Potato peel extract as a natural antioxidant in chilled storage of minced horse mackerel ( Trachurus trachurus): Effect on lipid and protein oxidation

► Effectiveness of potato peel on protein and lipid oxidation in fish mince was examined. ► Ethanol extracts prevented both lipid and protein oxidation. ► Water extract was less efficient and showed pro-oxidative nature at high concentrations. The present work was undertaken to examine the utilisation of potato peel, a waste material, as a source of natural antioxidants for retarding lipid and protein oxidation in minced mackerel. Mackerel mince with two different concentrations (2.4 or 4.8 g/kg) of water or ethanol extracts of potato peel and a control with no added extracts were prepared. The samples were stored at 5 °C for 96 h and the sampling was done at time points 0, 24, 48 and 96 h. The ethanol extracts, which contained high amounts of phenolic compounds, was found to be very effective in retarding lipid and protein oxidation as it resulted in low levels of peroxide value, volatiles, carbonyl compounds and protected against the loss of α-tocopherol and tryptophan and tyrosine residues. Water extracts was less efficient especially at higher concentrations, which might be due to lower phenolic content or due to the pro-oxidative nature of some of the phenolic acids/co-extracted compounds.