Tea polyphenols are a general term for polyphenolic substances in tea, including flavanols, anthocyanins, flavonoids, and phenolic acids, accounting for approximately 15%–25% of dry tea, and are easily soluble in water. These substances, also known as tea tannins, are the main cause of astringency in green tea. In the production and processing of tea beverages, the presence of tea tannins affects the taste and quality of the product.
Tanninase is an extracellular enzyme produced by Aspergillus niger. It can hydrolyze the ester bonds and phenolic carboxyl bonds in gallic acid tannins to produce gallic acid and glucose. It can be used in tea beverage processing to reduce the astringency caused by tea tannins, improving the taste and quality of tea beverages.
