Physicochemical and Antioxidant Changes in Six Alabama-grown Blackberry Cultivars

Abstract

Blackberries are an excellent source of natural antioxidants. Fully ripened fruit of `Apache', `Arapaho', `Chester', `Loch Ness', `Navaho', and `Triple Crown' thornless blackberries were evaluated for their physicochemical and antioxidative activity. Differences in initial pH, titratable acidity (TA), total soluble solids (TSS), TSS/TA ratio and soluble sugars (reducing sugar, sucrose, and total sugars) differed among cultivars. Differences among cultivars with respect to reduced ascorbic acid (AA) were established, but there were no differences in either oxidized ascorbic acid (DHA) or total ascorbic acid (TAA) content. Antioxidant activity was determined by ABTS radical cation procedure for fractionated crude fruit extracts and the cultivars varied in the parameters evaluated. Hydrophilic antioxidant activity (HAA) was not different among cultivars evaluated. In contrast, lipophilic antioxidant activity (LAA) and total antioxidant activity (TAA) differed. The results obtained in this study indicate that Alabama-grown blackberries vary in their quality indices and are an excellent source of natural antioxidants. Information compiled will assist in marketing, handling, postharvest storage of these fruit and serve as a guide to partial fulfillment of recommended daily dietary requirements.