Akademik Veri Yönetim Sistemi
Bulgarian Chemical Communications, cilt.53, sa.4, ss.405-411, 2021 (Scopus)
Green tea is one of the extensively used drinks in the world. Green tea extract contains several polyphenolic compounds and catechins. Epigallocatechin-3-gallate (EGCG) and epicatechin 3-gallate (ECG) are the most effective antioxidants. In this study, the relation between EGCG content and the antioxidant effect of samples purchased from four different manufacturers was investigated. The antioxidant effects of blended tea samples which contain additives (such as ginger, lemon) and pure green tea samples were compared via DPHH• and ABTS+• radical scavenging tests and β-carotene linoleic acid inhibition methods. The total ash content of green tea samples was determined according to the ISO 1575 test method. All samples were analyzed for trace elements by flame atomic absorption spectrometry (FAAS) after wet digestion. Some tea samples showed a higher (-)-EGCG content (e.g. 164.27 μg in 1 mL infusion for GT-A7), nevertheless, all samples possessed good antioxidant activity. GT-A6 showed the highest level of DPPH• scavenging activity with 86.0 ± 0.1% inhibition. The TEAC value of GT-A5 and GT-A7 was determined to be 2.58 mmol/L/Trolox. The results of the total ash content (in the range of 5% to 7%) and of the trace elements contents suggest that all tea samples are of high quality.