Physico-chemical changes during growth and development of papaya fruit. IΙ: Chemical changes

Chemical changes during growth and development of female and hermaphrodite fruits of 'Ekostika ', 'Ekostika II' and 'Baladi' papaya fruits were studied. Respiration curves exhibited a typical climacteric pattern. Respiration rate progressively declined to a minimum value at physiological maturity (120 DAA) and then increased in a climacteric pattern with peak of respiration at 140 DAA. Total soluble solid (TSS) and total sugars slightly increased up to physiological maturity and then sharply increased during the ripening phase (125-145 DAA). Reducing sugars, titratable acidity and total protein slightly decreased till physiological maturity and then increased, reaching a peak, which coincided with the climacteric peak of respiration, and subsequently decreased. Phenolic compounds progressively decreased and ascorbic acid content steadily increased. Papaya fruits should be harvested shortly (5-10 days) after physiological maturity, where the fruit attains maximum size and weight, still firm, climacteric rise phase has just started, TSS and sugars start to shoot up and phenolic compounds and acidity are reasonably low.