DEGRADATION KINETICS OF ANTHOCYANIN IN ETHANOLIC SOLUTIONS

Abstract

The objective of this study was to investigate the degradation kinetics of anthocyanin in ethanolic model solutions simulating wine and liqueur in aging or long-term storage. Malvidin-3-glucoside, as the predominant anthocyanin in many cultivars of grape, was chosen to represent anthocyanins. The results from high performance liquid chromatography analysis show that the disappearance of malvidin-3-glucoside follows apparent first-order kinetics, and accelerates with the increase in ethanol concentration. The Ea values were found to be 22.80, 24.45, 24.35 and 22.75 kcal/mole at 0, 10, 30 and 50% ethanol concentrations, respectively. We propose that the decreased stability of anthocyanin at an elevated ethanol concentration is a result of a decreased extent of self-association in the solution.