Postharvest of yellow passion fruit: effect of chemicals and storage temperature

This study aimed to evaluate the effect of chemicals and storage temperatures on the incidence of diseases and the physicochemical quality of yellow passion fruit. Fruits were harvested with 30% of the skin colored yellow and treated with different products: sodium dichloroisocyanurate (200 mg.L-1 of active chlorine), prochloraz (1000 mg.L-1), control (fruits not treated). Treatments were applied by immersion for three minutes. The fruits were packed in expanded polystyrene trays coated with PVC 17 mu m and stored at 15 and 25 degrees C, 55% RH for 10 days and analyzed periodically for: rot incidence, skin color, soluble solids, titratable acidity and ascorbic acid content. After five days of storage the visible stem mycelial growth was higher in fruits stored at 25 degrees C than at 15 degrees C. The fungicide prochloraz reduced the appearance of rots after ten days of storage fruit. The main fungal genera found in the stems were Cladosporium, Alternaria and Fusarium. Reduction of acidity was observed on the tenth day of storage, and found lower levels of acidity in fruits at 25 degrees C. Regarding the skin color, reduction in the angle of color during storage indicating yellowing of skin, and the fruits stored at 25 degrees C showed a lower angle of color. The levels of ascorbic acid in fruit decreased approximately 10% during storage. The "ratio" (soluble solids: acidity) increased during storage, being higher in fruits at 25 degrees C, due to lower acidity. It is concluded that prochloraz was effective in controlling rots and that the use of chemicals not influence the physicochemical quality of packaged fruits. Changes of physicochemical characteristics were observed depending on temperature and time of storage.