The effects of pomegranate peel extract (PPE) added to ice on the quality and shelf life of horse mackerel (trachurus trachurus) under cold storage conditions (4±1°c)

Abstract

In this study, the effects of pomegranate peel extract (PPE) incorporated into ice on the quality and shelf life of horse mackerel (Trachurus trachurus) under cold storage conditions (4 +/- 1 degrees C) were investigated. The primary objective was to assess the impact of PPE on various quality parameters throughout the storage period. Two experimental groups were established: a control group (C) and a PPE-treated group. The control group was stored with conventional ice, whereas the PPE group was stored with ice enriched with pomegranate peel extract. To evaluate the differences between the groups, a comprehensive set of physicochemical (proximate composition, pH, water activity, color, TBA, TVB-N), microbiological (TAMB, TAPB), and sensory quality analyses were conducted. By the end of the storage period, the TVB-N value reached 19.00 +/- 0.43 mg N/100g in the control group, while it remained significantly lower at 12.67 +/- 0.3 mg N/100g in the PPE-treated group. Similarly, the initial TBA value of 0.39 +/- 0.04 mg MA/kg increased to 5.84 +/- 0.19 mg MA/kg in the control group, whereas it only reached 1.64 +/- 0.20 mg MA/kg in the PPE group, indicating a substantial reduction in lipid oxidation. From a microbiological perspective, both groups remained below the critical threshold of 7 log cfu/g for total psychrophilic and mesophilic aerobic bacteria throughout the storage period. However, the PPE-treated group exhibited a notably lower bacterial load compared to the control, suggesting an antimicrobial effect of PPE. Color measurements (L*, a*, and b* values) were also monitored, revealing an increase in the b* value over time. However, this shift did not negatively impact sensory evaluations; on the contrary, the resulting yellowish hue was found to be visually appealing by the panelists. In the final sensory assessment, the control group was rated close to degraded fish quality, whereas the PPE-treated group was evaluated as being much fresher, underscoring the positive influence of PPE on fish quality. In conclusion, the application of PPE-enriched ice significantly extended the shelf life of horse mackerel by an additional five days under cold storage conditions. The strong antioxidant potential of pomegranate peel extract, functioning as a natural preservative, highlights its promising role in the long-term preservation of fishery products in similar applications.