Effect of perforation-mediated modified atmosphere packaging and storage duration on physicochemical properties and microbial quality of fresh minimally processed 'Acco' pomegranate arils

This study investigated the effects of number of perforations (P-0, -3, -6 and -9 per 160.1 cm2) and storage duration on the physicochemical quality attributes and microbiological quality of fresh minimally processed pomegranate (Punica granatum L., cv. Acco) arils stored at 5 °C for 15 days. Arils were analysed for physicochemical quality attributes on day 0, 3, 6, 9, 12 and 15. Microbial analyses for aerobic mesophilic bacteria, yeast and moulds were made on 0, 6, 10 and 14 day, and the presence of Escherichia coli was tested before and at the end of storage. Headspace gas composition was significantly influenced by number of perforation. Highest CO2 accumulation was observed in non-perforated MAP, while O2 concentration increased with increase in number of perforations in PM-MAP. Highest decrease in total soluble solids (TSS) from 15.4 to 13.1°Brix was observed in P-9 PM-MAP arils. Highest counts of aerobic mesophilic bacteria (5.5 log CFU g−1) and yeast and moulds (5.3 log CFU g−1) were observed in P-0 and P-9 PM-MAP. No E. coli were detected before and at the end of storage. Overall, P-3 and P-6 PM-MAPs better maintained quality attributes of pomegranate arils than P-0 and P-9.