Enzyme-assisted dynamic extraction as a promising method to produce high-quality fresh tea juice from summer tea leaves

Abstract

To improve the flavor of green tea juice processed from summer tea leaves, the enzyme-assisted dynamic extraction method was applied. The chemical components and taste of fresh green tea juice prepared under different extraction conditions with enzyme treatment (EM: tannase or its combination with protease/cellulase/pectinase) were investigated. The results showed that EM could reduce the bitterness and astringency of the tea juice by up to 40 % and 39 %, and enhance the sweet aftertaste to 132 %. These improvements resulted from a significant decrease in ester catechins and an increase in non-ester catechins and gallic acid. In addition, it was also found that the tea juice extracted with EM had less sediment (73 %) and better stability. Therefore, combined dynamic extraction with EM for the extraction of green tea leaves could effectively improve the taste, and increase the extraction rate of tea juice, promoting the utilization rate of abandon-plucked tea leaves in summer.