Decay control of "Femminello Santa Teresa" lemon fruits by prestorage high temperature conditioning

Marketing quality and juice chemical parameters of late harvested "Femminello Santa Teresa" lemon fruits (Citrus limonBurm), wrapped with a 15 mm heat shrinkable film or left unwrapped, and then either conditioned at 36°C for 72 hours in a 85-90%, relative humidity (RH) atmosphere or not conditioned, were determined over 3 months storage at 6°C and 95% RH or after 1 week at 20°C and 75% RH following each month of storage. Conditioning significantly reduced the incidence of decay caused byPenicillium digitatum, but not that due to other pathogens, such asBotrytis cinereaandAlternaria citri, especially in combination with film wrapping. Positive was the effect of heating in ameliorating the physiological response of lemon fruit to low temperature, although the beneficial effect appeared to be time-dependent, in fact at the end of the storage period severe symptoms of chilling injury were also noticed in conditioned fruit. No differences were instead observed in chilling sensitivity between conditioned and nonconditioned wrapped fruit. Weight loss was higher in conditioned fruit than in non conditioned one. Regarding chemical parameters, either conditioning or fi1m wrapping hastened the rate of degradation of acidity, total soluble solids (SST) and vitamin C.