Impacts of low and super-atmospheric oxygen concentrations on quality attributes, phytonutrient content and volatile compounds of minimally processed pomegranate arils (cv. Wonderful)

Abstract

This study investigated the impact of modified atmosphere (MA) storage: at low oxygen (O2) (MA-1; 5kPa O2+10kPa CO2+85kPaN2), (MA-2; 10kPa O2+5kPa CO2+85kPaN2); super-atmospheric O2 (MA-3; 70kPa O2+10kPa CO2+85kPaN2); and air (MA-4; 21kPa O2+0.03kPa CO2+78kPaN2) on the physicochemical, phytonutrient, volatile organic compounds (VOCs) and microbiological quality of minimally processed ‘Wonderful’ pomegranate arils stored at 5°C for 12 d. In addition, the effect of temperature fluctuation on the physical and microbiology quality of arils was evaluated. Samples were removed from cold storage on each sampling day, and kept for 2 d at ambient (20°C) condition. Low O2 atmosphere (MA-1) best maintained phytonutrient content of arils at 5°C. Aerobic mesophilic bacteria, yeast and mould counts were found to be significantly lower under super-atmospheric O2 (MA-3) storage in comparison to other treatments at 5°C and ambient. A total of 25 volatile organic compounds (VOCs) were detected and identified for pomegranate ‘wonderful’ across the different MA conditions. Highest relative composition of VOCs was found in samples stored under MA-3. Temperature fluctuation had a significant impact on the physical and microbiology quality of pomegranate arils.