Analysis of the aroma change of instant green tea induced by the treatment with enzymes from Aspergillus niger prepared by using tea stalk and potato dextrose medium. (12th July 2017) - Zhu, Yan Bing
Abstract: The effects of two crude enzymes from Aspergillus niger on the aromas of instant green tea have been investigated. The crude enzymes from tea stalk (ETS) and potato dextrose (EPD) were respectively prepared by fermentation. Both enzyme extracts significantly changed the volatile composition and aroma profile. ETS treatment increased the content of 2‐ethylfuran, ethyl 2‐methylbutyrate and decanal and decreased the content of trans ‐limonene oxide and 2‐heptanone; EPD treatment increased the concentrations of 2‐ethylfuran and ethyl 2‐methylbutyrate and decreased the concentrations of octanal, methyl salicylate and trans ‐limonene oxide. After ETS treatment, the floral and fermented notes increased, while green, woody and sweet notes decreased. EPD treatment decreased green and floral notes. These results indicate that both ETS and EPD contain some novel enzymes, which could modulate the aroma of instant green tea, and thus provide potential enzyme resources for modulating the aroma of tea products. Abstract : Both ETS and EPD treatments could significantly improve the aroma of instant green tea due the changes of volatile constituent. I.e., the treatment of ETS increased the content of 2‐ethylfuran, ethyl 2‐methylbutyrate and decanal and decreased the content of trans‐limonene oxide and 2‐heptanone; the treatment of EPD increased the concentrations of 2‐ethylfuran and ethyl 2‐methylbutyrate and decreased the concentrations of octanal, methyl salicylate and trans‐limonene oxide.