Effect of ultrasonic modification on the binding ability of pectin to anthocyanin

Abstract

BackgroundPectin was considered as a potential candidate to improve the thermal stability of anthocyanins, and the binding ability of pectin to anthocyanins was influenced by its structure. In this study, sunflower pectins, modified by ultrasound (40 kHz) with different time, were prepared and used to bind with anthocyanins, extracted from purple sweet potato.ResultsCharacterization and thermal stability of pectin‐anthocyanin complexes were then investigated. The ultrasonic modification of pectin resulted in many changes in pectin chemical structure, including the degradation of neutral sugar side chains, the breakage of methoxyl groups, and the increase of molecular flexibility. And the extension of ultrasonic modification time led to the larger changes of pectin chemical structure. The analysis of the binding ability, as determined by Fourier transform infrared spectroscopy (FTIR) and molecular dynamics (MD) simulations, revealed that the interaction between pectin and anthocyanins was driven by hydrogen bonding, electrostatic interaction, and hydrophobic interaction. The pectins with different ultrasonic modification time bound with anthocyanins to different amounts, mainly resulted from an increase in the number of hydrogen bonds. According to the HPLC analysis, during the heating at 90 °C, The stronger the binding ability of pectin and anthocyanin complex, the better its thermal stability.ConclusionThus, ultrasonic modification of pectin could effectively enhance its binding ability of anthocyanin.This article is protected by copyright. All rights reserved.