Effects of different spreading treatments on the formation of aroma quality in green tea

Abstract

This experiment was aimed to verify if low-temperature spreading treatments (CK, natural spreading; LTD, low temperature + dark; LTY, low temperature + yellow light; LTCD, low temperature + CO₂) had a positive effect on the aroma quality of green tea products under the premise of prolonging the spreading period of picked tea leaves. Compared to CK, LTY significantly improved the aroma quality in green tea products. The spreading leaves with LTY treatment showed the highest relative content of terpene volatiles and amino acid-derived volatiles. Furthermore, terpene precursor synthesis genes, such as linalool synthase genes (<i>CsLIS2, CsLIS3, CsLIS4</i>) and farnesene synthase genes (<i>CsFS5, CsFS10</i>) were significantly up-regulated in spreading leaves after LTY treatment. This research enriches our understanding of volatile metabolism in postharvest tea leaves and provides a genetic metabolic basis for the application of low-temperature spreading in green tea processing.