The comparison between total phenolic content and antioxidant activity of gyokuro, sencha and matcha from some tea store in Chiang Rai and Bangkok

Abstract

The objective of this study is to compare the total phenolic content and antioxidant activity between gyokuro, sencha and matcha from Chiang Rai and Bangkok. This research is very helpful for customers to choose the best green tea based on scientific studies. The result, sencha samples from Bangkok noted that sencha contains the most total phenolic content (179.07 ± 1.15 mgGAE/1gextract, gyokuro(91.64 ± 0.15 mgGAE/1gextract) and matcha (78.51 ± 0.45 mgGAE/1gextract), and sencha is shown to have the highest antioxidant activity (IC50equal to 0.0077 ± 0.0001 mg/ml), gyokuro(IC500.0140 ± 0.0006 mg/ml) and matcha (IC500.0191 ± 0.0005 mg/ml). Samples from Chiang Rai noted that sencha contains the most total phenolic content (105.56 ± 0.31mgGAE/1gextract), matcha(101.08± 0.12 mgGAE/1gextract) and gyokuro(72.91 ± 0.07 mgGAE/1gextract). Sencha has the highest antioxidant activity (50%inhibitoryconcentration (IC50) equal to 0.0084 ± 0.0001 mg/ml),matcha (IC50is equal to 0.00168 ± 0.0005 mg/ml) and gyokuro(IC50is equal to 0.0232 ± 0.0004 mg/ml. Based on the amount of total phenolic content and antioxidant activity, It can be concluded that sencha is the best type of green tea for consumption. Most green tea samples contain higher antioxidant activity than the BHT standard, especially the sencha sample from Bangkok has higher antioxidant activity than the BHT standard byaround2-folds. Many factors are involved in the amount of total phenolic content and antioxidant activity such as sunlight, storage duration, pH value, oxygen, temperature, ingredients in products etc.