EFFECT OF SOME POSTHARVEST TREATMENTS ON IMPROVING QUALITY AND STORABILITY OF PERSIMMON FRUITS DURING COLD STORAGE

Abstract

persimmon is an important seasonal fruit which often exhibits rapid softening during postharvest distribution, handling or sometimes on the trees. Storage treatments and packaging types are critical points on degradative pathways of bioactive components reflected to fresh fruits quality properties. The present investigation was conducted during two successive seasons (2015 and 2016) on persimmon (Diospyros kaki L.) fruits c.v. “Costata”. Fruits were harvested at maturity orange color and were divided into two groups, the first group was dipped in hot water at 50oC for 10, 20 and 30 min., while the The second one was dipped in edible coating film consists of (10g maltodextrin, 5g methyl cellulose, 8ml glycerol, 2.5g ascorbic acid, 1g potassium sorbate and 1g calcium chloride/ distilled water liter) for 10, 20 and 30 min., in addition to the untreated fruits (as control). Fruits of all treatments were stored at 4±1◦C and 90% relative humidity (RH) in polyethylene terephthalate (PET) punnets for 8 weeks. The changes in physical and chemical properties of fruits were evaluated as fruits color, weight loss, firmness, total soluble solids (TSS) and titratable acidity percentage also antioxidant components (total phenols, total tannins, flavonoids, ascorbic acid and carotenoids) were studied during storage period every two weeks. The obtained results illustrated that all fruits had storage life eight weeks at cold storage 4±1◦C and 90% relative humidity (RH), fruits treated with edible coated film for 30 mins. have gained best quality in comparison with other treatments its. Since, it’s observed delayed in increasing total soluble solids percentage, reduced titratable acidity percentage and fruits firmness. On the other hand, the decrement of antioxidant contents including ascorbic acid, total phenols, flavonoids, were higher in persimmon fruits treated with hot water and control.Therefore, some postharvest treatments such as hot water or edible coating film to improve fruits sensorial quality through reducing the astringency and bitterness components in persimmon