CN101851651B - A kind of biological synthesis method of temperature-resistant dendritic slow-digestion starch - Google Patents

Abstract

The invention discloses a biosynthesis method of temperature-resistant dendritic slow-digesting starch, which belongs to the technical field of non-chemically modified starch. The present invention utilizes the biocatalytic conversion technology of β-amylase, maltose transglucosylase, maltosyl amylase, branched amylase and transglucosidase to convert commercial starch from different sources, such as corn starch, wheat starch, rice starch, Starch, potato starch, tapioca starch, sweet potato starch, mung bean starch, chickpea starch, sorghum starch, sago starch, and canna starch, etc., use a new type of hydrolysis-transglycosidic amylase to modify the recombinant starch molecular chain, so as to obtain a slow Thermotolerant dendritic starch with digestive properties. The temperature-resistant dendritic slow-digesting starch obtained in the present invention can be used as a functional raw material to develop low-glycemic health food, energy slow-release food, carrier material for targeted and controlled release of nutritional factors, and the like.

Description

A kind of biosynthesis method of temperature-resistant dendritic slow-digesting starch

technical field

The invention relates to a method for synthesizing temperature-resistant dendritic slow-digesting starch from natural starch by biological enzyme method, and belongs to the technical field of non-chemically modified starch.

Background technique

With changes in social structure, accelerated pace of life, changes in eating habits and food composition, and aging society, the spectrum of human diseases has undergone great changes. Chronic diseases, such as diabetes, cardiovascular disease, obesity, hyperlipidemia, The increasing proportion of insulin resistance-related diseases such as hypertension has become a major global public health problem. The key to preventing the above-mentioned diseases lies in a scientific and reasonable dietary structure.

Slowly digestible starch (slowly digestible starch, SDS) refers to those starches that are completely digested and absorbed in the small intestine but at a slower rate. According to the classification of starch bioavailability, it can be defined as the nutritional fragment of starch digested by mixed enzymes (pancreatic α-amylase, glucoamylase and invertase) within 20-120 minutes under simulated digestion conditions in vitro. As a new type of functional food, SDS is slowly digested and absorbed after eating, continuously releases energy, maintains postprandial blood sugar homeostasis, and can prevent and treat various diet-related chronic diseases (such as obesity, diabetes, glycogen accumulation disease and Metabolic syndrome), thus increasingly becoming a research hotspot in the field of food science and modern nutrition. At present, the research institutions of SDS are mainly concentrated in European and American countries, and the relevant reports are limited to the research of preparation method and physiological function, and domestic research in this field is rare. Moreover, the SDS preparation method mainly adopts gelatinized starch recrystallization treatment to form physical state SDS, which is prone to transformation under certain processing conditions and has poor thermal stability; the hydrolysis/transglycolation effect of new amylase is used to modify starch molecular chains to synthesize chemical states. Temperature-resistant dendritic SDS, this product can meet the needs of food processing operations and nutrition maintenance, and has broad market application value as a new type of functional food accessories.

Contents of the invention

The object of the present invention is to provide a biosynthesis method of temperature-resistant dendritic slow-digesting starch with high nutritional value, good health care function and low glycemic index.

Technical scheme of the present invention: a biosynthesis method of temperature-resistant dendritic slow-digesting starch, using starch as raw material, using β-amylase, maltose transglucosylase, maltosyl amylase, branched amylase, transglucoside Enzyme biocatalytic transformation technology, through multi-enzyme synergistic hydrolysis-transglycoside modification of recombinant starch molecular chains, so as to obtain temperature-resistant dendritic slow-digesting starch; the process is:

A) Weighing 1 g of raw starch to make a starch milk solution with a mass concentration of 1%-50%, and then cooking at a temperature of 80-100° C. for 2-30 minutes to make it completely gelatinized;

B) After the starch paste is cooled to room temperature, add 10-50mL of pH4.0-7.0 sodium acetate buffer solution and 100-5000U/g substrate mixed enzyme solution, the mixed enzyme solution is selected from β-amylase and maltose transglucosylase , maltosyl amylase, branched amylase, and transglucosidase, optionally composed of two enzymes, the ratio of the two enzymes being a volume ratio of 1:1 to 1:100;

C) at a temperature of 30-90°C and a pH of 4.0-7.0, constant stirring and constant temperature reaction for 1-24h;

D) After the enzyme-inactivating treatment, the sample solution is treated by membrane ultrafiltration with a molecular weight cut-off of 500-1000 Da, and then the obtained product is dried and pulverized to obtain a temperature-resistant dendritic slow-digesting starch.

Utilizing enzyme biocatalytic conversion technology, through multi-enzyme coordinated hydrolysis-transglycoside modification to regulate and design the starch molecular chain structure, and obtain a temperature-resistant dendritic slow-digesting starch with a content of more than 60%.

The raw material starch is corn starch, wheat starch, rice starch, potato starch, tapioca starch, sweet potato starch, mung bean starch, chickpea starch, sorghum starch, sago starch or plantain taro starch.

The branch density of heat-resistant dendritic slow-digesting starch is 10%-40%, and the content of heat-resistant dendritic slow-digesting starch basically does not change after high-temperature cooking.

The application of the temperature-resistant dendritic slow-digesting starch synthesized by the method: it is used as a functional raw material to develop low-glycemic health food, energy slow-release food, nutrient factor targeted and controlled release carrier material, etc.

Above-mentioned cooling, inactivating enzyme, drying, pulverizing etc. are the common technologies in the current food processing field.

The whole starch analysis kit produced by Ireland Megazyme Company was used to measure the content of heat-resistant dendritic slow-digesting starch according to the Englyst method. The SDS content of the obtained product was ≥60%, the branch density was 10%-40%, and the SDS content was basically the same after high-temperature cooking. No change.

