Effect of storage temperature on ripening and quality of custard apple (Annona squamosa L.) fruits

The effect of storage temperature on ripening, shelf Life and chemical comp osition of custard apple (Annona squamosa L.) fruits stored at 10, 15, 20 a nd 25 degrees C was studied. The safe range of storage temperature was foun d to be between 15 and 20 degrees C, with maximum shelf life at 15 degrees C. The ripening of fruits was observed on days 4, 6 and 9 of storage at 25, 20, and 15 degrees C respectively. The colour of the pulp, texture, taste and flavour of ripe fruits held at 25 and 20 degrees C were superior follow ed by fruits stored at 15 degrees C. At 10 degrees C, the fruits became har d with surface blackening, messy pulp and less sweetness. The major changes during ripening were a continuous decrease in fruit firmness and starch co ntent and a continuous increase in TSS and sugars, the changes being more r apid at 25 and 20 degrees C than at 15 and 10 degrees C. The acidity and as corbic acid contents increased slightly during the initial stages of ripeni ng followed by a decline, in the fruits stored at different temperatures. C ustard apple fruits stored at 25 and 20 degrees C had a clear climacteric p eak whereas those stored at 15 and 10 degrees C did not show any distinct r ise in respiration rate. Ethylene peak (2.40 mu l kg(-1) h(-1)) coincided w ith the respiratory climacteric at 25 degrees C storage, corresponding with the peaks in TSS, sugars, ascorbic acid and acidity.