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Florida peaches (Prunus persica) typically are picked and placed in a cold room on the day of harvest, then packed and shipped the next day. This room cooling (RC) is slow, requiring ≈24 hours or more for the fruit to reach optimal temperature (6 to 7 °C). There is currently limited research on the effect of cooling practices on microbial quality of peaches, yet this study is essential for decision making in areas such as upgrading packing house facilities and the implementation of improved handling procedures. This research compared the efficacies of postharvest cooling by RC, forced-air cooling (FAC), and hydrocooling with sanitizer (HS) treatment of peaches to reduce their surface microbial population and to determine the effect on shelf life and microbial quality. Three trials for RC and two trials each for FAC and HS were performed. Following cooling, fruit were stored at 1 °C. The average aerobic plate count (APC) from field samples was 5.29 log cfu/peach, which remained unchanged after RC or FAC but was reduced significantly (P < 0.05) to 4.63 log cfu/peach after HS. The average yeast and mold counts (Y&M) from field samples (6.21 log cfu/peach) were reduced highly significantly (P < 0.001) to 4.05 log cfu/peach after HS. Hydrocooling significantly (P < 0.05) reduced the APC and Y&M counts from the peaches and showed promise in maintaining the microbiological quality of the fruit throughout storage. However, at the end of the 21-day storage period, there was no significant difference in APC or Y&M counts from peaches, irrespective of the cooling methods. Peaches that went through the hydrocooling process and were subsequently packed showed an increase (P < 0.05) in both APC and Y&M counts, while fruit that were not hydrocooled showed no such increase. Information obtained will be used to recommend the best temperature management practices for maintaining the postharvest quality of peaches. A detailed cost-benefit analysis of different cooling methods and the time interval between harvest and shipment are both necessary for a more conclusive recommendation.

Cooling procedures used by blueberry (Vaccinium sp.) growers often may include delays up to 24 hours that can damage the fruit through rough handling and adverse temperatures, thereby potentially compromising quality and, subsequently, safety. The objectives of this experiment were to compare forced-air cooling (FAC) compared to hydrocooling without sanitizer (HW) and hydrocooling with sanitizer (HS) regarding the quality and shelf life of southern highbush blueberry [SHB (Vaccinium corymbosum)] and to determine the efficacy of these treatments for reducing Salmonella in SHB. Freshly harvested SHB that were inoculated with a five-serovar cocktail of rifampin-resistant Salmonella were rapidly chilled by FAC or hydrocooling (HW and HS) using a laboratory model system. FAC did not show any significant reduction (P > 0.05) in Salmonella or in the effects on the microbiological quality of blueberries. HW and HS reduced Salmonella by ≈2 and >4 log cfu/g SHB, respectively, on day 0. These postharvest treatments were also evaluated for their ability to help maintain fruit quality throughout a storage period of 21 days at 1 °C. Hydrocooling (both HS and HW) provided more rapid cooling than FAC. Hydrocooled blueberries showed significant weight gain (P < 0.05), whereas FAC resulted in a slight, but insignificant (P > 0.05), reduction in final weight. The results of hydrocooling, both HS and HW, shown in this study could help to extend the shelf life while maintaining or increasing the microbiological quality of fresh market blueberries. Information obtained by this study can be used for developing the best temperature management practices to maintain the postharvest safety and quality of blueberries.