UPLC-Q-TOF-MS and NMR identification of structurally different A-type procyanidins from peanut skin and their inhibitory effect on acrylamide.

Abstract

Flavan-3-ol polyphenols have been shown to have great advantages in inhibiting acrylamide formation. However, flavan-3-ol polyphenols have structures that vary significantly, and existing research has been focused mainly on the effects of B-type procyanidins and structural units of procyanidins. This study aims to separate structurally different A-type procyanidins from peanut skin and compare their inhibitory effects on acrylamide in an asparagine-glucose simulation system. Five compounds were separated and identified from peanut skin, including epicatechin-(2β→ O→ 7, 4β→ 8)-ent-epicatechin, epicatechin-(2β→ O→ 7, 4β→ 8)-epicatechin, epicatechin-(2β→ O→ 7, 4β→ 8)-epicatechin-(4β→ 6)-catechin, epicatechin-(2β→ O→ 7, 4β→ 8)-epicatechin-(4β→ 8)-catechin, and epicatechin-(4β→ 6)-epicatechin-(4β→ 8, 2β→ O→ 7)-catechin. All the procyanidins could reduce the acrylamide content within a certain range of concentrations. The highest inhibition rates followed the order of compound 5 (A-type trimer) > compound 1 (A-type dimer) > compound 2 (A-type dimer) > compound 3 (A-type trimer) > compound 4 (A-type trimer). Comparison analysis showed that structurally different A-type procyanidins have various inhibitory effects on acrylamide production, which may be related to their spatial configuration and bond connection mode. Overall, our findings help us to gain a better understanding of the relationship between the structure of procyanidins and their inhibitory effects on acrylamide, particularly the inhibitory effect of A-type. There are potential practical implications if people use A-type procyanidins as acrylamide inhibitors in hot processed foods in the future. © 2022 Society of Chemical Industry.