Pectin is a kind of polysaccharide, which consists of homogeneous polysaccharide and impurity polysaccharide. Most of them exist in plant cell walls and cell lining, and a large number of them exist in citrus, lemon, grapefruit and other peels.
White to yellow powder with relative molecular weight of about 20000 ~ 400000, tasteless. It is more stable in acidic solution than in alkaline solution, and is usually divided into high-ester pectin and low-ester pectin according to its esterification degree.
When the soluble sugar content is ≥60% and the pH value is 2.6 ~ 3.4, the high ester pectin forms an irreversible gel. Part of methyl ester of low-ester pectin is converted into primary amide, which is not affected by sugar and acid, and needs to combine with divalent ions such as calcium and magnesium to form gel.
Pectin was introduced as follows:
Pectin is a group of polygalacturonic acids. It is water soluble and can be separated in industry, and its molecular weight is about 50,000 to 300,000. Under suitable conditions, its solution can form gel and be partially methoxylated (methyl ester), and its main component is partially methylated a( 1, 4)-D- polygalacturonic acid. The residual carboxyl units exist in the form of free acids or form salts such as ammonium, potassium, sodium and calcium.
As follows:
Pectin, as a food additive or ingredient, is used in food industry, which mainly plays the roles of gelation, thickening, texture improvement, emulsification and stability.
In the process of yogurt production, different kinds of pectin have different functions. For example, adding high-fat pectin can stabilize the structure of yogurt, and adding low-methoxyl pectin can prevent whey from separating out.
In the process of making yogurt, it is necessary to strictly control the amount of pectin. Once enough additives are not added, the charge will be neutralized, the repulsive force will fade, and the structure of dairy products will not be stable, so we can only continue to add them, and the structure of acidic dairy products will remain stable after generating new repulsive force.
If the pectin content in the raw materials is too small when making jam, then the thickening effect of pectin can be used, and 0.20% pectin can be used as thickener. The amount of pectin in low-sugar jam is about 0.60%. The formula of low-sugar strawberry jam is: strawberry 50.00%, granulated sugar 36.00%, water 13.00%, amidated low methoxyl pectin 0.60% and citric acid 0.40%.