Pyramided effects of γ‐irradiation, packaging, and low‐temperature storage on quality, sensory and microbial attributes of minimally processed onion rings.

Minimally processed onion rings in different packages treated with gamma irradiation (0.5–2.5 kGy) were studied for shelf‐life extension under low temperature (Temp 4–5°C, RH 60%–70%). An untreated sample at 0 kGy was considered as the control sample. The quality, sensory, and microbial attributes of minimally processed onion rings were recorded at 5 days intervals for 30 days. Both gamma irradiation and packaging treatments significantly (p <.01) effect the firmness, color, physiological loss in weight, total soluble solids (TSS), ascorbic acid, pyruvic acid, and total plate count. Losses in weight and texture were found to be higher in vacuum packaged onion rings and increased with an increase in storage duration. The TSSs content in onion rings increased with an increase in storage period with the highest increase in vacuum packages. The lowest microbial load in onion rings was maintained in polypropylene packages with perforations in all the gamma‐irradiation treatments but physio‐chemical quality decreased at the dose level of 2.5 kGy. Overall acceptability of onion rings irradiated at 1.5 kGy obtained the highest scores irrespective of packaging treatment. Thus, polypropylene packaging with perforations and a gamma dose of 1.5 kGy was found to be most suitable for maintaining the shelf life of minimally processed onion rings. Practical applications: Minimally processed onion rings packed in perforated polypropylene packs and treated with gamma irradiation is cost‐effective and safe and convenient to use as there is no application of chemical and preservatives. Besides, the shelf life of this product is maintained best for 20 days (with good overall acceptability) at refrigerated storage. These minimally processed onion rings could encourage several food industries to utilize them in various food products. This will also allow the onion processing industry to flourish. [ABSTRACT FROM AUTHOR]