Screening of epigallocatechin-3-gallate (EGCG) content in camellia sinensis products

Abstract

Epidemiological studies have proven the influences of tea consumption in prevention of chronic diseases. Tea (Camellia sinensis) is a major source of epigallocatechin-3-gallate (EGCG) compound with pharmacological properties such as anti-obesity, anti-diabetes, anti-inflammation. The aims of this study is to analyze and compare the EGCG content in commercialized tea-based products, infusion tea and ready-to-drink tea beverages available in the local market. This study is divided into two phases. The first phase involved the extraction of EGCG compound from four types of tea namely as white tea (WT), green tea (GT), oolong tea (OT) and black tea (BT) using aqueous and methanol extraction techniques. The amount of EGCG is determined using HPLC. The second phase involved the characterization of EGCG compound in infusion tea bags (ITB) and ready-to-drink tea beverages (RTD) using HPLC. Our findings recorded that GT contain the highest EGCG concentration in comparison to other tea types using both methanol and aqueous extraction methods. Temperature and extraction time have influence on the extraction yield. This study also revealed that ready-to-drink tea beverages contains significantly lower level of EGCG compared to the infusion tea hence makes ready-to-drink beverages less healthy for consumption especially for obese and diabetics individuals.