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CN-121970862-A - Low-GI instant rice and preparation method of enzyme directional reconstruction thereof

CN121970862ACN 121970862 ACN121970862 ACN 121970862ACN-121970862-A

Abstract

The invention belongs to the technical field of food processing, and discloses a preparation method of low GI instant rice and enzyme directional reconstruction thereof, wherein the preparation method comprises the steps of raw material pretreatment, enzyme directional reconstruction modification, formula compounding, molding drying and curing sterilization; wherein, a complex enzyme system composed of glycogen branching enzyme mutant, alpha-amylase inhibitor and glucosyltransferase is adopted to directionally modify the pretreated rice flour, and after being compounded with low GI coarse cereal powder components, the rice flour is molded into rice grains and is prepared into a finished product through a subsequent process. The invention solves the problems of high GI value, contradiction between taste and instant property of the existing instant rice, and the starch structure is regulated and controlled by enzyme orientation to stably reduce the GI, and the finished product is rice-shaped, has low GI attribute, good instant food and edible taste, balanced nutrition and controllable production cost, is suitable for industrialized batch production, and can meet the main food requirement of people with sugar control.

Inventors

  • YU YUN
  • CHEN YUAN
  • YANG MENGNAN

Assignees

  • 江南米道江苏科技有限公司

Dates

Publication Date
20260505
Application Date
20260225

Claims (10)

  1. 1. The preparation method of the enzyme directional reconstruction of the low GI instant rice is characterized by comprising the following steps: S1, preprocessing a long-shaped rice raw material; S2, performing enzyme-directed reconstruction modification on the pretreated rice flour by adopting a complex enzyme system consisting of a glycogen branching enzyme mutant, an alpha-amylase inhibitor and glucosyltransferase; s3, adding low-GI coarse cereal powder, composite dietary fibers, prebiotics and edible salt into the rice flour slurry modified by the enzyme for formula compounding, pressing the compound slurry into rice grains, vacuum drying, and demoulding to obtain formed instant rice grains; S4, steam curing, cooling and ultraviolet sterilization are sequentially carried out on the formed instant rice particles, and packaging is carried out after sterilization is completed, so that a low GI instant rice finished product is obtained; wherein the enzyme directional reconstruction modification is used for directionally regulating and controlling the starch structure and stably reducing the GI value.
  2. 2. The method for preparing the low GI instant rice by enzyme directional reconstitution according to claim 1, wherein the raw material pretreatment comprises the steps of selecting long-grained nonglutinous rice, removing impurities, cleaning, draining, drying at constant temperature, pulverizing, sieving to obtain rice flour, microwave pretreatment, and cooling to room temperature for standby.
  3. 3. The method for preparing the enzyme-directed reconstitution of the low-GI instant rice according to claim 2, wherein the constant temperature drying temperature is 40-45 ℃, the drying temperature is 12-14% of the water content of the rice flour, the rice flour is crushed and then passes through a 80-100 mesh sieve, the power of the microwave pretreatment is 300-350W, and the pretreatment time is 3-5min.
  4. 4. The method for preparing the enzyme directional reconstruction of the low GI instant rice according to claim 1, wherein the enzyme directional reconstruction modification in the step S2 comprises the steps of adding deionized water into the pretreated rice flour, stirring uniformly, adding the complex enzyme system, regulating the pH value of the system, placing the system in a constant temperature water bath kettle for enzymolysis, stirring intermittently in the enzymolysis process, heating to inactivate the complex enzyme system after the enzymolysis is finished, and cooling to obtain the enzyme modified rice flour slurry.
  5. 5. The method for preparing the enzyme-directed reconstitution of the low-GI instant rice according to claim 4, wherein the mass ratio of the glycogen branching enzyme mutant, the alpha-amylase inhibitor and the glucosyltransferase in the complex enzyme system is 1 (0.8-1.2): 0.5-0.7), and the addition amount of the complex enzyme system is 0.3-0.5% of the mass of the pretreated rice flour.
  6. 6. The method for preparing the low-GI instant rice by enzyme directional reconstitution according to claim 4, wherein the enzymolysis temperature is 50-58 ℃, the pH value is 5.2-5.8, the enzymolysis time is 60-90min, the enzyme inactivation temperature is 90-95 ℃, the heat preservation inactivation time is 10-15min, and the intermittent stirring mode in the enzymolysis process is that stirring is carried out for 5min every 15 min.
  7. 7. The method for preparing the enzyme-directed reconstruction of the low GI instant rice, according to claim 1, wherein the glycogen branching enzyme mutant in the step S2 is a recombinant enzyme prepared by site-directed mutagenesis of genetic engineering, the enzyme activity of the glycogen branching enzyme mutant is not lower than 1200U/mg, the method for preparing the glycogen branching enzyme mutant comprises the steps of constructing a glycogen branching enzyme mutant recombinant expression vector by site-directed mutagenesis with a wild glycogen branching enzyme gene as a template, transforming the recombinant expression vector into a host cell, screening positive clones to obtain a recombinant expression strain, performing induced expression on the recombinant expression strain, and separating and purifying an expression product to obtain the glycogen branching enzyme mutant.
  8. 8. The method for preparing the enzyme-directed reconstitution of the low-GI instant rice according to claim 1, wherein the low-GI coarse cereal flour in the step S3 is prepared by mixing oat flour and buckwheat flour according to the mass ratio of (1.8-2.2): 1, the adding amount is 8-12% of the mass of the rice flour, the composite dietary fiber is prepared by mixing konjak flour and resistant dextrin according to the mass ratio of (0.8-1.2): 1.5, the adding amount is 5.5-7.0% of the mass of the rice flour, the prebiotics are prepared by mixing fructo-oligosaccharide and stachyose according to the mass ratio of (0.8-1.2): 1, the adding amount is 2.0-3.0% of the mass of the rice flour, and the adding amount of the edible salt is 0.1-0.2% of the mass of the rice flour.
  9. 9. The method for preparing the enzyme-directed reconstitution of the low-GI instant rice according to claim 1, wherein the vacuum degree of the vacuum drying in the step S3 is 0.06-0.08MPa, the drying temperature is 55-60 ℃, the drying is carried out until the moisture content of the formed instant rice particles is 10-12%, the pressure of the steam curing is 0.12-0.15MPa, the curing time is 8-10min, the strength of the ultraviolet sterilization is 30-40 mu W/cm < 2 >, and the sterilization time is 15-20min.
  10. 10. The low-GI instant rice is characterized by being prepared by the enzyme directional reconstruction preparation method of any one of claims 1-9, is in a rice grain-shaped forming structure, and has low GI attribute, instant property and edible taste after being subjected to enzyme directional reconstruction modification and formula compounding.

