Aroma profiles of green tea made with fresh tea leaves plucked in summer.

There is a claim that fresh tea leaves plucked in summer (FTL-S) are not suitable for green tea processing, but there is no scientific evidence to support this claim. The aroma properties of green tea (GT-S) made with FTL-S were studied by the analysis of volatiles during process, coupled with odor activity value (OAV) determination. The odor profiles of dry tea and tea infusion were investigated by sensory evaluation. The GT-S contained higher proportions of alcohols, alkenes and heterocyclic compounds with strong fragrance and nutty odors as well as moderate floral odor in comparison with FTL-S. β-Damascenone and 2-ethyl-3,5-dimethylpyrazine with the OAV of 54,290 and 1.15, respectively, were the aroma-active compounds imparting woody and nutty odors in GT-S, respectively. Current study provides an alternative way to use FTL-S for green tea production, and we also found that L-theanine is an important aroma precursor for the formation of green tea aroma.