Antioxidative enzymes, phytochemicals and proximate components in jujube fruit ( Ziziphus mauritiana L.) with respect to genotypes and harvest maturity

Abstract

Jujube is an underutilized fruit having high maturity variation at harvest. Investigations were made on eight different cultivars of jujube (Umran, Karela, Gurrh, Amrodia, Mehmood Wali, Aakash, Foladi and Khubani) for changes in antioxidative enzymatic activities, phytochemical functions and proximate composition with respect to different harvest maturity stages (M 1 : mature green, M 2 : yellow and M 3 : crispy brown) under postharvest ambient conditions (25 +/- 2 degrees C; 60 % -65 % RH) at three shelf intervals (1, 3 and 5 d). Significant genotypic and maturity related variation was recorded regarding studied attributes. The fruit of cv. 'Khubani ' had better attributes among the cultivars evaluated. The crispy brown jujube fruit had higher peroxidase (POD) and catalase (CAT) activity and more protein, total soluble solids (TSS), ash, crude fat and fiber than early mature stages. Over time, the ascorbic acid (vitamin C), titratable acidity (TA), total phenolic (TPC), total antioxidant capacity (TAC), crude protein, crude fiber, moisture, crude fat and activity of antioxidative enzymes [CAT and superoxide dismutase (SOD)] exhibited a significant decline; while increase was recorded in TSS, pH and POD activity. Overall, this work identified that jujube 's antioxidative, biochemical and proximate properties are significantly influenced by cultivar, fruit harvest maturity and duration of postharvest handling under ambient shelf.