Evaluation of antioxidants on oxidative stability and fatty acid profile of poultry offal oil used in the pet food industry

Abstract

The current study aimed to evaluate the use of antioxidants on the oxidative stability of poultry oil used in the pet food industry. Five synthetic commercial antioxidants and two natural ones were used: Control (CON); CON + (BHT+BHA+ETO95); CON + (BHT+BHA); CON + (BHA+PG+AC); CON + (BHT+BHA+ETO70); CON + BHA; CON + (ASC+ Rosemary); CON + (ASC+ Tocopherols)). The inclusion was 0.5% for synthetics antioxidants and 0.625% for natural antioxidants. The determination of oxidative stability was done in three temperatures (90 ° C, 110 ° C and 130 ° C). For the determination of the fatty acid profile, the original sample of the poultry oil was considered as a negative control. The determination of the fatty acids was based on the preparation of the methyl esters by transesterification reaction with methanol in an alkaline medium, followed by analysis by gas chromatography. The identification of the different fatty acids was obtained by comparing the retention times of standards of fatty acid methyl ester with retention times of peaks observed. An analysis of compositional data was performed. It was possible to observe that, without using a reliable antioxidant, the induction time is shorter, resulting in a lower oxidative stability of the viscera oil, with consequent loss of its quality, due to less time spent to oxidize. The antioxidants used in CON + (BHT + BHA + ETO95), CON + (BHA + PG + AC) and CON + BHA, preserved more essential fatty acids (linolenic and linoleic). Natural antioxidants had higher oxidation, with higher proportions of saturated fatty acids and the worst ?6: ?3 ratios. It is concluded that the synthetic antioxidants used in CON + (BHT + BHA + ETO95), CON + (BHA + PG + AC) and CON + BHA provided greater protection against oxidation and better preserved essential fatty acids. Natural antioxidants, in the present study, did not present satisfactory protection.