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

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.