Efficacy of active modified atmosphere packaging containing thymol on fortification of antioxidant capacity and reducing the microbial contamination of pomegranate arils

Abstract

Pomegranate arils pose a significant challenge when it comes to preserving their nutritional value and preventing microbial contamination. This study aimed to explore the impact of thymol fumigation and active modified atmosphere packaging (MAP) on enzymatic activity and microbial contamination prevention in pomegranate arils. The results indicated that arils stored in a high O₂ atmosphere (HO₂A) with thymol had notably different catalase (CAT) and peroxidase (POD) activity levels compared to other treatments. These arils exhibited the highest CAT activity and the lowest POD activity. The highest phenylalanine ammonia-lyase (PAL) activity was observed in arils stored in HO₂A with thymol, although it was not significantly different from those stored in a high CO₂ atmosphere (HCO₂A) with thymol (P<0.05). Arils stored in a low oxygen atmosphere (LO₂A) and HCO₂A with thymol showed the highest polyphenol oxidase (PPO) activity levels, while arils in HO₂A with thymol had the lowest. The HO₂A with thymol treatment resulted in the lowest presence of psychrophilic bacteria, although it was not significantly different from arils stored in LO₂A with thymol (P<0.01). Based on cluster analysis results, HO₂A with thymol, LO₂A with thymol, and HCO₂A with thymol could be considered the most effective treatments for extending the storage life of packaged pomegranate arils.