dietary fiber (DF) is generally considered to be a class of compounds that cannot be digested by human digestion enzymes and are mainly composed of edible plant cell wall residues (cellulose, hemicellulose, lignin, etc.) and associated substances. According to its solubility, it can be divided into water-soluble dietary fiber and insoluble dietary fiber.

Common water-soluble dietary fibers are mainly: inulin, glucan, resistant starch, chitosan, oat β-glucan, guar gum, sodium alginate, fungal polysaccharides, etc. Common foods in barley, beans, carrots, citrus, flax, oats and oat bran are rich in water-soluble fiber.

In contrast, water-soluble dietary fiber because of its good processing properties and better physiological functions, in recent years in food processing as a thickener, expansion agent, formulation additives and fillers, widely used in the production and development of low energy food and functional food, water-based dietary fiber related food has a huge space for development, market prospects.

Physicochemical properties and functions of water-soluble dietary fiber

First, high water retention and high expansion and function

There are many hydrophilic genes in the structure of water-soluble dietary fiber, which has strong water absorption, high water retention and high expansion. It can increase the volume of stool and defecation speed, reduce the pressure of rectum and urinary system, relieve the symptoms of urinary system diseases such as cystitis bladder stones and kidney stones, and make toxins quickly excreted from the body, prevent constipation and prevent rectal cancer.

The high water retention and dilatancy of dietary fiber delay gastric emptying, make people's stomach feel full and reduce food intake, which is conducive to preventing obesity and losing weight.

Second, the use and function of adsorption and boiling

There are many active genes on the surface of water-soluble dietary fiber, which can boil and absorb organic molecules such as cholesterol and bile acid, inhibit the increase of total cholesterol concentration, reduce the synthesis and absorption of human cholesterol and salts, and reduce the cholesterol in human serum and liver, so as to prevent coronary atherosclerosis and prevent cardiovascular diseases.

Third, fermentation and adjustment of intestinal microbiota function

Soluble dietary fiber can be fermented into acetic acid, lactic acid and other organic acids by beneficial bacteria in the large intestine, reduce intestinal PH, promote the growth of beneficial bacteria bifidobacterium in the intestine, prevent intestinal mucosa atrophy, and maintain the balance and health of intestinal microbes. The organic acids produced by fermentation can accelerate the peristalsis and digestion of food in the gastrointestinal tract, promote the excretion of feces, prevent the intestinal toxins from stimulating the intestinal wall and the toxins from staying too long, and prevent colon cancer.

4, no energy filling economy and prevention of obesity function

Soluble dietary fiber expands after being bound to water (absorption-holding water), which plays the role of filling economy in the intestine and easily causes satiety. At the same time, dietary fiber also affects the absorption and digestion of available carbohydrates and other components in the intestine, which also makes people less likely to have hunger. So dietary fiber is very beneficial in preventing obesity.

5.Solubility and viscosity and their functions

Soluble food fiber is sticky and has a great influence on food viscosity. Due to the increased viscosity, the contact between intestinal contents and intestinal mucosa is reduced, thus delaying the absorption rate, which can stabilize the blood sugar content of diabetic patients after eating, promote the discharge of insulin from the pancreas, and facilitate the supply and metabolism of sugar. The increase of dietary fiber in food can improve the sensitivity of peripheral tissue to insulin, so as to regulate and control the blood sugar level of diabetic patients.

Application of water-soluble dietary fiber in food

Water-soluble dietary fiber as a new type of dietary fiber and thickening agent, expansion agent, formulation additives, fillers, etc., mainly used in low energy, high fiber and other functional foods. In low-energy foods, water-soluble dietary fiber can partially or completely replace sugar and fat, while reducing food energy, it can maintain the original flavor and texture of food, and bring satisfactory taste. In addition to health products, water-soluble dietary fiber with its good solubility, stability, peaceful taste and other characteristics, in the beverage, dairy products, candy, baking and other food fields have a wide range of applications.

First, the application of water-soluble dietary fiber in health food

1, the application of health food in diabetic people Diabetes is a disease caused by absolute or relative insufficient insulin, manifested by the metabolic disorders of carbohydrates, fats, proteins, water and electrolytes. Water-soluble dietary fiber can delay gastric emptying, form a mucous membrane in the gastrointestinal tract, and slow down the digestion and absorption of food nutrients. In this way, the sugar in the blood can only increase slowly, or the insulin is slightly insufficient, and the blood sugar concentration will not increase immediately.

