RÉSUMÉ
Onions are always in high demand owing to various culinary as well as health protective properties and these days there is increased consumer preference for ready-to-eat or ready-to-cook onions. In this context, the current study was aimed to extend the keeping quality of minimally processed onions for an extended period while ensuring microbial safety as well as sprouting inhibition through an integrated approach. The optimized combinatorial approach included gamma radiation treatment (Dmin60 Gy), minimal processing (de-skinning and scooping) and packaging in trays wrapped with polypropylene (PP; 10 µm thick) film followed by storage at low temperature (4-6 °C, relative humidity RH 65-70%). The parameters like shelf life, physico-chemical (colorimetry, moisture), organoleptic and nutritional properties were comprehensively assessed and found to be well retained up to 30 days with moisture loss of ≤ 5% and overall acceptability rating of 7 on 9-point hedonic scale. Microbiological analyses confirmed absence of Salmonella spp in these stored onions thus ensuring microbial safety. Nutritional profiling including carbohydrate, protein, fat, energy, and ash content revealed no significant change due to the processing as well as during storage. Thus, the radiation processing of freshly harvested bulbs followed by minimal processing, packing in formulated package and storage under low temperature conditions were found acceptable up to 30 days in the ready-to-eat form. Current findings provide credible evidences ascertaining extended shelf-life as well ensuring microbial safety of processed onions for commercial utilization by the food industries.
RÉSUMÉ
Freshly harvested and well-suberized potato (Solanum tuberosum) of varieties Kufri Jyoti, Lady Rosata, Kufri Laukar, and Hermises were processed by radiation at 78/149 Gy (D(min)/D(max)) dose and stored at 12 +/- 2 degrees C for 8 mo from March to October for assessment of chip-making quality. The firmness of the tubers in all the varieties processed remained unchanged during the period of storage. Chips of the desirable quality could be prepared from 7-mo stored Lady Rosata, Hermises, and Kufri Jyoti varieties, whereas, in Kufri Laukar, the quality chips could be prepared with tubers stored not beyond 5 mo. In the present study, varietal differences were found to influence the chip-making quality of irradiated potato. Tubers with high reducing and total sugar (>2%) were found to be unsuitable for chip-making. The quality of chips, however, was not affected much by the change in internal color of the tuber during storage beyond 6 mo. The results suggested the efficacy of gamma irradiation for ensuring availability of the processing quality potato during lean periods from September to October.