Effect of chilling exposure and vapor heat treatment duration on the quality of sweet orange during simulated marketing

Sweet orange fruits were exposed to vapor heat treatment (50°C) in water bath for 0, 5, 10, 15 and 20 min in plastic covered structure. The data were recorded on different physico chemical factors immediately after the storage and after seven days simulated marketing under ambient condition (20°C). Low temperature storage enhanced weight loss, surface pitting, disease incidence, total soluble solids accumulation, TSS/Acid ratio but decreased reducing sugars, acidity and ascorbic acid content. Chilling exposure up to 45 days had no significant effect on weight loss and TSS. However, increased weight loss (2.63%), TSS (11.75), TSS/Acid ratio (8.45 ºBrix), disease incidence (8.93%) and lowest reducing sugars (3.90) were noted in sweet orange exposed to chilling temperature for 75 days. Among the VHT durations, the highest weight loss (2.29%) was found in VHT for 0 min while the highest TSS (11.81 ºBrix), TSS/Acid ratio (8.10) and disease incidence (6.22%) and least reducing sugars (4.12%) were found in VHT 20 for min. Vapor heat treatment ranging from 5–10 min resulted in lowest weight loss (1.79%), TSS (10.81 ºBrix) TSS/Acid ratio (7.33), disease incidence (1.00%) and highest reducing sugars (4.75%) in sweet orange fruits. However, non-reducing sugars were least affected by both LTSs and VHTs. It is concluded that the chilling exposure (5°C) beyond 45 days aggravated the decline of fruit physio-chemical quality characteristics. Whereas, VHT with 5–10 min maintained the sweet orange fruit quality during simulated marketing; however, VHT of 15–20 min adversely affected the sweet orange fruit quality attributes.