At the same time, water-soluble dietary fiber also has the effect of inhibiting glucagon secretion. The results showed that after dietary fiber was added to the diet, fasting blood glucose decreased from (9.84 ±3.51) mmol/L to (6.82±2.65) mmol/L, and 2h postprandial blood glucose decreased from (13.08±5.12) mmol/L to 10.57± 4.64 mmol/L, all P < 0.01. Developed products such as: water-soluble dietary fiber softgel, fructan syrup, etc.

2.Application of Water-soluble dietary fiber in health food for people with constipation Water-soluble dietary fiber is currently widely used in health food that regulates microecological balance and moistens bowel laxity. When water-soluble dietary fiber is taken, it promotes beneficial bacteria such as intestinal bifidobacterium and Lactobacillus, and produces a large number of short-chain fatty acids, such as acetic acid, acetic acid, folic acid and lactic acid, which changes intestinal pH and improves the breeding environment of beneficial bacteria. Thus speed up the intestinal peristalsis, so that the stool is discharged smoothly.

The application of water-soluble dietary fiber in dairy products

1, the application of water-soluble dietary fiber in milk powder

Water-soluble dietary fiber is more suitable for adding in milk powder to produce infant formula milk powder and middle-aged and elderly milk powder. The digestive tract function of infants and middle-aged and elderly people is not very good, and it is easy to lack calcium. Water-soluble dietary fiber has the effect of moistening bowel, lowering blood lipids, lowering blood sugar, and promoting the absorption of mineral elements. The addition amount of water-soluble dietary fiber in milk powder is 5% ~ 10%, and the addition method is to add water-soluble dietary fiber before the homogenization of milk concentrate, and other processes remain unchanged; Or add milk powder directly after mixing, stir well.

2, the application of water-soluble dietary fiber in fermented yogurt

Yogurt is one of the fastest growing dairy products, and it is also one of the most popular milk drinks in healthy dairy products. In recent years, high-fiber yogurt products are very popular. The formula design of high-fiber yogurt products is: high-quality fresh milk 80%, whole milk powder 3%, high fructose corn syrup (71%) 3%, sucrose 2%, water 10%, water-soluble dietary fiber 6%, starter culture 2.5%, stabilizer 0.2%.

3, the application of water-soluble dietary fiber in flavored milk beverage Flavored milk beverage has appeared in the domestic and foreign markets for many years, because it has a frankincense flavor, but also with fruit flavor, the fusion of the two flavors makes flavored milk beverage flavor unique, coupled with a certain nutrition, so it is welcomed by the majority of consumers, especially by children and young women welcome. Adding water-soluble dietary fiber to flavored milk drinks can greatly increase the nutrition and health function of milk drinks.

The formula design (taking chocolate flavored milk drink as an example) is: raw milk (milk powder) 80% ~ 90% (9% ~ 12%), high fructose corn syrup (71%) 6% ~ 8%, sucrose 4% ~ 6%, water-soluble dietary fiber 6% ~ 8%, cocoa powder 1% ~ 2%, stabilizer 0.2%, vananthine appropriate amount, flavor appropriate amount, pigment appropriate amount. 4, the application of water-soluble dietary fiber in lactic acid bacteria drinks, also known as fermented acidic milk drinks, usually milk or milk powder, plant protein milk (powder), fruit and vegetable juice, sugar as raw materials, with or without adding food additives and auxiliary materials, after sterilization, cooling, inoculation of lactic acid bacteria starter culture fermentation, An active (non-bactericidal) or inactive (bactericidal) beverage that is then diluted. Although the active bacteria beverage contains a certain amount of beneficial bacteria, there are few beneficial bacteria left after the human digestive tract, and its nutritional health function is greatly reduced. The nutritional and health function of inactive bacterial drinks is extremely limited.

How to improve the nutritional and functional components of lactic acid bacteria beverage is a difficult problem in front of every milk beverage production enterprise. Water-soluble dietary fiber with its superior health care effect for the majority of milk beverage production enterprises to provide a good choice, bring new hope. Formula design: yogurt 30%, high fructose corn syrup (71%) 8%, sucrose 2%, water-soluble dietary fiber 6%, pectin 0.4%, juice (6%) 45%, lactic acid 0.1%, essence 0.1%, water 47.4%.

