Active Packaging Systems to Extend the Shelf Life of 'Italia' Table Grapes

Sulfur dioxide (SO2)-generating pads associated with perforated plastic liners are often used to control gray mold in table grapes during cold storage; however, SO2 may cause bleaching, shattered berries, and an unwanted taste. To overcome this difficulty, a field ultrafast SO2-generating pad was designed to be used for a few hours before packaging grape bunches as an alternative for eradicating spores of fungi from berry skin. This study aimed to assess the postharvest conservation and shelf life of 'Italia' table grapes packaged in plastic clamshells and perforated plastic liners using the field ultra-fast SO2-generating pads before packaging, associated with or without slow- or dual-phase SO2-generating pads during cold storage. The packaged grapes were cold stored (1.0 +/- 1.0 degrees C; 95% relative humidity), and after 45 d, grapes were placed at room temperature (22.0 +/- 1.0 degrees C) without plastic liners and SO2-generating pads for 3 d. Before and after the grapes had been subjected to the field ultra-fast SO2-generating pads, the quantification of filamentous fungi on the surface of the berries was assessed. The use of field ultra-fast SO2-generating pads before packaging, associated with slow- or dual-phase SO2-generating pads during cold storage, resulted in a lower incidence of gray mold after 45 d of storage, with low weight loss and shattered berries, good preservation of stem freshness, and no impairment in the color and firmness of the berries. Additionally, a significant decrease in disease incidence was observed when using only the dual-phase SO2-generating pads in cold storage, with good maintenance of bunch quality.