Microbial populations of Botrytis cinerea-inoculated strawberry fruit exposed to four volatile compounds

Abstract

Aerobic, microaerophilic, coliform, and mold populations of Botrytis cinerea-inoculated strawberry fruit not exposed (control or exposed to low and high quantities of four volatile compounds during storage at 2°C were determined after storage for 7 days and after removal of the volatile and transfer to 22°C for 3 days. Fruit harvested at the ripe stage were inoculated with 106 conidia B. cinerea per ml and were placed in plastic containers containing no volatile compound (control) or two quantities of (E)-2-hexenal (10 or 100 μl). (E)-2-hexenal diethyl acetal (30 or 300 μl), benzaldehyde (30 or 300 μl), or methyl benzoate (12 or 60 μl). The fruit containers were overwrapped with a low-density polyethylene film, sealed, stored at 2°C for 7 days, and then transferred to 22°C for 3 days. Aerobic, microaerophilic, and coliform populations of fruit exposed to volatile compounds tended to be lower than the controls after storage at 2°C for 7 days and, depending on the volatile compound, similar, lower, or higher than the controls after transfer and storage at 22°C. However, due to variability in initial aerobic, microaerophilic, and coliform populations of the fruit used in the differential trials (P < 0.05), none of the differences between control and treatment and between treatments within a sample time were significant (P > 0.05). Strawberry fruit exposed to 100 μl of (E)-2-hexenal was the only treatment that did not show a significant increase in mold populations after transfer and storage at 22°C for 3 days. Additional studies are needed to determine if (E)-2-hexenal can be used in combination with other postharvest storage conditions, such as low temperature and controlled/modified atmosphere, to delay mold spoilage and extend the shelf life of the strawberry.