Binding of Chinese quince oligomeric proanthocyanidins with different structures to sarcoplasmic and myofibrillar protein in chicken: Role of conformational changes and heterocyclic amine inhibition.

Proanthocyanidins (PAs) bound to proteins affected the inhibitory effect of heterocyclic amines (HCAs). This study evaluated how different structural PAs (catechin, CAT, and epicatechin gallate, ECG) interacted with sarcoplasmic (SP) and myofibrillar protein (MP), and how PA-protein complexes inhibited HCAs. The binding rate of ECG-protein complexes was higher than CAT-protein complexes. When combined with CAT or ECG, the α-helical structure of SP decreased from 12.8 % to 6.1 % or 6.6 %, respectively, while MP increased from 6.3 % to 7.7 % or 7.2 %, respectively. The thermal stability of ECG-protein complexes was stronger than ECG, while CAT-protein complexes were lower than CAT. SP-ECG and MP-ECG showed the strongest inhibitory effect on Norharman, which reached 62.21 % and 66.74 %, respectively. They better inhibited β-carbolines and intermediates than SP-CAT and MP-CAT, respectively. PAs bound to SP showed a stronger inhibitory effect of PhIP. The study provided a basis for HCAs inhibition by PA-protein complexes in fried foods.