Spatial distribution and time-course of polyphenol accumulation in grape berry (Vitis labruscana cv. ‘Kyoho’)

•The higher polyphenol concentration was accumulated in seeds than other tissues.•Significant polyphenol accumulation was detected during berry ripeness.•Polyphenols were most accumulated and biosynthesized in bottom grape berries.•Light had a negative effect on polyphenols accumulation at 25 ℃.•4 ℃ storage temperature caused increases in polyphenol levels during berry storage.