Effects of pasteurization and storage on turbidity and copigmentation in pomegranate juices clarified with various hydrocolloid combinations

Abstract

Success of clarification treatment in pomegranate juice is related to prevention of after-bottling haze formation and high anthocyanin content after pasteurization and during storage. Therefore, this study was conducted to achieve these targets with hydrocolloid [albumin (A), casein (C), chitosan (CH) and xanthan gum (XG)] combinations. While C, “A + XG” and “A + C” resulted in the greatest clarity after pasteurization, “A + C” and “A + C + CH” were associated with the greatest clarity during storage. In comparison with “A + C + CH” (k = 0.053 week−1), “A + C” (k = 0.065 week−1) was associated with more rapid improvement in clarity (23%). Greater clarity of “A + C” was associated with reductions in contents of punicalagins (r = −0.963), gallic (r = −0.936), chlorogenic (r = −0.995) and ellagic (r = −0.989) acids. However, “A + C + CH” clarity was associated with fewer proteins. Since copigmentation occurred between anthocyanins and phenolics, “A + C” enhanced colour density stability better (1.1 times) than “A + C + CH.” Therefore, “A + C” is recommended producing pomegranate juice with high clarity and colour density after pasteurization and during storage.