Jeffrey K. Brecht

Muscadine grapes ( Vitis rotundifolia Michx.) are delicate in nature with short shelf life. Postharvest technologies like modified atmosphere packaging (MAP) with reduced oxygen (O 2 ) and elevated carbon dioxide (CO 2 ) could increase the postharvest storage life with better quality. In the current experiment, physical and biochemical quality attributes of black and bronze cultivars of muscadine grapes ('Supreme' and 'Granny Val', respectively) were evaluated in active MAP. Fruit were packed in plastic trays, sealed with impermeable film, and CO 2 was introduced into the package. The MAP was created by a rigid microperforated plastic patch coated with a proprietary semipermeable resin, which was applied over a hole in the tray; packages with the same size hole without a patch were the control. Fruit were stored at 4°C for 42 days (6 weeks). MAP resulted in significantly lower decay incidence and better retention of fruit firmness for up to 28 days of storage in both cultivars as well as reducing color changes in 'Supreme' fruit. Although MAP did not affect the biochemical quality of muscadine grapes, total antioxidants increased initially and then decreased during storage, irrespective of packaging treatments. A significant linear increase in total phenolic content was also found during storage, regardless of treatments applied. Overall, the results of the current study demonstrate that MAP can be an affective technology to increase storage duration of muscadines with better retention of physical quality, without affecting the biochemical attributes.