Evaluation of the Antioxidant Capacity of a Guarana Seed Extract on Canola Oil Lipid Stability Using Accelerated Storage

Abstract

This study evaluates the antioxidant ability of hydroethanolic (40:60, water:ethanol, v/v) guarana seeds extracts (GSE), compared to the synthetic butylated hydroxytoluene (BHT), in the lipid oxidation evolution of canola oil, using an accelerated storage test (16 days at 60 °C). Canola oil is stabilized by GSE addition (200–1000 ppm) and following the peroxides, p‐anisidine, or conjugated dienes values, a higher stabilization is observed for 800 or 1000 ppm compared to the dose of 200 ppm. Thiobarbituric acid reactive substances increase from 0.57 to 4.56 mg MDA kg−1 after 16 days (control), while no significant differences are observed with GSE (1.51–1.87) compared to BHT (1.57 mg MDA kg−1). The effect of GSE addition to canola oil on individual fatty acids shows that the PUFA contents decrease significantly without GSE, 24.6 versus 28.2 g/100 g of FAMEs, respectively, but not with GSE at 600–1000 ppm. The observed impact of GSE (200–1000 ppm) in stabilizing canola oil is comparable to BHT at 200 ppm, GSE being of great interest as a natural additive with high antioxidant activity over synthetic antioxidants.Practical Application: The addition of guarana seed extracts (GSE) to canola oil is a useful strategy to reduce lipid oxidation of this oil, as well as to preserve its polyunsaturated fatty acids when antioxidants are not added. Moreover, the utilization of GSE is of great interest as a natural antioxidant over butylated hydroxytoluene (BHT), thus reducing the amount of synthetic antioxidants to be used.Evaluation of the antioxidant ability of guarana seeds extracts (GSE), compared to the synthetic butylated hydroxytoluene (BHT), in the lipid oxidation evolution of canola oil, using an accelerated storage test (16 days at 60 °C).