Effect of Minimal Processing and Modified Atmosphere Packaging on the Quality Characteristics of Onion (Allium Cepa L)

Abstract

The effect of minimal processing (MP) and Modified Atmosphere Packaging (MAP) on the shelf- life and quality characteristics of fresh-cut onions were evaluated. During the storage period of 2 weeks, the cut onion quality attributes were evaluated by way of  changes in total soluble solids (TSS),  pH, moisture content, color values (hunter colour) and  sugar content. The product was also tested for microbial profile and sensory acceptability during and after the storage period  of 14 days. During the storage period, there was a slight increase in moisture content and a decrease in both pH and TSS values.  Similarly, there was an overall decrease in the sugar content of the stored MP onion. The minimally processed onions packed in Polypropylene (PP) bags of 37microns thickness had a shelf life of ~14 days at 4±2°C retaining all quality attributes, having microbial load within the threshold level (log 6) and had sensory acceptance. It was found that cut onions, which were packed in passive modified atmosphere without pretreatment, lost their sensory attributes at the end of the storage period of 14 days ie., overall quality score for control was 6.5 and for sample that were pretreated and packed under MAP conditions, the sensory score was 8.0.