The Effect of High-Pressure Processing on the Copigmentation and Storage Stability of Polyphenols with Anthocyanin Monomers

This study aims to determine the effect of different high-pressure processing (HPP) conditions (100 MPa/300 MPa/500 MPa; 2 min/4 min/6 min) on copigmentation, specifically between chlorogenic acid (CA), epicatechin (Epi), gallic acid (GA), malvidin-3-O-galactoside (Mv-3-O-gal), and malvidin-3-O-arabinoside (Mv-3-O-ara), as well as the storage stability of the copigmentation solutions. The results showed that the influence of different HPP treatment conditions on copigmentation was not significant. HPP treatment did not significantly affect the λ_max, peak absorption, color parameters, and Mv-3-O-gal anthocyanin content when applied alone or in combination with CA and Epi. However, the color intensity and <i>a</i>* value of Mv-3-O-gal with GA decreased by 3.2% (<i>p</i> < 0.05). The absorption peak, color, and content of Mv-3-O-ara were not affected by HPP alone or during copigmentation with CA, Epi, and GA. In addition, CA had the best effect on the co-coloring of Mv-3-O-gal, while GA was more successful in affecting Mv-3-O-ara during the storage period. Molecular dynamics simulations indicated that the aromatic ring of CA was closest to the A-C plane of Mv-3-O-gal (3.70 Å), resulting in a closer π-π stacking distance and higher bond energy. The favorable impact of GA on Mv-3-O-ara was because the A-C plane aromatic ring of Mv-3-O-ara and the aromatic D ring of GA formed "sandwich" stacking. The results indicated that combining HPP with polyphenols improved color and could be used to process raw materials containing malvidin, such as blueberries.