Influence of postharvest ozone treatment on decay of 'Red Globe' table grapes
Ozone (O3) is a strong antimicrobial agent, in the category of Generally Recognized As Safe (GRAS) and therefore lightly regulated. An investigation was conducted to assess the effect of O3 on postharvest decay of 'Red Globe' table grapes stored for 20 days at 1±1°C and then maintained for 4 days at 23±1°C to simulate the store/market environment. O3 was applied at 0.2 µL L-1. Grapes were un-packed or packed in plastic bags, and the packed grapes were tested with and without SO2 pads. Decay severity was expressed through the McKinney index, which expresses the weighted average of the disease severity as an actual percentage in terms of the maximum disease severity. The quantification of fungi and yeasts was done by counting the colony forming units (CFU). A significant reduction of table grape decay was observed in samples treated with O3 packed in plastic bags with SO2 pads and in un-packed samples. In particular, O3 at 0.2 µL L-1 inhibited the aerial growth of the mycelia and reduced the CFU of fungi and yeasts commonly present on grape berries such as Botrytis sp., Penicillium sp., or Mucor sp. Thus, O3 prevented rot spreading from decayed fruit to adjacent healthy ones. Therefore, O3 treatment could be an alternative to, or integrated with, the use of SO2.
Yaseen, T., Ricelli, A., Albanese, P., Essakhi, S., Carboni, C. and DOnghia, A.M. (2016). Influence of postharvest ozone treatment on decay of 'Red Globe' table grapes. Acta Hortic. 1144, 371-376
fungi, contamination, grey mould, McKinney index, alternative control means