Method for chemically degrading high polymerization proanthocyanidins by means of sulfurous acid

Abstract

The invention discloses a method for chemical reduction and high polymerization of proanthocyanidins. The method utilizes the characteristic that sulfurous acid can degrade proanthocyanidins with a high degree of polymerization, and completes the conversion of proanthocyanidins from a high-polymerization state to an oligomerization state. The added sulfurous acid is precipitated by excessive calcium carbonate powder to generate another precipitated calcium sulfite. The precipitates are centrifuged or filtered to obtain oligomeric proanthocyanidins with a degree of polymerization of 2-3. The method simplifies the process steps, uses no organic solvent in the whole reaction, has extremely low requirements on equipment investment and workers' operation, is suitable for industrial production, and is a green chemical method that meets environmental requirements. The proanthocyanidin high polymer can be degraded into the proanthocyanidin oligomer, which increases the content of the oligomer in the raw material, and can ensure that the original components in the raw material remain unchanged to the greatest extent.

Description

technical field

[0001] The invention relates to a production method for obtaining oligomeric proanthocyanidins by sulfurous acid treatment, and belongs to the technical field of bioengineering. Background technique

[0002] Proanthocyanidins, also known as condensed tannins, are polymers formed by the condensation of flavans. It is formed by condensation of different amounts of catechin or epicatechin, forming dimers to dozens of polymer compounds, according to the degree of polymerization. Size, 2-4 polymers are usually referred to as oligomeric proanthocyanidins, and those with 5 polymers or more are called high polymer proanthocyanidins.

[0003] The biological activity of proanthocyanidins is related to the degree of polymerization of tannins. Previous studies on the biological activities of proanthocyanidins from other sources have shown that when the degree of polymerization is greater than 3, the solubility and antioxidant capacity of proanthocyanidins decrease with t...