Pectin is a polysaccharide, its composition has two types of homopolysaccharide and heteropolysaccharide. They are mostly found in the plant cell wall and the inner layer of the cell, a large number of citrus, lemon, grapefruit and other fruit peel. White to yellow powder, odorless. It is more stable in acidic solution than in alkaline solution. It is usually divided into high ester pectin and low ester pectin according to its esterification degree. High ester pectin in the soluble sugar content ≥ 60%, pH = 2.6 ~ 3.4 range of non-reversible gel. Low ester pectin part of the methyl ester is transformed into primary amide, not affected by sugar, acid, but need to be combined with calcium, magnesium and other divalent ions in order to form a gel.
Pectin is a class of heteropolysaccharides widely present in the primary wall of plant cell wall and the cell middle lamellae, in 1824 the French pharmacist first extracted from the carrot, and named it "pectin". Pectin is mainly a class of D-galacturonic acid by α-1,4-glycosidic bond connection composed of acidic heteropolysaccharides, in addition to D-Gal-A, but also contains L-rhamnose, D-galactose, D-arabinose and other neutral sugar, in addition to D-mannose, L-fucose, etc. up to
Pectin is white or yellowish, or grayish, light brown, coarse to fine powder, a few odorless, smooth and sticky texture. Pectin is white or yellowish or grayish, light brown coarse powder to fine powder, almost odorless, viscous and smooth taste. Dissolved in 20 times water, forming a milky white viscous gelatinous solution, weak acidity. Strong heat resistance, almost insoluble in ethanol and other organic solvents. Granulated sugar syrup wet, or mixed with more than 3 times of granulated sugar can improve solubility. Stable in acidic solution than in alkaline solution
Pectin has always been part of the natural human diet and is a safe, non-toxic, natural food additive recommended by the Joint Committee on Food Additives (JCFA), with no daily additive limit. Pectin has many functions, such as pectin as a natural plant colloid, can be used as a gelling agent, stabilizer, tissue-forming agent, emulsifier and thickener widely used in food industry It is an excellent matrix for pharmaceutical preparations; at the same time, pectin is a good adsorbent of heavy metals, this is because pectin's molecular chain can be formed with the high value of metal ions between the "egg carton At the same time, pectin is a good heavy metal adsorbent, because the molecular chains of pectin can form an "egg carton" structure with high-value metal ions, which makes pectin has a good adsorption of heavy metals; in addition, pectin has the characteristics of film-forming, good water-holding properties and radiation resistance