Isomaltooligosaccharide (IMO), also known as branching oligosaccharide (Branchingoligosaccha-ride), refers to a monosaccharide composed of at least one α-1,6 glycosidic bond between glucose, with a number ranging from 2 to 5, which mainly includes: isomaltose, isomaltotriose, panose and isomaltotetraose. Its functional factor is an oligosaccharide bound by α-1,6 glycosidic bond. Because of its low sweetness, anti-crystallization, high sugar boiling temperature, good moisturizing properties and suitable viscosity, it is widely used in candies, beverages, cold drinks, pastries, dairy products, alcohol, and can also be used with other products. Functional health products are combined to develop related health foods.

Physical and chemical properties

(1)The sweetness of isomaltooligosaccharide is 45% to 50% of sucrose, which can reduce the sweetness of food and improve the taste.

(2)The viscosity of isomaltooligosaccharide is higher than sucrose liquid of the same concentration and lower than maltose. It is easier to operate than maltose during food processing and is easier to process. It has no adverse effects on the structure and physical properties of confectionery and pastries.

(3)Isomaltooligosaccharide has excellent heat resistance and acid resistance. It will not decompose even if heated for a long time at pH=3 and 120℃. It is suitable for beverages, cans and foods processed at high temperatures or with low pH values.

(4)In terms of coloring properties, isomaltooligosaccharide can be co-heated with proteins or amino acids to produce Maillard browning reaction. The coloring degree is related to the sugar concentration and is affected by the type of co-heated protein or amino acids, pH value, heating temperature and time.

(5)Isomaltooligosaccharide has good moisturizing properties and good water retention, preventing the aging of starchy foods and the precipitation of sugar crystals.

(6)The water activity of isomaltooligosaccharide (Aw=0.75) is lower than that of sucrose (Aw=0.85) and maltose (Aw=0.77), and general bacteria, yeasts, and molds cannot grow in an environment with Aw ≤ 0.8. This shows that isomaltooligosaccharide has better preservative effect.

(7) Isomaltooligosaccharide cannot be utilized by yeast and lactic acid bacteria. At the same time, it promotes the development of bifidobacteria, but does not affect the normal fermentation of lactobacilli and other bacteria. Its non-fermentation property is the prerequisite for its health-care functions in food.

(8)Isomalto-oligosaccharide is not susceptible to streptococci, and teeth are not easily corroded. When used together with sucrose, it can strongly inhibit the production of glucan from sucrose. The panose in isomaltooligosaccharide has a very obvious effect on hindering the formation of tartar.

Preparation

1.There are three ways to prepare isomaltooligosaccharide:

The first one uses starch as raw material and is obtained through liquefaction, saccharification, transglycoside, separation and purification. This method is also the method used in most industrial production.

The second method directly uses monosaccharides or sucrose as raw materials and converts and polymerizes them through specific transglycosidases. This method has high specificity and can synthesize oligosaccharides containing only α-1,6-glycosidic bonds, but the cost of raw materials and enzymes is relatively high, making it unsuitable for industrial production.

The third method is to use Aspergillus niger or recombinant yeast instead of glucose transsidase for fermentation, using corn steep liquor or maltose syrup as the main component of the culture medium to generate isomaltooligosaccharide. Using starch as raw material, it can be made into isomaltooligosaccharide syrup or powdered sugar through slurrying → liquefaction → saccharification → decolorization → ionization → transglycoside → decolorization → ionization → concentration → spray drying. After the starch is liquefied and saccharified, it is converted into maltose syrup containing a small amount of oligosaccharides, and then a specific transylase is used to synthesize isomaltooligosaccharide containing α-1,6-glycosidic bonds. The patent also focuses on protecting the decolorization and cross-fertilization processes before transglycolysis, because these two steps can remove impurities such as proteins in the saccharification solution and reduce the ionic strength to avoid affecting the effect of transglycoside enzymes. The decolorization and decolonization process after transglycolysis is also to remove proteins, impurities and ions in the syrup to ensure the sensory quality and physical and chemical indicators of the final product. The above process is a common process for preparing IMO-50. To prepare IMO-90 or higher purity isomaltooligosaccharide, it is necessary to remove non-oligomeric isomaltose contained in IMO-50 through chromatographic separation, membrane filtration or yeast fermentation. The components of isomaltose are mainly glucose and maltose.

2. Enzyme catalysis and separation and purification are the key steps in the preparation of high-purity isomaltooligosaccharide.

(1)Enzyme catalysis link The enzyme catalysis link is the key link in the production of oligomaltolsaccharides, and α-glucosidase is the most critical enzyme in the production process. In recent years, research on this link at home and abroad has mainly focused on the following aspects:

The first is to improve the conversion efficiency of α-glucosidase or screen strains with high α-glucosidase production;The second is to conduct enzyme immobilization and cell immobilization research to achieve continuous production. Among microorganisms, bacteria, yeast, and mold can all produce α-glucosidase, among which Aspergillus niger has the highest enzyme activity . Therefore, many studies at home and abroad have used mutagenesis and genetic engineering to improve the expression and secretion of Aspergillus niger glucosidase.

