Characterisation of odorant compounds and their biochemical formation in green tea with a low temperature storage process.
We produced low temperature (15°C) processed green tea (LTPGT) with higher aroma contents than normal green tea (Sencha). Normal temperature processed green tea (NTPGT), involved storing at 25°C, and Sencha had no storing process. Sensory evaluation showed LTPGT had higher levels of floral and sweet odorants than NTPGT and Sencha. Aroma extract dilution analysis and gas chromatography-mass spectrometry-olfactometry indicated LTPGT had 12 aroma compounds with high factor dilution values (FD). Among LTPGT’s 12 compounds, indole, jasmine lactone, cis-jasmone, coumarin, and methyl epijasmonatecontributed to floral, fruity and sweet characters. In particular, indole increased initially, peaking at 16 h, then gradually decreased. Feeding experiments suggested [15N]indole and [15N]oxygenated indoles(OX-indoles)were produced from [15N]anthranilic acid. We proposed the increase in indole was due to transformation of anthranilic acid during the 16 h storage and the subsequent decline in indole level was due to its conversion to OX-indoles.
Katsuno, T.; Kasuga, H.; Kusano, Y.; Yaguchi, Y.; Tomomura, M.; Cui, J.; Yang, Z.; Baldermann, S.; Nakamura, Y.; Ohnishi, T.; Mase, N.; Watanabe, N. 2014. Characterisation of odorant compounds and their biochemical formation in green tea with a low temperature storage process. Food Chemistry 148, 388–395.