Influence of postharvest hot-water dip and imazalil-fungicide treatments on cold-stored «di massa» lemons

The effectiveness of a 3-min postharvest water dip at 52°C or combined dips at 52 and 25°C, with and without the fungicide imazalil (IMZ), on peel pitting and mould decay control in cv. Di Massa lemons was investigated. A single dip at 25°C acted as control. Nine weeks of storage at 6°C and 10 days of simulated shelf-life at 20°C were the experimental conditions. More significant reduction of peel pitting and mould decay occurred with water dip at 52°C than at 25°C. The toxic effects on rind determined by IMZ at 52°C were prevented by double dip (water at 52°C followed by IMZ at 25°C). IMZmarkedly inhibited the development of rots in all experimental conditions. Less marked were the differences in the physiological (respiration rate and endogenous ethylene concentration) and internal quality parameters (ethanol and acetaldehyde concentration in juice, titratable acidity and total soluble solids) of fruit. A pre-storage water dip at 52°C followed by an IMZ dip at 25°C effectively control decay development in 'Di Massa' lemons without adversely affecting fruit quality characteristics.