STORAGE RETENTION OF STILBENE, ELLAGIC ACID, FLAVONOL, AND PHENOLIC CONTENT OF MUSCADINE GRAPE (VITIS ROTUNDIFOLIA MICHX.) CULTIVARS

The presence of ellagic acid and other nutraceutical compounds in muscadine grapes add value and enhance the marketability of this southern U.S. specialty crop.? Due to its nutraceutical profile, muscadines may potentially become the next “super fruit”.? The objective of this study was to determine the retention of important phytochemical compounds including anthocyanins, phenolics, flavonols, stilbenes and organic acids from whole muscadine grape berries and individual fruit parts following cold storage. ?Stilbene, ellagic acid, flavonol, and phenolic compounds were analyzed in berries of 11 muscadine grape cultivars following 14 days of cold storage at 4°C.? The major phenolic compounds were identified by their retention times and characteristic spectra. ?Quantification was made by utilizing calibration curves of external standards for each of the analyzed compounds including trans- and cis-resveratrol, trans- and cis-piceid, ellagic acid, myricetin, quercetin and kaempferol.? Total phenolics decreased in 6 cultivars but increased in 5 cultivars, suggesting differences in decay development and fruit deterioration. Anthocyanin content showed an overall decrease in all cultivars except ‘Eudora’.? Stilbenes showed an overall decrease across cultivars, but flavonol content was cultivar and compound specific.? Free ellagic acid increased in all cultivars, except ‘Pollyanna’, and total ellagic acid increased or remained constant in all cultivars.?