Fig 2.

General procedure of experimental design: (A). Tannins were extracted from grape seeds; (B). Technique of CPC fractionated tannins according to their DP size; (C). Purified compounds were identified by UHPLC-HRMS; (D). Salivary protein binding abilities of purified oligomers were assessed by measuring difference between tannins with and without saliva; (E). Astringency intensities of monomeric, dimeric, trimeric, tetrameric and pentameric tannins in model wine solution were estimated.