(2) The separation and purification process focuses on separating and removing glucose, maltose and other non-IMO oligosaccharides in IMO-50 type isomaltooligosaccharides to improve the purity of IMO. There are three commonly used methods: yeast fermentation consumption, chromatographic separation and purification, and membrane filtration concentration.

a. Yeast has different utilization and consumption rates for different carbon sources. Isomaltooligosaccharides are generally not used by yeast, while glucose and maltose are good carbon sources for yeast.

b. Chromatographic separation technology is a relatively mature technology suitable for industrial production. It uses the different migration speeds of the substances to be separated in the separation medium to achieve the separation of different components. It is currently widely used in the fields of food, medicine, water treatment, etc.: For example, preparative chromatography has been widely used in the separation of chiral drugs in the medical field, large-scale continuous ion exchange equipment is used for water treatment, and large-scale simulated moving bed preparative chromatography is used for the separation of fructose and glucose. Similarly, this technology can also be used for the separation of functional sugars.

c. Membrane technology is a method that uses natural or artificially synthesized organic or inorganic membranes to separate, classify, purify or enrich multi-component solutions using external energy or chemical potential differences as the driving force. Including reverse osmosis, ultrafiltration, microfiltration, nanofiltration, electrodialysis, membrane electrolysis, diffusion dialysis, dialysis, etc., which are widely used in the separation and purification process of functional sugars, such as maltitol, erythritol, and isomaltooligosaccharide.

Pharmacological effects

1.It can promote the significant proliferation of bifidobacteria. Isomalto-oligosaccharide will not be absorbed by the human stomach and small intestine, but directly enters the large intestine, where it is preferentially used by Bifidobacterium, helping it to multiply in large quantities, and serves as a proliferation factor for Bifidobacterium; other harmful bacteria in the intestine cannot use it, thus it can inhibit the growth of harmful bacteria and promote the adjustment of the microecology in the intestine to a virtuous cycle.

(1)Maintains the balance of normal intestinal bacterial flora, especially in the elderly and infants. Bifidobacterium can inhibit the growth of pathogenic bacteria and putrefactive bacteria and prevent constipation, diarrhea and gastrointestinal disorders.

(2)Bifidobacteria have anti-tumor activity.

(3)Bifidobacterium can synthesize vitamin B 1. B 2. B6, K, niacin, folic acid, etc. in the intestine. It can also biosynthesize certain amino acids, which can improve the body's absorption of calcium ions.

(4)Reduce blood cholesterol levels and prevent and treat high blood pressure.

(5)It can improve the digestibility of dairy products and improve people's tolerance to lactose. Malto-oligosaccharides are added to many dairy products abroad to improve their health care functions.

(6)Enhance human immune function and prevent various adverse side effects of antibiotics on the human body.

2. It has anti-caries properties. Isomaltooligosaccharide is a difficult-to-ferment sugar and will not be used by tooth decay bacteria. When isomaltose with isomaltose residues is used in combination with sucrose, it will strongly inhibit the synthesis of insoluble glucan, thereby preventing the formation of dental plaque and preventing tooth decay bacteria from attaching, growing and multiplying on teeth. Therefore, isomaltose plays an anti-caries role in foods with sucrose as raw material.

3. It is difficult to ferment. Isomaltooligosaccharide is a sugar that cannot be used by yeast and lactic acid bacteria. Adding it to food will not increase the caloric value of the food too much, so consumers do not have to worry about gaining weight .

4. IMO-900 products. Containing more than 45% isomaltose, panose, and isomaltotriose, and more than 90% non-fermentable sugars, it is used in foods suitable for diabetics. It will not increase blood sugar or blood insulin levels after consumption, and its health performance is better than IMO-500, so it has a wider range of applications.

Physiological functions

1.Direct physiological effects

(1)It is difficult to be digested by gastric enzymes, has low sweetness and calories, and basically does not increase blood sugar and blood lipids;

(2) It can promote the proliferation of bifidobacteria in the human intestine, inhibit the formation of harmful bacteria and corrupt substances in the intestine, increase the content of vitamins, and improve the body's immunity;

(3) It has the function of preventing tooth decay. It is not used by the streptococci that cause tooth decay, nor is it broken down by oral enzymes, thus preventing tooth decay.

(4) It belongs to the class of non-digestible oligosaccharides and can function as a water-soluble dietary fiber.

2. Indirect physiological effects

(1) Promote food digestion and absorption and maintain normal intestinal function;

(2) Restoring normal intestinal flora during antibiotic therapy, radiotherapy, and chemotherapy;

(3) Improve diarrhea and constipation, and inhibit pathogenic bacteria and putrefactive bacteria;

(4) Improve the body's immunity and act as an immunomodulator;

(5) Reduce intestinal carcinogens, improve serum lipids, and lower cholesterol levels;

(6) It increases the absorption of minerals such as calcium and magnesium, which is beneficial for the body to synthesize B vitamins .

