Method for determining methoxy content in hemp pectin

Abstract

The invention discloses a method for measuring methoxyl content in hemp pectin. The method uses hemp pectin esterase to hydrolyze the pectin ester bond, and obtains the methoxyl content through acid-base titration measurement, which specifically includes: S1, dissolving hemp pectin in deionized water, and adding the first alkaline solution to neutralize its free carboxyl groups to obtain a pectin solution; S2, adding hemp pectin esterase to the pectin solution obtained in step S1 , control the hydrolysis temperature to 35-45°C, and the hydrolysis time to 20-40min to obtain hemp pectin enzymatic hydrolyzate; S3, add the second alkaline solution to the hemp pectin enzymolyzate obtained in step S2, An acid-base neutralization reaction occurs, and the methoxyl content in hemp pectin is calculated by the consumption of the second alkaline solution. It has the advantages of strong consistency, high efficiency, mild action conditions, and less amount of sample to be tested.

Description

technical field [0001] The invention relates to the technical field of biochemistry, in particular to a method for determining the methoxyl content in hemp pectin. Background technique [0002] Pectin is a structurally complex polymer found in plant cell walls. At present, the raw materials of commercial pectin are mainly citrus peel, lemon peel and apple peel, while hemp pectin has high medicinal value and economic value due to its unique composition, and has potential development prospects in the future. [0003] The structure of pectin is mainly composed of α-D-1 and 4-GalA, and the carboxyl group of GalA has different degrees of methyl esterification (-COOCH 3 ). The degree of esterification (DE) is a routine index for the analysis of the physical and chemical properties of pectin. Different degrees of esterification affect the solubility, gelation, stability and emulsification of pectin products, and are one of the factors that determine the gel mechanism. major fact...

AI Technical Summary

Problems solved by technology

Among them, the most commonly used method is saponification titration, which has the advantages of easy operation, good repeatability, and strong stability; while the rest of the methods including spectrophotometry, gas chromatography, high performance liquid chromatography, etc. require a price Expensive instruments and equipment, high measurement cost, difficult to apply and popularize

However, it is worth noting that the saponification titration method also has some obvious shortcomings such as the large amount of test samples and the use of strong acids and strong bases involved in the operation process, which greatly restricts its application in the determination of methoxyl content.

Images