The color expression of copigmentation between malvidin-3-O-glucoside and three phenolic aldehydes in model solutions: The effects of pH and molar ratio

卷:199

Zhang, Bo ; He, Fei ; Zhou, Pan-Pan ; Liu, Yue ; Duan, Chang-Qing

China Agr Univ

关键词: Copigmentation;    Phenolic aldehyde;    pH and molar ratio effects;    Chromatic characteristics;    Experimental and theoretical investigations;   

DOI  :  10.1016/j.foodchem.2015.12.008

学科分类：食品科学和技术

【 摘 要 】

Copigmentation was investigated in model solutions between the anthocyanin malvidin-3-O-glucoside and three phenolic aldehydes (vanillic, syringic and coniferyl aldehydes) as a function of the pH and the pigment/copigment molar ratio. Tristimulus colorimetry was applied to evaluate the chromatic variations induced by copigmentation process. The results indicated that the greatest magnitude of copigmentation was obtained at pH 3.0 and molar ratio of 1: 100, being significantly higher with coniferyl aldehyde, followed by syringic and vanillic aldehydes. The equilibrium constant (K) and Gibbs free energies (Delta G degrees) determined here show a spontaneous exothermic reaction. Theoretical calculations (Delta G(binding), Delta E) specified the relative arrangement of the pigment and copigment molecules within the complexes. In addition, an atoms in molecules (AIM) analysis was used to explore the main driving forces contributing to the formation of copigmentation complexes. (c) 2015 Elsevier Ltd. All rights reserved.