Description

Low-GI instant rice and preparation method of enzyme directional reconstruction thereof Technical Field The invention belongs to the technical field of food processing, and particularly relates to low-GI instant rice and a preparation method for enzyme directional reconstruction thereof. Background Along with the promotion of resident health consciousness, the scale of sugar-control crowd is continuously enlarged, and instant rice with convenience and low GI attribute becomes a research hot spot in the field of food processing. The instant rice is taken as a convenient staple food, and has the core requirements of quick eating, good taste and cooperation of nutrition and health, but the three are difficult to consider in the prior art, and a plurality of problems to be solved urgently exist. The current instant rice is mainly divided into traditional instant rice and improved low GI instant rice, the traditional instant rice adopts a high-temperature curing and hot air drying process, although the instant demand is realized, the starch structure is not reasonably regulated and controlled, the GI value is higher, the problems of hard heart, adhesion and rough taste are easy to occur after rehydration, and the demand of sugar-control crowd can not be met. The improved low-GI instant rice adopts a physical modification process, a chemical modification process or a single enzyme modification process, the physical modification process is difficult to realize stable control of the GI value, harmful substances are easy to remain in the chemical modification process, the single enzyme modification process lacks directionality, the starch branched chain structure cannot be accurately regulated, the fluctuation of the GI value is large, the original characteristic of the starch is easy to damage, and the taste and the instant performance are influenced. In addition, the existing complex enzyme modification technology lacks of targeted enzyme combination, the modification effect is not improved by adopting a specific enzyme mutant, and part of technologies take rice to be made into rice flour as a finished product, so that the edible scene is limited, the consumer acceptance is low, and meanwhile, the production cost is high, so that the industrialized batch production is difficult to realize. Therefore, the development of the preparation method for the low-GI instant rice, which is used for directionally regulating and controlling the starch structure, stably reducing the GI value, taking the quick eating property, the taste and the production cost into consideration, is suitable for industrial production, and has important practical significance and application value. Disclosure of Invention In order to solve the defects in the background art, the invention aims to provide low GI instant rice and a preparation method for enzyme directional reconstruction thereof, which solve the problems of unstable GI value and contradiction between taste and instant property in the prior art. The preparation method comprises four steps of raw material pretreatment, enzyme directional reconstruction modification, formula compounding, molding drying, curing and sterilization, wherein a complex enzyme system consisting of glycogen branching enzyme mutant, alpha-amylase inhibitor and glucosyltransferase is adopted as a core, rice flour is directionally modified, and is molded into rice grains after being compounded, and a finished product is prepared through a subsequent process. The invention can directionally regulate and control the starch structure, stably reduce the GI value, give consideration to both quick eating and edible taste, has balanced nutrition and controllable production cost, is suitable for industrial production, and can meet the main food requirement of people with sugar control. The aim of the invention can be achieved by the following technical scheme: The preparation method of the enzyme directional reconstruction of the low GI instant rice comprises the following steps: S1, preprocessing a long-shaped rice raw material; S2, performing enzyme-directed reconstruction modification on the pretreated rice flour by adopting a complex enzyme system consisting of a glycogen branching enzyme mutant, an alpha-amylase inhibitor and glucosyltransferase; s3, adding low-GI coarse cereal powder, composite dietary fibers, prebiotics and edible salt into the rice flour slurry modified by the enzyme for formula compounding, pressing the compound slurry into rice grains, vacuum drying, and demoulding to obtain formed instant rice grains; S4, steam curing, cooling and ultraviolet sterilization are sequentially carried out on the formed instant rice particles, and packaging is carried out after sterilization is completed, so that a low GI instant rice finished product is obtained; wherein the enzyme directional reconstruction modification is used for directionally regulating and controlling the starch structure and stably reducing