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

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.