Chilling injuries in peaches during conventional and intermittent warming storage

Abstract

Firm-breaker and firm-mature peaches ( Prunus persica L. Batsch cv. ‘Paraguayo’) were conventionally stored for 4 weeks at 2°C and 90–95% relative humidity or subjected to intermittent warming cycles of 1 day at 20°C every 6 days of storage at 2°C. Warming periods induced ripening (reduced flesh firmness, extractable juice and titratable acidity), while during continuous storage abnormal values of these parameters were found. After 2 weeks at 2°C and particularly after the subsequent 3 days at 20°C, woolliness and to a lesser extent, vitrescence and dryness of the cortical tissue were detected. Severe levels of these disorders were found more frequently in firm-breaker than in firm-mature fruits, which mainly developed vitrescence. Three cycles of intermittent warming prevented chilling injuries but increased weight loss and senescence symptoms. Compared with conventional storage, intermittent warming increased the shelf-life of firm-mature and firm-breaker peaches by 1 and 2 weeks, respectively. Some considerations on the commercial application of the intermittent warming technique are included.