Effect of extraction methods on the chemical components and taste quality of green tea extract.

The physicochemical properties of tea extracts are significantly affected by the extraction method. The aim of this study was to compare the effects of static and dynamic extractions on the concentrations of chemical components and taste quality of green tea extracts. Our results show that extraction of chemical components using static extraction follows a pseudo-second-order reaction, while that of dynamic extraction follows a first-order reaction. The concentrations of the solids, polyphenols, and free amino acids in green tea extract prepared by dynamic extraction were much higher, although the overall yields were not significantly different between the two extraction methods. Green tea extracts obtained via dynamic extraction were of lower bitterness and astringency, as well and higher intensities of umami and overall acceptability. These results suggest that dynamic extraction is more suitable for the processing of green tea concentrate because of the higher concentration of green tea extract.