Effects of EDTA and a combined use of nitrite and ascorbate on lipid oxidation in cooked Japanese sardine (Sardinops melanostictus) during refrigerated storage

To elucidate the effects of EDTA and a combined use of nitrite and ascorbate on oxidative rancidity of cooked Japanese sardine (Sardinops melanostictus) stored at refrigeration temperature (2 °C), changes in peroxide values (PV), thiobarbituric acid (TBA) value and fatty acid composition were monitored. The PV and TBA values of the meat with and without EDTA (250 mg/100 g meat) increased gradually, while they remained unchanged when a mixture of sodium nitrite (10 mg NO2/100 g meat) and sodium ascorbate (200 mg/100 g meat) was added. Total polyenoic acids in the nitrite and ascorbate mixture-treated meat decreased at a slower rate than in the control group. These changes in PUFA composition were due to differences in oxidative stability between the meats containing different antioxidants. In conclusion, a combined use of nitrite and ascorbate showed a greater antioxidativity in terms of the lower PV and TBA values than did EDTA and resulted in preventing the development of warmed-over flavour in cooked sardine during of 14 day refrigerated storage.