Some physicochemical characteristics and degradation kinetic of anthocyanin of reconstituted pomegranate juice during storage

摘要

To investigate color quality in a systematic way, it is necessary to objectively measure color, as well as pigment concentration. The variation of anthocyanins content, chromatic parameters [L*, a*, b*, hue angle, chroma, and ΔE), pH, titratable acidity, and soluble solid content of reconstituted pomegranate juices were investigated at one month intervals during storage period at 4,20, and 37 ℃ for 210 days. The main anthocyanins quantified by HPLC-UV were cyanidin, delphinidin, and pelargonidin, 3-giucoside, and their 3,5-diglucoside. Juice color was investigated using Hunterlab colorimeter. The anthocyanin content and chromatic parameters of pomegranate juice changed significantly with increasing storage temperature and time (p < 0.05), and the degradation of pigments followed first-order reaction kinetics. The total anthocyanin content significantly correlated with the some chromatic parameters of the pomegranate juice. The soluble solid content and pH increased significantly during storage at all temperatures.