What Is the Pectineus?

Pectin is a kind of polysaccharide, and its composition includes two types of homopolysaccharide and heteropolysaccharide. They mostly exist in the cell wall and inner layer of plants, and they are mostly found in the peels of citrus, lemon, grapefruit and so on. White to yellow powder, relative molecular weight is about 20000 ~ 400,000, and tasteless. It is more stable in acidic solution than in alkaline solution. Generally it is divided into high ester pectin and low ester pectin according to its degree of esterification. High ester pectin forms an irreversible gel in the range of soluble sugar content 60% and pH = 2.6 3.4. Part of the methyl ester of low-ester pectin is converted into primary amide, which is not affected by sugar and acid, but it needs to combine with divalent ions such as calcium and magnesium to form a gel. ^[1]

Pectin is a type of heteropolysaccharide that is widely found in the primary wall of plant cells and in the middle layer of cells. French pharmacist Brannot was first extracted from carrots in 1824 and named it "pectin". Pectin is mainly a type of acid heteropolysaccharide composed of D-Galacturonic Acids (D-Gal-A) connected by -1,4-glycosidic bonds. In addition to D-Gal-A, Contains neutral sugars such as L-rhamnose, D-galactose, and D-arabinose, as well as up to 12 kinds of monosaccharides such as D-mannose and L-fucose, but these monosaccharides are in pectin The content is very small. ^[2]

Due to the factors such as the type of raw materials, growth period, harvesting time, storage time and extraction method, the composition and physical and chemical properties of pectin are very different. Therefore, the physical and chemical properties of pectin are determined. Quality judgment is of great significance. The physical and chemical properties of pectin are mainly solubility, degree of esterification (DE), Gal-A content (galacturonic acid), monosaccharide composition, molecular weight (Mw), rheology and coagulation. Pectin characteristics, which determine the application range and economic value of pectin, the three more important parameters to evaluate pectin quality are DE, gelation degree and Gal-A content. ^[2]

Pectin has always been a part of human's natural diet, and it is a safe and non-toxic natural food additive recommended by the Joint FAO / WHO Food Additives Committee. There is no limit on daily addition. Pectin has many functions. For example, if pectin is a natural vegetable colloid, it can be widely used in the food industry as a gelling agent, stabilizer, tissue-forming agent, emulsifier and thickener. This kind of water-soluble dietary fiber has the function of enhancing gastrointestinal motility and promoting nutrient absorption. It has a good curative effect on the prevention and treatment of diarrhea, bowel cancer, diabetes, obesity and other diseases. It is an excellent base for pharmaceutical preparations. Gum is a good heavy metal adsorbent, because the pectin molecular chain can form an "egg box" network structure with high-priced metal ions, making pectin have a good function of adsorbing heavy metals; in addition, fruit Glue has film-forming properties, good water retention, and resistance to radiation. With the deepening of research work, the use of pectin has been continuously developed, its development potential is huge, and it has a broad market prospect. ^[2]

Pectin is found in all higher plants. In the plant cell wall, pectin is mainly covalently combined with cellulose, hemicellulose, lignin, etc. to form the original pectin, which is a structural material of plants and plays a vital role in maintaining the structure and hardness of plants effect. In addition, pectin can regulate cell permeability and pH. Pectin is the highest in plant cell walls. In dicotyledons, it is mainly present in the primary cell wall and the middle sheet of the plant cell wall, accounting for 30% to 35%. At present, the raw materials used to produce commercial pectin are mainly citrus and apple peel residue. In addition, there are a lot of researches on extracting pectin from by-products such as tofu firewood leaves, banana peel, sunflower, sweet potato, and cilantro, but the research on these raw materials is currently limited to basic research in the laboratory. Pectin content in different raw materials varies widely. ^[2]

In Europe and the United States, the main use of pectin is the gelation and thickening of processed fruits, such as beverages, jams, salad dressings, etc .; and Japan and other countries are more used as protein stabilizers for acid milk beverages. ^[6] Pectin is mainly produced by state-owned Denmark, the United Kingdom, the United States, Israel, France, etc. Asian countries have very little output, especially Japan, which consumes about 10% of the world's output, has no manufacturers and relies entirely on imports. In China, because the price of imported pectin is much higher than that of domestic pectin, domestic pectin has become the expectation of many domestic enterprises. Therefore, it is extremely important to vigorously develop China's rich pectin resources and produce high-quality pectin to meet domestic and foreign market demand. urgent. ^[5]

With the improvement of people's living standards and the repeated exposure of food safety incidents, people are paying more and more attention to food safety, and the call for healthy and nutritious food is growing. As a natural food additive, pectin will increasingly replace chemically synthesized or chemically modified non-nutritive or low-nutritive food additives such as sodium carboxymethyl cellulose (CMC-Na) and modified starch. Application in yogurt, beverage, jam, candy, jelly, etc. Therefore, we can see that the pectin market has huge potential, and the market demand for pectin will continue to increase. ^[6]

Studies have also shown that pectin has certain important physiological functions, such as reducing serum cholesterol and blood glucose levels, stimulating phage and macrophages, proliferating spleen cells, anti-complement activity, inhibiting the release of hyaluronidase and histamine, Endotoxin-induced inflammatory response and prevention of cancer occurrence and metastasis. ^[7]