CN103834709A - Preparation method and use of low-molecular weight beta-glucan - Google Patents

Abstract

The invention discloses a preparation method and a use of low-molecular weight beta-glucan and belongs to the technical field of food and beverage processing. The preparation method comprises the following steps of preparing an aqueous solution having a mass concentration of 1-5% from marketed food-grade cereal beta-glucan, carrying out treatment by endo-type beta-glucanase for 0.5-4h, controlling viscosity (2%, <100cp) and molecular weight (of 10-100KDa), carrying out decoloring by active carbon, collecting beta-glucan having the molecular weight of 10-100KDa by an ultrafilter membrane, and carrying out freeze drying to obtain a product. The low-molecular weight beta-glucan can be used in foods such as beer and beverages, improves daily intake of beta-glucan, improves human immunity and reduces cholesterol.

Description

A kind of preparation method and application of low molecular weight β-glucan

technical field

The invention relates to a preparation method and application of low-molecular-weight β-glucan, belonging to the technical field of food and beverage processing.

Background technique

The characteristic of β-glucan is the main chain of glucose residues connected by β-1,3 glycosidic bonds, and the side chains of different types are different. For example, thermal gel is completely composed of β-1,3-glucose backbone, scleroglucan, yeast glucan, hydrangea polysaccharide and schizophyllan contain β-1,6-glucosyl side chains, while barley, barley The main chain of β-glucan contained in oats contains β-1,3 and β-1,4-glucosidic bonds in a ratio of about 1:2.4, but there are no branches. At present, β-glucan is used in various industries such as pharmaceuticals, health care products, beauty and skin care products, food additives, and plant vaccines. In medicine, it can assist in the treatment of tumors, lower blood pressure, and lower blood lipids; in health products, it can enhance the body's immunity, regulate endocrine anti-aging, and inhibit the generation of free radicals in the body; in cosmetics, it can protect the appearance, skin care, and anti-aging. ; As a food additive, it can play the role of anti-oxidation and improving texture; in biological pesticides, it can be used as a plant disease-resistant vaccine to improve the disease-resistant ability of crops.

The glucan structure is not the main influence on its activity, and the β-1,3-glycosidic bond is the key to its anti-tumor activity. The β-1,3-glucosyl main chain generally forms a 3-strand helix, which can interact with some targets in the body; while the 3-strand helix is water-insoluble and can be dissociated in alkaline aqueous solution. Most β-glucans have poor water solubility, while only β-glucans (cereal glucans) from oats, barley and barley have good water solubility. Medical research shows that cereal glucan such as oat glucan is a kind of porous soluble fiber, which can regulate human immunity, lower cholesterol, and have the effects of lowering blood pressure, regulating blood sugar and anti-oxidation. According to reports, consumption of at least 3g/day β-glucan has health benefits such as reducing the risk of cardiovascular disease in humans.

The viscosity of β-glucan is very high. Barley β-glucan in beer production will affect the filtration effect of beer. When it is higher than 180mg/L, the stability of finished beer will be affected, and turbidity and precipitation will occur. At present, the content of β-glucan in beer is controlled at 30-90 mg/L, and the yeast-containing beer with highland barley as raw material described in patent ZL201210277111.8 contains 150 mg/L of β-glucan. In addition, the patent ZL201210460834.1 invented a kind of brewed product that mixes crude β-glucan with a content of about 80% and other raw materials, but the product does not purify the β-glucan, and the product will be turbid , higher viscosity.

Contents of the invention

The purpose of the present invention is to provide a preparation method and application of low molecular weight β-glucan, using grain glucan (highland barley glucan, oat glucan and barley glucan) that can be obtained on a large scale as raw materials, Food-grade glucanase is used to catalyze the degradation to obtain a low molecular weight, low viscosity, water-soluble β-glucan.

The technical scheme of the present invention: a method for preparing low molecular weight β-glucan, comprising preparing a 1%-5% aqueous solution of commercially available β-glucan with a content of about 70% to 80% of the grain glucan, Dissolve in a water bath at 70-80°C, then cool to 37-55°C, add commercially available endo-glucanase to treat for 0.5-4h, monitor viscosity (mass concentration 2%, <100cp) and molecular weight (10KDa- 100KDa), add activated carbon for decolorization, remove the activated carbon, collect products with a molecular weight of 10KDa-100KDa with an ultrafiltration membrane, and freeze-dry to obtain the product low molecular weight β-glucan with a purity higher than 95%.

For the raw material of corn glucan with a purity greater than 93%, the activated carbon decolorization step is not required, and other steps are the same.

Cereal β-glucan selection: highland barley β-glucan, oat β-glucan or barley β-glucan. The endo-β-glucanase is selected from endo-β-1,4-glucanase or endo-β-1,3-glucanase.

Low-molecular-weight β-glucan products can be used in beer beverages, and the added concentration in beer is 0.5-6g/L.

