Effect of prestorage curing on storage life, internal and external qualities of sweet orange (Citrus sinensis)

Abstract

-Orange fruits from two seasons, in April and August 2006 representing late 2005 and early 2006 harvests respectively were cured in hot air at 36-37 0 C to 1%, 3%, 5% and 7% weight loss before storage at 28 0 C and 86% relative humidity (RH). The fruits were observed for incidence of decay, further weight loss, juice content, firmness or softening of the peel, total soluble solids (TSS), pH, titratable acidity, and colour during storage. Curing reduced the incidence of decay. All control fruits were rotten by day 21 in August harvest while 22.5% of the control was rotten by day 56 in the April harvest. Storage life was extended beyond 56 days in fruits cured with 1, 3, 5 and 7% in April harvest as there was no decay throughout, while decay incidence in August harvest was 88.9, 61.1, 22.2 and 31.3% in 1, 3, 5 and 7% respectively. Penicillium digitatum, Phytophthora sp., Alternaria citri and Collectotrichum gloeosporioides were among decay causing moulds detected. Control fruits lost more weight during storage than cured fruits did. Fruit rind hardening was more noticed in the control and those cured to 1% weight loss, especially from the April harvest. It was insignificant in other treatments in both trials. Titratable acidity, pH, juice content and TSS were not affected by the treatment. Colour change to yellow was however retarded by curing. Curing to 5% weight loss was best for decay control and quality retention.

EFFECT OF POST HARVEST TREATMENTS ON SHELF LIFE AND QUALITY OF SWEET ORANGE (Citrus Sinensis) IN GAASC, GOKULESHWOR, BAITADIS

“…Weight loss was taken with the help of digital balance having capacity to weight from 1 mg to 5 kg. The formula used for the calculation was (Aborisade and Ajibade, 2010):…”