Antimicrobial and antioxidant activity of muscadine ( Vitis rotundifolia Michx) extracts as influenced by solvent extraction methods and cultivars

Muscadine seeds from three cultivars (`Carlos', `Noble' and `Ison') were processed by 100% v/v methanol, 95% v/v ethanol and 70% v/v acetone. The acetone seed extracts exhibited the highest (p<0.05) total phenolics (21.62∼24.84mg/g of dw) and antioxidant activity. A strong correlation (R2=0.891/p<0.01) was found between total phenolics and antioxidant activity. Methanol and `Carlos' seed extracts generally showed the highest antimicrobial capacity against pathogen strains tested, which correlated well with tannic acid, catechin, epicatechin and tartaric acid content. Hot water-soluble muscadine skin extracts from 17 muscadine cultivars (6 bronze and 11 dark) showed effective antioxidant properties. Significant variations (p<0.05) were observed among the 17 cultivars in total phenolics, organic acids and antioxidant activity. `Alachua', `Albermarle', `Southland', `Janebell' and `CA9-37' were the cultivars found to have the highest antioxidant capacity. Skin extracts of dark-skin cultivars showed higher (p<0.05) content than bronze-skin cultivars in phenolics, tartaric acid, tannic acid and ellagic acids.