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Application of Microwave Energy in the Manufacture of Enhanced-Quality Green Tea

Author:
Gulati, Ashu, Rawat, Renu, Singh, Brajinder, Ravindranath, S.D.
Source:
Journal of agricultural and food chemistry 2003 v.51 no.16 pp. 4764-4768
ISSN:
0021-8561
Subject:
catechin, catechol oxidase, color, drying quality, energy, green tea, microwave treatment, odors, phenol, rolling, shoots, steaming, taste
Abstract:
Green tea manufacture was standardized with respect to the inactivation of polyphenol oxidase (PPO), rolling, and drying for quality manufacture. Inactivation of PPO by parching, steaming, microwave heating, and oven heating was monitored in tea shoots. The inactivated shoots were rolled under regimens of high and low pressures and dried by microwave heating, oven heating, or sun-drying; total phenols and catechins were estimated. Parched and sun-dried teas contained the lowest levels of total phenols and catechins, and their infusions were dull in color with a slightly burnt odor. Microwave-inactivated and-dried teas showed the highest levels of total phenols and catechins, and their infusions were bright in color and sweet in taste with a subtle pleasant odor. In steam-inactivated and oven/microwave-dried teas, total phenol and catechin contents were intermediate between parched and sun-dried teas and microwave-inactivated and microwave-dried teas, and their infusions were bright with a umami taste.
Agid:
322335