Increasing Cold Tolerance of Cactus Pear Fruit by High-Temperature Conditioning and Film Wrapping

Pre-storage high-temperature conditioning (HTC, 38 A degrees C, and 95% RH for 24 h) and individual film wrapping (IFW) with a perforated polyolefinic heat-shrinkable film were used as individual treatments or in combination to mitigate chilling injury of first crop cactus pear cv 'Gialla'. The fruit was stored for 21 days at either 2 or 8 A degrees C (CS) plus 1 week of simulated marketing conditions (SMC) at 20 A degrees C. The reduction in peel disorders and decay in HTC-treated fruit stored at 2 A degrees C was comparable to that detected in control fruit stored at 8 A degrees C. IFW was more efficient than HTC in reducing peel disorders, almost completely inhibited weight loss, and preserved freshness in fruit stored at 8 A degrees C as well as in those stored at 8 A degrees C. The internal quality of the fruit (pH, total soluble solids, titratable acidity, vitamin C, polyphenols, betaxanthins, antioxidant capacity, acetaldehyde, and ethanol) was slightly affected by treatments. Combining HTC with IFW did not improve fruit tolerance to low temperature but reduced decay with respect to individual treatments. IFW with a perforated film in combination with HTC is a good means of overcoming the stringent conditions of cold quarantine treatments, maintaining fruit freshness and reducing decay in cold-stored cactus pears.