inhibitor:

the prepared composite inhibitor comprises the following components in percentage by weight: 20% of tea polyphenol, 20% of maltase, 20% of beta-lactoglobulin and the balance of water;

s32 soaking: and (4) uniformly mixing the rice fermented in the step S2 and the compound inhibitor according to the volume ratio of 2: 1.5, and soaking at the temperature of 25 ℃ for 8 hours for later use.

S4 cooking: steaming the soaked rice in a steaming machine at 100 deg.C for 40 min.

S5, drying and packaging: placing the cooked rice into a microwave drying oven for microwave treatment for 7min, wherein the microwave power is 1000W; packaging and sealing after microwave to obtain the finished product.

Example 2

A method for improving the rehydration of instant rice,

s1 rice elutriation: elutriating rice with clear water for 3 times, and quickly draining;

s2 fermentation:

s21 inoculation: pressing rice 10⁸Inoculating cfu/g with a starter culture to the rice washed in step S1, wherein the starter culture is mainly prepared by mixing lactobacillus and glucose bacteria according to the effective bacteria number of 3: 1;

s22 fermentation: fermenting the inoculated rice for 13h in an environment with the temperature of 40 ℃ and the humidity of 35%;

s3 soaking with a composite inhibitor:

preparation of S31 composite inhibitor:

the prepared composite inhibitor comprises the following components in percentage by weight: 30% of tea polyphenol, 15% of maltase, 20% of beta-lactoglobulin and the balance of water;

s32 soaking: and (4) uniformly mixing the rice fermented in the step S2 and the composite inhibitor according to the volume ratio of 2: 2, and soaking at the temperature of 25 ℃ for 7h for later use.

S4 cooking: steaming the soaked rice in a steaming machine at 100 deg.C for 10 min.

S5, drying and packaging: placing the cooked rice into a microwave drying oven for microwave treatment for 10min, wherein the microwave power is 500W; packaging and sealing after microwave to obtain the finished product.

Example 3

A method for improving the rehydration of instant rice,

s1 rice elutriation: elutriating rice with clear water for 3 times, and quickly draining;

s2 fermentation:

s21 inoculation: pressing rice 10⁷Inoculating cfu/g with a starter culture to the rice washed in step S1, wherein the starter culture is mainly prepared by mixing lactobacillus and glucose bacteria according to the effective bacteria number of 4: 1;

s22 fermentation: fermenting the inoculated rice for 35h in an environment with the temperature of 20 ℃ and the humidity of 20%;

s3 soaking with a composite inhibitor:

preparation of S31 composite inhibitor:

the prepared composite inhibitor comprises the following components in percentage by weight: 10% of tea polyphenol, 10% of maltase, 15% of beta-lactoglobulin and the balance of water;

s32 soaking: and (4) uniformly mixing the rice fermented in the step (S2) and the composite inhibitor according to the volume ratio of 2:1, and soaking at the temperature of 25 ℃ for 6-8 h for later use.

S4 cooking: steaming the soaked rice in a steaming machine at 100 deg.C for 30 min.

S5, drying and packaging: placing the cooked rice into a microwave drying oven for microwave treatment for 5min, wherein the microwave power is 320W; packaging and sealing after microwave to obtain the finished product.

Example 4

The other points are the same as example 1, except that in step S1, the prepared composite inhibitor comprises the following components in percentage by weight: 10% of CNF-tea polyphenol compound liquid, 10% of maltase, 15% of beta-lactoglobulin and the balance of water; the preparation method comprises mixing tea polyphenols, CNF powder and water at a weight ratio of 2:1:5, and stirring in an ultrasonic stirrer with a stirring speed of 1800 rpm and an ultrasonic power of 1500U to obtain the composite solution.

Experiments show that the instant rice of examples 1-3 of the invention has the aging degree which is obviously higher than that of example 4, and the aging degree of the instant rice of example 1 is lower than that of examples 2 and 3.

Comparative example 1

The other points are the same as example 1: the fermentation treatment of step S2 was not performed.

Comparative example 2

The other points are the same as example 1: the composite inhibitor immersion treatment of step S3 is not performed.

Comparative example 3

The other points are the same as example 1: the fermentation treatment of step S2 is not performed, and the composite inhibitor immersion treatment is not performed.

The instant rice prepared in example 1 of the present invention and comparative examples 1 to 3 were subjected to rehydration time, texture measurement and aging degree measurement, respectively.

Experiment-rehydration time and texture determination

Adding boiled water into the finished product of the instant rice according to the mass ratio of rice to water of 1:5, covering and standing, and starting timing. And randomly taking out 5-10 grains of rice every 1min from 2min, placing the rice on a flat plate, crushing the rice grains until no white hard core appears, and ending timing to obtain the rehydration time.

Determination of the texture characteristics: the Texture of the instant rice was measured using a TA-XT 2i Texture analyzer (Texture Analyser) using TPA mode. Experimental parameters: the speed before measurement is 1.0mm/s, the speed after side is 10mm/s, the compression ratio is 70%, and the induction force: auto-5 g, probe type P75, compressed distance 3 mm. The index is measured.

The results are shown in Table 1.

TABLE 1

From the data in table 1:

the quality purchasing characteristics of example 1 are significantly better than those of comparative examples 1-3, and the rehydration time is significantly less than that of comparative examples 1-3, indicating that: the fermentation treatment and the composite inhibitor soaking treatment can improve the texture property of the instant rice and obviously improve the rehydration property of the instant rice;

the quality purchasing characteristic of the comparative example 2 is obviously superior to that of the comparative examples 1 and 3, and the rehydration time is obviously shorter than that of the comparative examples 1 and 3, which shows that the fermentation treatment can obviously improve the quality structure characteristic of the instant rice and obviously improve the rehydration characteristic thereof.

The quality purchase characteristics and rehydration times of comparative example 1 and comparative example 3 are comparable, indicating that: the effect of the soaking treatment with the composite inhibitor alone on the texture characteristics and rehydration time was limited, and it can be seen from the comparison of the data of example 1 and comparative example 2 that the addition of the composite inhibitor can improve the texture characteristics and rehydration of the fermented instant rice.

Experimental secondary aging degree determination

Measurement of degree of aging: and respectively weighing rice samples of different treatment groups by using a differential thermal scanner, sealing, standing overnight for balancing, and testing. Test parameters, initial temperature: 20 ℃, the termination temperature of 120 ℃, the heating rate of 5 ℃/min and the aging degree expressed by delta H. The measurement results are shown in Table 2.

TABLE 2

As can be derived from the data in table 2,

the aging level of example 1 was significantly lower than comparative examples 1-3, indicating that: the aging degree of the instant rice can be reduced by fermentation treatment and composite inhibitor soaking treatment;

the aging degree of comparative example 1 is significantly lower than that of comparative example 2, and the aging degree of comparative example 2 is significantly lower than that of comparative example 3, indicating that the aging degree can be significantly reduced by the soaking treatment or the fermentation treatment of the composite inhibitor, while the aging degree of the composite inhibitor in comparative example 1 is better than that of comparative example 2 which is only subjected to the fermentation treatment, and the fermentation treatment and the composite inhibitor can exert a synergistic effect to maximize the reduction of the aging degree.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.