Difference between high ester pectin and low ester pectin

A.

Pectin is a class of polygalacturonic acid polysaccharides whose galacturonic acid residues tend to be esterified by a number of groups, such as methoxy and amide groups. The degree of esterification, also known as methoxylation, refers to the sum of the proportions of methylation, acetylation and amidation in pectin.

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.
Pectin with DE higher than 50% is usually called high ester pectin, and vice versa is called low ester pectin (including amidated pectin, degree of amidation >25%).

High ester pectins form non-reversible gels in the range of ≥60% soluble sugars and pH = 2.6 to 3.4. Low ester pectin partly methyl ester transformed to primary amide, unaffected by sugar and acid, but need to be combined with divalent ions such as calcium and magnesium to form gels.

Q.

Application Difficulty Example: Lactobacillus beverage is unstable

Description: To produce a concentrated lactic acid bacteria drink, the original formula is to add soybean polysaccharide as a stabilizer, and I heard that pectin will taste more refreshing after adding it, but after trying it, the result is even more unstable, and it will be delaminated very quickly.

A.

Reference Directions:
1) Relative to high ester pectin, low ester pectin removes part of the methoxy group, it is a little more sensitive to some metal ions (such as mineral ions in milk), so it is more likely to form insoluble matter when mixed with dairy products. At the same time, low ester pectin is not resistant to fermentation, after fermentation, the organization of the state is also worse, so dairy products are generally used in high-fat pectin.

2) Charge conflict flocculation problem
Soybean polysaccharide is mainly soy protein processing or tofu, bean curd and other soybean products processing by-products of soybean residue fiber as the main raw material, refined by pretreatment, enzymatic digestion (cellulase, hemicellulase, protease, etc.), separation, decolorization, sterilization, drying and other processes.

Soybean polysaccharide contains protein components, belonging to the amphoteric substances, concentrated lactic acid bacteria drink, the taste is acidic? Then the PH of the drink is lower than the isoelectric point of protein, soybean polysaccharide is positively charged, pectin belongs to the negatively charged colloid, the combination of the two will appear flocculation and precipitation.

(3) Consider the PH value of the sugar solution, the PH of the sugar solution before mixing should not be more than 5, otherwise the pectin is easy to degrade.