Production and application of multi-functional soybean dietary fiber

1. Physiological function of Multifunctional Soybean Dietary Fiber

Soybean dietary fiber mainly refers to those macromolecular sugars that can not be digested by human digestive enzymes, including cellulose, pectin, xylan and mannose. Although dietary fiber can not provide any nutrients for the human body, it has important physiological functions for the human body. Dietary fiber can significantly reduce blood pressure and plasma cholesterol, regulate gastrointestinal function, blood glucose and insulin levels. The main components of multi-functional soybean dietary fiber (MuhifunctionalSoy-beanFiber,MSF) are dietary fiber and protein, with a content of 67.98% (dry base) and 19.75% respectively, so it is a good protein-fiber additive. The results show that the addition of a small amount of MSF has a good strengthening effect on medium-gluten or low-gluten flour, and in a certain range, it can not only increase the content of dietary fiber and protein, but also improve the quality of bread, noodles and biscuits. MSF may be the most functional of all dietary fiber, far from other synthetic fibers (such as voxel, polyglucose). Multi-functional soybean dietary fiber is a high-quality dietary fiber obtained from fresh soybean dregs through special heat treatment. it has a good effect in regulating blood sugar, reducing blood lipids and promoting defecation.

two。 Production process of Multi-functional Soybean Dietary Fiber

Wet soybean dregs → acidified (1mol/L hydrogen chloride adjusted to pH 3: 5) → hot water soaked (80 ℃ ~ 100 ℃, 2h) → neutralized (1mol/L sodium hydroxide adjusted pH value to neutral) → dehydration drying (65 ℃ ~ 70 ℃ drying or air drying until moisture content is 8%) → crushed → sifted (80 mesh) → soybean dregs → extrusion (feed moisture 16.8%) 150℃ screw speed 150r/min) → cooling → crushing → function activation and ultra-fine pulverization → MSF.

3. Operation points of preparing Multi-functional Soybean Dietary Fiber

(1) the deodorization process of wet-heat treatment includes acid adjustment, heat treatment and neutralization of soybean dregs. ① adjusts acid. Soak the bean dregs in water and adjust the pH value to 3-5 with 1mol/L hydrochloric acid solution. Because heating treatment under acidic conditions is beneficial to remove the peculiar smell of soybean dregs, and adding acid can also leach some pigment substances and improve the color of the products. ② heat treatment. When the soaked bean dregs were heated to 80 ℃ ~ 100 ℃, the soaked bean dregs were treated with wet heat for about 2 hours to inactivate lipoxygenase, reduce the fishy smell and passivate the anti-nutritional factors. ③ neutralization. The pH value of the mixture was adjusted to neutral with the NaOH solution of 1mol/L.

(2) Extrusion cooking is an important process in the production of high quality and multi-function soybean fiber powder. Extrusion cooking has the following functions: ① can increase the content of soluble dietary fiber. During extrusion cooking of soybean dregs powder, under various strong forces, some hemicellulose (such as arabinoxylan) and insoluble pectin will melt or break part of the connection bond, which will be transformed into a water-soluble polymer, so that the content of soluble fiber will be increased to 10%-16%, which not only meets the requirements of balanced dietary fiber, but also, more importantly, water-insoluble dietary fiber promotes intestinal peristalsis. On the other hand, water-soluble dietary fiber plays a more important role in the physiological metabolism of human body. Therefore, the increase of the content of water-soluble dietary fiber is beneficial to increase the functional properties of the product. ② can improve the physicochemical properties of soybean fiber. Extrusion cooking treatment changed the degree of polymerization, relative molecular weight, monosaccharide composition and relative content of various polymer components in soybean fiber. The increase of the content of water-soluble dietary fiber can improve some physicochemical properties of soybean fiber powder (such as water retention, ion exchange capacity and gel properties, etc.). Because the components of water-soluble polymers are gel polysaccharides, which can form a certain viscoelastic three-dimensional network structure, which is similar to the network structure of gluten, it can improve the rheological properties of gluten and become an improver for flour quality. it improves its application value in food. ③ can reduce the negative effect of phytic acid on the absorption of trace mineral elements. Extrusion can reduce the chelation of phytic acid with metal ions, improve the effect of soybean dregs powder on the absorption of trace elements, improve the exchange capacity of dietary fiber and cations, and improve the function of the product. ④ can improve the quality of products. In the process of extrusion cooking, through the action of heat, the anti-nutritional factors in soybean dregs can be further eliminated, lipase can be killed, and the protein in soybean dregs can be denatured moderately, so as to improve the flavor and storage performance of the products, and facilitate the digestion and absorption of the body.

(3) ultrafine comminution and functional activation are the key steps in the preparation of highly active multi-functional dietary fiber, including the optimization and reorganization of the internal components of the fiber, and the encapsulation of some groups of the fiber. it can avoid the combination of these groups with mineral elements and affect the balance of mineral metabolism of the human body. Only the activated dietary fiber is the real physiologically active substance and can be used in functional food. Dietary fiber without activation treatment can only belong to low energy fillers. ① ultrafine comminution. The smaller the particle size of the final product is, the larger the specific surface area is, and the water holding capacity and expansibility of dietary fiber also increase correspondingly. At the same time, it can also reduce the rough taste characteristics. Therefore, when the bean dregs powder after extrusion cooking is dried to 6%-8% water, ultra-fine grinding should be carried out to expand the specific surface area of the fiber. ② function activation. Due to the active hydroxyl groups on the surface of dietary fiber, it will combine with some mineral elements, which may affect the metabolism of minerals in the body. If the proper wall material is used for encapsulation, this problem can be solved, that is, functional activation can be completed. The aqueous solution prepared by hydrophilic colloid (such as carrageenan) and glycerol can be used as wall material to form fiber microcapsules by spray drying, which can give people a smooth and suitable feeling after import and improve the edible use. In addition, the multi-functional soybean fiber can also be strengthened by mineral elements.

4. Application of Soybean Dietary Fiber in Food

Soybean dietary fiber is widely used in food. as a food additive, soybean dietary fiber can be used in meat products, bread, biscuits, pastries, noodles and sauce. it can also be used in frozen food and stuffing, various beverages and ice cream and health products. The addition of soybean fiber can not only improve the tissue structure and enhance the unique flavor of the product, but also give the product good nutritional properties. The following introduces a production process of dietary fiber-rich biscuits for the elderly.

(1) Special biscuit powder 46.6%, multi-functional soybean fiber 11.7%, shortening 7.3%, high fructose 3.5%, sucrose 7.3%, brown sugar 2%, honey 3.2%, sodium bicarbonate 0.9%, ammonium bicarbonate 0.8%, salt 0.9%, water 11.6%.

(2) the shortening and honey were poured into a horizontal mixer and stirred evenly, then sucrose, brown sugar, high fructose syrup, salt and water, pre-dissolved ammonium bicarbonate solution and sodium bicarbonate solution were added, and then flour and soybean fiber were added to stir 10min until the dough was ripe. Knead the dough at a temperature of 492.52 ℃, then bake 6min in a belt oven after molding in the mold.

Through the experiment, if the addition amount of multi-functional soybean fiber is less than 12%, replacing biscuit special powder has no effect on biscuit quality, and other food additives should be added to increase the addition amount.

With the improvement of people's living standards and the enhancement of health awareness, the demand for health functional food is becoming stronger and stronger. Multi-functional soybean dietary fiber is widely valued and welcomed by researchers and consumers because of its high quality and low price, multiple physiological functions and quality improvement, and there is great potential to develop soybean dietary fiber food market.