Impact of kernel development on phenolic profiles and antioxidant activity in Castanea henryi

Summary The changes in the phenolic profiles during the kernel development of two varieties of Castanea henryi (‘Jinzhui’ (YS) and ‘Baiyan No.1’ (WS)) were investigated based on content levels and gene expression levels. The results showed that the total phenolic content (TPC) increased during the Castanea henryi development and were mainly dependent on the content variation of gallic acid and (‐)‐epicatechin. Gene C4H positively affected the accumulation of p‐coumaric acid, while gene CHI and F3H positively affected the biosynthesis of (‐)‐epicatechin. Four assays including DPPH, FRAP, ABTS and ORAC were conducted to evaluate the antioxidant quality of Castanea henryi extracts. The results showed that the Castanea henryi developed at S4 (stage 4) possessed the better antioxidant quality. In addition, in both varieties, FRAP and ORAC value were more likely to be influenced by the variation of gallic acid and (‐)‐epicatechin concentrations, respectively. The DPPH value in YS was dependent on the syringic acid and the gallic acid content in WS.