EFFECTS OF WET HEAT TREATMENT (WHT) DURATIONS ON THE QUALITY OF SWEET ORANGE STORED AT ROOM TEMPERATURE

The experiment on “effect of wet heat treatment (WHT) durations on the quality of sweet orange stored at room temperature” was conducted at the Agricultural University, Peshawar during the year 2006-07. The fruits were subjected to wet heat treatments for 0-20 minutes and stored at room temperature for 0-75 days. Storage significantly increased weight loss, peel puncture pressure, TSS, acidity, reducing sugars and disease incidence but declined the rind moisture non-reducing sugars and ascorbic acid contents. The modest wet heat treatment (5-10 minutes at 50°C) retarded the storage associated changes in sweet oranges but extended heat treatments (15-20 minutes), reversed the beneficial effects and enhanced the decline in physical and chemical quality attributes. Ascorbic acid, however, continued to decrease even with modest heat treatment.