Changes in phenolic compounds in Litchi (Litchi chinensis Sonn.) fruit during postharvest storage

Litchi (Litchi chinensis Sonn. cv. Huaizhi) fruit were stored at ambient temperature (20-25°C) for up to 7 days and at 4°C for up to 35 days for separation, purification and identification of individual phenolic compounds and investigation of their changes during postharvest storage. Results indicate that flavan-3-ol monomers and dimers were major phenolic compounds representing about 87.0% of the phenolic compounds that declined with storage or browning. Cyanidin-3-glucoside was a major anthocyanin and represented 91.9% of anthocyanins. It also declined with storage or browning. Small amounts of malvidin-3-glucoside were also found. Therefore, the major substrates for enzymatic oxidation were apparently flavan-3-ol monomers and dimers and cyanidin-3-glucoside.