RE-COOLING OF STRAWBERRIES AFTER AIR SHIPMENT DELAYS FRUIT SENESCENCE

Abstract

The objectives of this work were to evaluate the effect of temperature abuse during a simulated air-cargo shipment on the quality of strawberries and to determine the most appropriate cooling method to be used following air-shipment in order to reduce fruit quality loss. Freshly harvested 'Kent' strawberries (Fragaria x ananassa Duch.) were room cooled to 4°C within 4 h immediately after harvest. Fruit were then packed in 0.47-L plastic clamshell containers and stored at 20°C and 60-70% RH for 20 hours to simulate time delays, temperature and humidity typically encountered during air-shipment. After that period, the strawberries were either forced-air re-cooled at 0°C, room re-cooled at 0°C, or held at 20°C to simulate different facility conditions available at the airports. After re-cooling, the fruit were transferred to 0°C and 85-90% RH. Fruit quality was evaluated after harvest, after air-shipment, after re-cooling treatment, and after 6 and 10 d of storage. Temperature abuse resulted in increased weight loss, darkening and toughening of the fruit, and decreased titratable acidity and soluble solids and anthocyanin contents. Results pointed out that re-cooling after temperature abuse was beneficial in maintaining strawberry quality compared to not re-cooling. Forced-air re-cooling to re-cool temperature-abused strawberries while in transit at the airport and/or after air shipment did not provide an advantage over room re-cooling at 0°C.