Beneficial effects of high pressure processing on the interaction between RG-I pectin and cyanidin-3-glucoside

•HPP treatment promoted C3G and RG-I pectin binding capacities.•Microstructural changes in the C3G-RG-I pectin complex occurred after HPP treatment.•HPP maintained the antioxidant capacity of C3G and improved the stability of C3G.•C3G-RG-I pectin complex improved health functionalities of fruit and vegetable juice. In the present study, the effects of high-pressure processing (HPP) on the binding capacity, structural properties, antioxidant capacity and stability of rhamngalacturonan I (RG-I) pectin and cyanidin-3-glucoside (C3G) were investigated. HPP was found to have a positive effect on the binding between the two molecules, and the binding rate was increased by 32.8% after treatment (500 MPa/15 min). The increase in the binding rate is mainly due to the influence of high pressure on noncovalent effects such as hydrogen bonding and hydrophobicity. The results indicate that high pressure can be used to maintain the antioxidant capacity of C3G and improve the stability of C3G. The C3G retention rate is increased by 34.0% and 38.3% after heat treatment and simulated digestion, respectively. The results indicate that HPP improved stability of the C3G-RG-I pectin complex through interaction between C3G and RG-I pectin.