Application

1.Application in food

(1)Application in dairy products

Infant milk powder: After stopping breast milk, infants will experience diarrhea, constipation, indigestion and other symptoms, all due to the reduction of bifidobacteria in the intestine. In order to restore the health of infants during this period, bifidobacteria factors should be supplemented and the microecology should be adjusted in time. Add isomalt oligosaccharide to infant formula milk powder instead of sucrose, and produce weaning milk powder through spray drying.

Adult milk powder: Adding isomaltooligosaccharide to milk powder can proliferate the bifidobacteria that are increasingly decreasing in the intestines of middle-aged and elderly people, thereby moisturizing the intestines and promoting bowel movements, and enhancing the body's immunity.

Active yogurt: Add isomaltooligosaccharide syrup to fresh milk, and produce active yogurt through bifidobacteria and lactic acid fermentation. Isomaltooligosaccharide plays a key role in ensuring the number and survival of bifidobacteria in yogurt. Or use isomaltooligosaccharide with soy milk to produce functional soy milk, which will have the same effect.

(2)Develop functional juices using fresh fruit resources. Pears from Hebei, kiwis from Shaanxi, coconuts from Hainan, guava from Guangdong, mangoes from Guangxi, apples from Shandong, green plums and bayberries from Jiangsu, and citrus fruits from Zhejiang can all be used to develop a new generation of beverages using oligosaccharides. The heat and acid resistance of oligosaccharides is better than that of sucrose, the water activity is lower than that of sucrose, and the viscosity is similar to that of sucrose. Therefore, it is not necessary to change the process and equipment to replace or partially replace sucrose with oligosaccharides, because it contains bifidus factors and can be called a functional food.

(3)The honey syrup is produced by mixing isomaltooligosaccharide syrup and honey (isomaltooligosaccharide syrup: honey = 1:3) and refining. This product not only improves the appearance quality, but also plays a very important role in preventing and treating constipation, adjusting microecology, and promoting intestinal function.

(4)Utilize local Chinese medicinal materials and isomaltooligosaccharide to produce health-care products with unique functions. For example, develop health-care products with scientific formulas such as hawthorn, yam, and black sesame to moisten the intestines and relieve constipation, and produce health-care products with snow lotus from Xinjiang, cordyceps from Qinghai, or edible fungi developed in various places, which not only improve the taste but also complement each other in function.

(5)The candies produced by the confectionery industry using isomaltooligosaccharide will not cause tooth decay or make the eaters fat.

1)High-grade candies are produced by combining isomaltooligosaccharide with condensed milk, cream, gelatin, spices, etc. Each candy is adjusted to contain more than 2g of isomaltooligosaccharide, making it a health candy with low caloric value, no tooth decay and intestinal regulating effects.

2)Isomaltooligosaccharide is used in combination with fondant, condensed milk, cream, emulsifier, spices, nuts, etc. to produce caramel-flavored candies or aerated candies, which have the functions of preventing tooth decay and regulating the intestines.

3)By using isomaltooligosaccharide syrup and powdered sugar together with gelatin, oil and spices, etc., and utilizing existing equipment, we can produce chewing gum, bubble gum and other health candies that are tooth-proof, low in calories and have intestinal regulating functions, and have an excellent taste.

2.Brewing industry application

Isomaltooligosaccharide can improve the quality of wine and improve the taste. It is usually used in blending fruit wine, grape wine and liquor. Isomaltooligosaccharide is used in the brewing process of rice wine and beer. Glucose and maltose are fermented into ethanol by yeast. Non-fermentable sugars such as isomaltose, panose, isomaltotriose and isomaltotetraose remain in the wine. These non-fermentable sugars improve the taste, especially giving the wine physiological functions.

3.Application in bakery industry, bread and pastry industry

Isomaltooligosaccharide, with its moisturizing, low sweetness and non-fermented sugar function, can make cakes soft and crisp, bread elastic, sweet and delicious, not easy to age, extend the shelf life, and improve the quality grade. It can be used instead of sucrose in the processing of bean paste and lotus seed paste to prevent sand return, caking, not easy to deteriorate, and reduce the sweetness. Long-term use of these foods is beneficial to health .

4.Application in feed processing industry

Oligosaccharides are used in the feed industry instead of live bacteria preparations, and are used in livestock, poultry and aquaculture as animal production promoters and health care agents. Compared with the control group, piglets fed with feed containing 0.25% oligosaccharides for 21 days had a 7% increase in daily weight gain and a 14% decrease in feed conversion rate (meat-to-feed ratio). When broilers are fed with 0.2% oligosaccharides from an early age, their developmental survival rate, meat production rate and feed return rate are all improved.

5.Application in other fields

A mixture of isomaltooligosaccharide and yield-increasing bacteria (various Bacillus cereus) is used in the field of plant protection to increase crop yields. Isomaltooligosaccharide's high purity (more than 98%) products are used in some special treatment situations such as fluid food for critically ill patients, and have good clinical effects in treating hemorrhoids, skin infections, antiviral and antifungal, etc. Synbiotics (Swtiotics) can be made by using isomaltooligosaccharide and live bacterial preparations. The moisturizing and hygroscopic properties of isomaltooligosaccharide can be used in cosmetics and other applications, which has broad development potential.