Effect of Cold Storage of Various Pomegranate Cultivars Fruit Juices on Health Promoting Compounds and Their Activities

Abstract

In this study, the total anthocyanins, ascorbic acid and phenolic content in sixteen different pomegranate cultivars are reported as 2.6-11.6, 3.2-13.6 and 956.5-2450.3 mg/100 g, respectively. Total soluble solid content varied between 12.10-18.10Brix, whereas pH and % titratable acidity values were within the range of 2.87-4.65, and 0.27-3.39, respectively. Total sugar values were ranged 9.6-22.1 g/100g. The total antioxidant capacity of pomegranate cultivars were found to be 2.54-12.4 (ABTS), 5.5-36.2 (DPPH) and 3.9-26.7 (FRAP) µmol TE/g fw. A high correlation between total antioxidant capacity and total anthocyanins (r2= 0.94), ascorbic acid (r2=0.75) and phenolic content (r2=0.94) was observed. Moreover, total anthocyanin, ascorbic acid, total phenolic contents and the antioxidant capacity of four pomegranate cultivars were monitored at the refrigeration temperature for two months. It was shown that ascorbic acid concentrations of the samples significantly decreased during storage, while there was no degradation could be observed in total phenolic concentrations. The degradation of total anthocyanins of Mersin 23 and Mugla 1267 cultivars during storage resulted in a dramatic decrease in the total antioxidant capacity of these samples from 12.36 to 5.6 (µmol TE/g fw) and 9.9 to 5.3 (µmol TE/g fw), respectively. These results demonstrated that ascorbic acid, total anthocyanins and total phenolic compounds are the main contributors for initial total antioxidant capacity and the difference between the cultivars are significant. However, degradation of ascorbic acid was shown to have no significant effect on the total antioxidant capacity unlike the total anthocyanins and phenolic compounds.