The branch density of dendritic starch is expressed by the ratio of α-1,6 glycosidic bonds in the fine structure of the molecular chain, and the peaks with chemical shifts of 5.4ppm and 5.0ppm on the ¹ H NMR spectrum define α-1,4 glycosides respectively number of bonds with α-1,6 glycosidic bonds.

Beneficial effects of the present invention:

1. The raw material of the present invention adopts common cereal starch, potato starch, bean starch and other plant-derived starch in the domestic market, and the raw material has a wide source and is not limited by the place of production and the season.

2. Using starch as raw material, adopting the enzymatic synthesis process of the present invention to effectively increase the content of temperature-resistant and slow-digesting starch, to ensure good product processing performance, high nutritional value, and significantly lower cost; at the same time, the present invention adopts a clean production process, reducing the cost Relatively low, basically no pollution to the environment.

3. The present invention uses novel amylase hydrolysis-transglycoside action to obtain temperature-resistant dendritic slow-digesting starch with a content of more than 60%. The product quality is good, and the SDS basically does not change after high-temperature processing, while the product yield of the prior art is low. , poor thermal stability, difficult to achieve commercialization.

4. The use of the technology of the present invention realizes continuous production, with simple procedures and easy automatic control.

5. The product developed by the present invention releases energy continuously after digestion, can maintain postprandial blood sugar homeostasis, and prevents insulin resistance. Factor-targeted and controlled-release coating materials, etc., have high technological added value, have a broad potential market, and have high social and economic benefits.

specific implementation plan

Example 1

Weigh 1g of waxy cornstarch to prepare a starch milk solution with a concentration of 20%, and then cook it at 80°C for 30 minutes to make it completely gelatinized; when the starch paste is cooled to room temperature, add 26mL of sodium acetate buffer solution with a pH of 5.5 A new type of amylase mixed solution with 1000U/g substrate, wherein the mixed enzyme solution is composed of β-amylase and transglucosidase (volume ratio 1:1); keep stirring and constant temperature reaction at 55°C for 10h; deenzyme treatment Finally, the membrane ultrafiltration treatment with a molecular weight cut-off of 650Da is used, and then the obtained product is dried and crushed to obtain a temperature-resistant dendritic slow-digesting starch. The SDS content is 78% and the branch density is 35%. After high-temperature cooking, the SDS content is basically No change.

Example 2

Weigh 1g of potato starch to prepare a starch milk solution with a concentration of 1%, and then cook it at a temperature of 100°C for 5 minutes to make it completely gelatinized; A new type of amylase mixed solution per gram of substrate, wherein the mixed enzyme solution is composed of branched amylase and maltosyl amylase (volume ratio 1:10); kept stirring at 35°C for 24 hours at a constant temperature; The membrane ultrafiltration treatment with a molecular weight cut-off of 500 Da is adopted, and then the obtained product is dried and pulverized to obtain the temperature-resistant dendritic slow-digesting starch. The SDS content was determined to be 65%, the branch density of the temperature-resistant dendritic slow-digesting starch was 19%, and the content of the temperature-resistant dendritic slow-digesting starch was basically unchanged after high-temperature cooking.

Example 3

Weigh 1g of indica rice starch to prepare a starch milk solution with a concentration of 40%, and then cook it at a temperature of 90°C for 15 minutes to make it completely gelatinized; A new type of amylase mixed solution per gram of substrate, wherein the mixed enzyme solution is composed of maltosyl amylase and maltose glucosylase (volume ratio 1:90); keep stirring at 90°C for 1.5 hours at a constant temperature; inactivate the enzyme After the treatment, the sample liquid is treated with membrane ultrafiltration with a molecular weight cut-off of 1000 Da, and then the obtained product is dried and pulverized to obtain the temperature-resistant dendritic slow-digesting starch. The SDS content was determined to be 71%, the branch density of the temperature-resistant dendritic slow-digesting starch was 24%, and the content of the temperature-resistant dendritic slow-digesting starch was basically unchanged after high-temperature cooking.

Claims (2)

1. A biosynthetic method of temperature-resistant dendritic slow-digesting starch, characterized in that: using starch as raw material, utilizing the biocatalytic conversion technology of branched amylase, transglucosidase, and maltose-transglucosylase, through multi-enzyme Synergistic hydrolysis-transglycoside modification to recombine starch molecular chains to obtain temperature-resistant dendritic slow-digesting starch; the process is: A) Weighing 1 g of raw starch to make a starch milk solution with a mass concentration of 1%-50%, and then cooking at a temperature of 80-100° C. for 2-30 minutes to make it completely gelatinized; B) After the starch paste is cooled to room temperature, add 10-50mL of sodium acetate buffer solution with pH4.0-7.0 and a mixed enzyme solution of 100-5000U/g substrate. The mixed enzyme solution uses branched amylase, transglucosidase, maltose Glucosylase, optionally composed of two enzymes, the ratio of the two enzymes is 1:1 to 1:100 by volume; C) at a temperature of 30-90°C and a pH of 4.0-7.0, constant stirring and constant temperature reaction for 1-24h; D) After the enzyme-inactivating treatment, the sample solution is treated by membrane ultrafiltration with a molecular weight cut-off of 500-1000 Da, and then the obtained product is dried and pulverized to obtain a temperature-resistant dendritic slow-digesting starch. 2. The biosynthesis method of a kind of temperature-resistant dendritic slow-digesting starch according to claim 1, characterized in that: the branch density of temperature-resistant dendritic slow-digesting starch is 10% to 40%, and the temperature-resistant dendritic starch is processed by high-temperature cooking. The content of slowly digestible starch remained basically unchanged.