Effects of Clarification and Storage on Anthocyanins and Color of Pomegranate Juice Concentrates

Whole pomegranates with rinds were processed into juice and then concentrate. Effects of cold clarification and storage temperatures (-23C, 5C, 12C and 20C) on anthocyanins (ACNs), ACN composition and color were determined. Major ACNs in pomegranate juice concentrate (PJC) were identified as cyanidin-3,5-diglucoside (47.9%), delphinidin-3,5-diglucoside (23.2%) and cyanidin-3-glucoside (18.5%). Diglucosides were more stable than monoglucosides during storage. ACN degradation and polymeric color formation were fitted to first-order reaction models. Higher storage temperatures increased the rate of ACN degradation and polymeric color formation in PJCs. Good correlation (r=-0.988) was found between ACN degradation and polymeric color formation during storage. Rate of ACN degradation and polymeric color formation were slower in the PJC obtained from unclarified juice than PJC obtained from clarified juice during storage. © 2012 Wiley Periodicals, Inc