Effects of ultrasound-assisted extraction procedure on  total phenolics, catechin and caffeine content of green  tea extracts

Emine Ateş; Cemal Kaya; Esra Esin Yücel; Mustafa Bayra

doi:10.9755/ejfa.2022.v34.i8.2911

Authors

Emine Ateş Department of Food Engineering, Institute of Science, Tokat Gaziosmanpaşa University, 60250 Tokat, TURKEY
Cemal Kaya 2 Department of Food Engineering, Tokat Gaziosmanpasa University, 60250 Tokat, TURKEY
Esra Esin Yücel Department of Food Engineering, Tokat Gaziosmanpasa University, 60250 Tokat, TURKEY
Mustafa Bayra Department of Food Engineering, Tokat Gaziosmanpasa University, 60250 Tokat, TURKEY

DOI:

https://doi.org/10.9755/ejfa.2022.v34.i8.2911

Abstract

This study was conducted to investigate the changes encountered in water soluble dry matter (ºBrix), total phenolics, caffeine and some important catechins of green tea extracts extracted through ultrasound-assisted extraction procedures. Extractions were conducted at
70°C temperature, different tea: water ratios (5:100; 10:100) and brewing times (5, 10 and 20 min) and resultant extracts were also supplemented with tannase enzyme. Total phenolics of green tea extracts varied between 2.68 - 3.87 g GAE/100 g dry green tea. The greatest total phenolics (3.87 g GAE/100 g dry green tea) was obtained from 20 min brewing at 70°C and 10:100 tea: water ratio of tannase enzyme-supplemented extract. As compared to the control samples, decreasing EGCG and ECG contents and increasing EGC and EC contents were observed with tannase enzyme supplementations.