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Study on the quality characteristics of processed green tea extract during storage period

Corresponding Author : Wahidu Zzaman (wahid-ttc@sust.edu)

Authors : M.M. Haq (muhiminulhaq@yahoo.com)

Keywords : Green tea, Antioxidant activity, Sensory quality, Storage quality

Abstract :

Green tea is made from Camellia sinensis leaves that have undergone minimal oxidation during processing and helps to reduce the risk of cardiovascular disease and some forms of cancer. A study was conducted to evaluate the changes in quality characteristics of processed green tea extract for 21 days. Green tea extract was prepared in the laboratory scale with the addition of two different green tea from Kazi & Kazi (K-1) and Finlay (F-1), honey and ginger juice. The changes in total phenol content, DPPH scavenging effect, caffeine content, and sensory quality were analyzed during the storage period. The DPPH scavenging effect decreased slightly 97.17% to 84.51 % for F-1 and 97.84 % to 85.50 % for K-1 in the storage period of 7 to 21 days respectively for 50000 µg/ml concentration. For other concentration DPPH activity also decreased gradually during the storage period. Similarly the total phenol content decreased slightly from 4.13 (GAE mg/100gm) to 2.99 (GAE mg/100gm) for K-1 and 3.59 (GAE mg/100gm) to 3.0 (GAE mg/100gm) for F-1 in storage period whereas level of caffeine increased from 42.17 to 64.09 (ppm for K-1 and from 41.82 to 60.26 (ppm) for F-1 in during storage period. The sensory quality of K-1 was better than the F-1 with the score of overall acceptability 6.2 and 5.9 respectively. The study results might help to consider the quality changes of green tea extract during the storage period to introduce a green tea-based beverage.

Published on August 4th, 2019 in Volume 1 Issue 1, Chemical, Food processing, Petroleum and mining