The specific steps are:

(1) Prepare low molecular weight β-glucan from 70%-80% pure β-glucan;

Make a 1%-5% aqueous solution of commercially available food-grade grain glucan with a β-glucan content of about 70% to 80%, dissolve it in a water bath at 70-80°C, and then cool it to 37-55°C , add endo-β-glucanase (commercially available) to treat for 0.5-4h, monitor viscosity (2%, <100cp) and molecular weight (10KDa-100KDa), add activated carbon for decolorization, remove activated carbon, and collect with ultrafiltration membrane Products with a molecular weight of 10KDa-100KDa are freeze-dried to obtain low-molecular-weight β-glucans with a purity higher than 95%.

(2) Prepare low-molecular-weight β-glucan from β-glucan with a purity of more than 93%;

Make a 1%-5% aqueous solution of commercially available food-grade, β-glucan content of more than 93% corn glucan, dissolve it in a water bath at 70-80°C, then cool it to 37-55°C, and add Cut β-glucanase (commercially available) for 0.5-4h, monitor viscosity (2%, <100cp) and molecular weight (10KDa-100KDa), use ultrafiltration membrane to collect products with a molecular weight of 10KDa-100KDa, freeze-dry Low molecular weight β-glucan with a purity higher than 95%.

(3) Application of β-glucan in beer beverages

The high-purity β-glucan obtained above is formulated into a 5%-10% solution and added to beer beverages to make the concentration of β-glucan reach 0.5g/L-6 g/L without affecting the clarification of beer beverages degree and taste, and increase the foam holding capacity of beer.

Beneficial effects of the present invention: a simple endo-type β-glucanase treatment method is adopted to reduce the molecular weight of β-glucan, reduce viscosity and improve purity. The obtained low-molecular-weight β-glucan can be added to foods such as beer beverages to increase people's β-glucan intake, and has auxiliary effects on preventing high blood pressure, diabetes and lowering cholesterol.

Detailed ways

Example 1 A preparation method of low molecular weight β-glucan

Prepare a 2% aqueous solution of commercially available food-grade oat β-glucan with a β-glucan content of about 70% (Hangzhou Zhongzhi Kang Mushroom, 70% purity), and dissolve it in a water bath at 70-80°C. Then cool to 37-55°C, add endo-β-glucanase (Genencor, cellulase) to treat for 0.5-4h, monitor viscosity (2%, <100cp) and molecular weight (10KDa-100KDa), add activated carbon Decolorize for 1 hour, filter to remove activated carbon, collect dextran with a molecular weight of 10KDa-100KDa with an ultrafiltration membrane, and freeze-dry to obtain a low molecular weight β-glucan product with a purity of about 95%.

Example 2 A preparation method of low molecular weight β-glucan

Prepare a 2% aqueous solution of commercially available food-grade oat glucan with a β-glucan content of about 98% (Shanghai Wandao, 98% purity), dissolve it in a water bath at 70-80°C, and then cool it to 37 -55°C, add endo-β-glucanase (Genencor, cellulase) to treat for 0.5-4h, monitor viscosity (2%, <100cp) and molecular weight (10KDa-100KDa), and collect molecular weight with ultrafiltration membrane The 10KDa-100KDa glucan is lyophilized to obtain a low molecular weight β-glucan product with a purity of 98%.

Example 3 Application of low molecular weight β-glucan in beer

Prepare high-purity low-molecular-weight β-glucan into a 10% transparent solution, add it to beer (Tsingtao Brewery, wheat concentration 8°P, Shanghai Songjiang), and make the concentration of low-molecular-weight β-glucan in the beer reach 0.5g/ L, 1 g/L, 2 g/L, 4 g/L, 6 g/L, after 15 days of storage at room temperature, it was found that the transparency of the beer remained unchanged, the chroma was in line with the national standard, the beer tasted thick and fragrant, and the beer’s foam holding capacity Increase.

Claims (4)

1. A preparation method for low-molecular-weight β-glucan, characterized in that: commercially available β-glucan content of 70% to 80% corn glucan is made into a 1%-5% aqueous solution, and Dissolve in a water bath at 70-80°C, then cool to 37-55°C, add commercially available endo-β-glucanase to treat for 0.5-4h, monitor the viscosity <100cp and molecular weight of 10KDa-100KDa for the solution with a mass concentration of 2%, Add activated carbon for decolorization, remove the activated carbon, collect products with a molecular weight of 10KDa-100KDa with an ultrafiltration membrane, and freeze-dry to obtain low molecular weight β-glucan with a purity higher than 95%; For the raw material of corn glucan with a purity greater than 93%, the activated carbon decolorization step is not required, and other steps are the same. 2. The preparation method of low molecular weight β-glucan according to claim 1, characterized in that cereal β-glucan is selected from: highland barley β-glucan, oat β-glucan or barley β-glucan sugar. 3. The preparation method of low molecular weight β-glucan according to claim 1, characterized in that endo-β-glucanase is selected from endo-β-1,4-glucanase or endo-β-glucanase. 1,3-Glucanase. 4. the application of the low molecular weight β-glucan prepared by the method according to claim 1 is characterized in that the low molecular weight β-glucan obtained from the degradation of cereal β-glucan is applied to beer, and the high-purity β-glucan is formulated into a 5%-10% solution and added to beer beverages to make the concentration of β-glucan reach 0.5-6 g/L.