Pomegranate (Punica granatum) peel fractions obtained by supercritical CO2 increase oxidative and colour stability of bluefish (Pomatomus saltatrix) patties treated by UV-C irradiation

Abstract

The sequential fractionation by supercritical-CO₂ (SC-CO₂) was applied to obtain fractions enriched in bioactive compounds of pomegranate peel, and we investigated if pomegranate peel extract and fractions would be effective to inhibit lipid and protein oxidation, and discolouration of bluefish patties stored at 4 °C for 9 days, after UV-C irradiation. The non-fractionated SC-CO₂ extract from pomegranate peel was rich in phenolic compounds, mainly ellagitannins, besides, it possessed lipophilic compounds such as tocopherols and β-carotene. These compounds were successfully separated by the fractionation protocols, in a lipid fraction concentrated in lipophilic compounds, and one or two fractions enriched with phenolic compounds, especially ellagitannins. The lipid fraction and the high phenolics fraction from pomegranate peel were then as effective as the synthetic antioxidant BHT in avoiding bluefish patties oxidation during refrigerated storage. Our data indicates that pomegranate peel fractions could be used to replace a synthetic antioxidant in fish meat.

Keywords: Butylated hydroxytoluene (PubChem CID 31404); Docosahexaenoic acid (PubChem CID 445580); Eicosapentaenoic acid (PubChem CID 446284); Ellagic acid (PubChem CID 5281855); Ellagitannins; Fruit by-product; Green technology; Marine fish; Natural antioxidant; Punicalagin (PubChem CID 44584733); Sequential fractionation; α-Tocopherol (PubChem CID 14985); β-Tocopherol (PubChem CID 6857447); β-carotene (PubChem CID 5280489); γ-Tocopherol (PubChem CID 92729).