Effect of annatto powder and sodium erythorbate on lipid oxidation in pork loin during frozen storage

There are few reports about the antioxidant properties of annatto (Bixa orellana), especially considering their antioxidant action in food. In this study we evaluated the antioxidant effect of annatto powder and sodium erythorbate on lipid oxidation in pork loin patties by measuring the secondary products of lipid oxidation, the changes in the fatty acid composition, cholesterol oxidation, and the extent of bixin degradation during storage at − 18 °C for 120 days and subsequent thermal treatment. Sodium erythorbate (0.1%) and annatto (0.05%), used alone or in combination, were able to reduce the formation of thiobarbituric acid reactive substances and cholesterol oxidation after thermal treatment when compared with pork patties without antioxidant (control). Bixin degradation was less pronounced in the patties containing annatto (0.05%) + sodium erythorbate (0.1%), suggesting that sodium erythorbate protected this carotenoid from degradation. The addition of annatto, sodium erythorbate or annatto + sodium erythorbate did not have any impact on SFA, MUFA and PUFA oxidation regardless thermal treatment or storage. The cholesterol contents did not change during storage; however, there was a significant loss of 15% due to thermal treatment.