Brief gaseous shocks to inhibit postharvest gray mold on 'Mollar de Elche' pomegranates

Abstract

Spain is the first European Union producer and exporter of pomegranates (Punica granatum L.) and ‘Mollar de Elche’ is the most important cultivar. Studies show remarkable benefits from pomegranate consumption on human health mainly due to the high antioxidant activity of this fruit. As new markets based on the manufacture of derived functional food products are arising, longer storage life of fresh pomegranates is demanded. Decay due to gray mold, caused by Botrytis cinerea, is one of the most important factors limiting storability of pomegranates. In Spain, no postharvest chemical treatments are permitted and alternative antifungal methods are required. In this work, pomegranates cv. ‘Mollar de Elche’ were artificially inoculated with B. cinerea and exposed 24 h later to air (control), 95 kPa CO2, or 30 kPa O2 + 70 kPa CO2 at 20°C and 90% RH for 48 h, and subsequently stored at either 20°C for 12 days or 5°C and 90% RH for 2.5 months. On pomegranates incubated at 20°C, exposure to 95 kPa CO2 reduced gray mold incidence by 97 and 63% compared to control fruit after 2 and 5 days, respectively. However, this reduction gradually decreased along the incubation period. Decay incidence was not significantly reduced on pomegranates treated with the mixture 30 kPa CO2 + 70 kPa CO2. On pomegranates stored at 5°C, both gaseous shocks reduced gray mold incidence by 80 and 40% after 12 and 26 days of storage, respectively, but the treatments lacked persistence.