Third, the application of water-soluble dietary fiber in beverages

Dietary fiber drinks are popular functional drinks in the West. It can quench thirst, replenish water, and provide dietary fiber required by the human body. Such products, especially water-soluble dietary fiber, are more popular in developed countries such as Europe, the United States and Japan. For example, the Japanese Coca-Cola company produces mineral water containing dietary fiber, which is popular in Japan; In addition, high-fiber orange juice and high-fiber tea are also common in Western European countries and the United States; At present, domestic Huiyuan Company has developed and produced high-fiber juice, and Beijing Sanyuan Dairy has launched high-fiber milk.

Long-term drinking can make the intestines comfortable, prevent constipation, and can reduce cholesterol, regulate blood lipids, blood sugar, help lose weight, especially suitable for middle-aged and elderly people, diabetic patients and obese people to drink. Used in beverages, the characteristics are as follows:

1.Drinking drinks with water-soluble dietary fiber can enhance the sense of satiety and reduce the intake of caloric substances while absorbing various nutrients. Long-term drinking can significantly help control weight loss, especially suitable for middle-aged and young obese people.

B, after the use of water-soluble dietary fiber in the beverage, other particles in the beverage can be evenly distributed in the solution, which is not easy to precipitate and stratify.

Fourth, the application in infant food

In infants and young children, especially after weaning, bifidobacteria in the body decrease sharply, resulting in diarrhea anorexia, developmental retardation, and reduced utilization of nutrients. Consumption of water-soluble dietary fiber foods can improve the utilization of nutrients and promote the absorption of trace elements such as calcium, iron and zinc.

Fifth, the application in candy

In the future, the development of the confectionery industry gradually tends to be low sugar and low fat, and it is developing in the direction of both delicious and nutritious. In developed countries, the market share of low-energy confectionery has increased year by year, showing its strong momentum to monopolize the entire confectionery market. Water-soluble dietary fiber, as a major ingredient in low-energy food, is very useful in the confectionery market.

Water-soluble dietary fiber (Polydextrose) can be used in all confectionery formulations to replace glucose syrup, and can be used in conjunction with other alternative sweeteners to replace sucrose.

Application of water-soluble dietary fiber in meat products

By adding water-soluble dietary fiber to meat products, dietary fiber interacts with protein to form heat-stable gel through salt and hydrophobic bond. The complex formed by interaction between soluble dietary fiber and protein is a new type of gel.

In addition, dietary fiber can also absorb scented substances to prevent the volatilization of scented substances. In addition, dietary fiber is also an excellent fat substitute, which can produce ham sausage with health function of high protein, high dietary fiber, low fat, low salt and low calorie.

Seven, water-soluble dietary fiber in the application of flour products

1.Application in bread, steamed bread, rice and noodles

Bread has become a popular food around the world, with a large sales volume. In Europe and the United States, dietary fiber is added to most breads to varying degrees, and some studies have shown that adding different kinds of dietary fiber can also increase and improve bread color. Adding dietary fiber in steamed bread, the general addition amount is 3% to 6% of flour is more appropriate. The addition of dietary fiber can strengthen the strength of the dough, and the steamed bun has a good taste and special flavor.

The addition of rice also has a good taste of fluffy fragrance, and the general addition of dietary fiber to these two staple foods will be beneficial to the health of the masses. In addition to dietary fiber in noodles, the general suitable amount is 3% to 6%. However, the effect of different kinds of fiber is different, and some of the strength of raw noodles is weakened after addition, but the strength is increased after cooking, and the noodles after addition are generally good toughness and cooking resistance. The key to noodle adding technology is to master the amount of added and different types of dietary fiber.

2.Application in cookies and pastries

Biscuit baking has very low requirements on the quality of flour strength, and it is also convenient to add dietary fiber in a large proportion, so it is conducive to the production of a variety of health biscuits based on fiber function. Pastries contain a lot of water during production, which will solidify into soft products and affect the quality when baked. Water-soluble dietary fiber added to the pastry can keep the product soft and moist, increase the shelf life and extend the shelf storage time.

8.Sports food

Dietary fiber has high water retention, relatively small volume, and large volume after water absorption, which has a volume effect on the intestinal tract and produces a sense of satiety, and it can reduce the blood sugar value after intake of dietary fiber, so as to achieve energy slow release. Based on these two characteristics, sports food is made, which is eaten before and after fitness or participation in sports.

Nine, frozen food

Increase the group type and water retention of products. Adding method: According to about 1% of the total amount of sinking material, add 3-5 times the weight of dietary fiber water, and stir well with sinking material.

Ten, in sauce products

Good water absorption and water retention, increase the juice viscosity of the product, improve sensory properties, uniform, no stratification.