Changes in the concentrations of acrylamide, selected odorants, and catechins caused by roasting of green tea.
This research aims to optimize roasted green tea (Houjicha) processing by using roasting treatments to achieve acrylamide mitigation without compromising the quality. 2-Ethyl-3,5-dimethylpyrazine and 2-ethyl-3,6-dimethylpyrazine were identified as potent odorants by aroma extract dilution analysis. In preliminary sensory experiments, the desirable Houjicha flavor was produced in products roasted at 160 degrees C for 30 min and at 180 degrees C for 15 min. Under these conditions, potent odorants were formed at levels adequate for contributing to the Houjicha flavor. Acrylamide amounts in tea infusions were 2.0 and 4.0 microg/L by roasting at 160 degrees C for 30 min and at 180 degrees C for 15 min, respectively. Compared to roasting at 180 degrees C, the degradation of tea catechins was suppressed by roasting at 160 degrees C. Hence, roasting at 160 degrees C for is recommended for Houjicha processing for acrylamide mitigation, formation of potent odorants, and suppression of degradation of tea catechins.
Mizukami
Yuzo
Y
National Institute of Vegetable and Tea Science, 2769 Kanaya, Shimada, Shizuoka 428-8501, Japan. myuzo@affrc.go.jp
Sawai
Yusuke
Y
Yamaguchi
Yuichi
Y
D020106:Acrylamide / Q000032:analysis*; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000032:analysis*; D006358:Hot Temperature; D006801:Humans; D009812:Odorants / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry*; D013649:Taste; D013662:Tea / Q000737:chemistry
D013662:Tea; D020106:Acrylamide; D002392:Catechin