Effect of pink pepper (Schinus terebinthifolia Raddi) on oxidative processes and β-sitosterol degradation in refined soybean oil during natural light exposure

Abstract

This study assessed the antioxidant effect of pink pepper (PP) in refined soybean oil during 60 days of light exposure at room temperature. Lipid oxidation was evidenced by peroxide and thiobarbituric acid reactive substances (TBARS) analyses. However, oils containing 4% and 6% PP showed lower peroxide values and reduced TBARS formation than the control. Therefore, both parameters decreased as PP concentration increased. TBARS formation followed zero-order kinetics in control, while PP samples fit a second-order model, reflecting the antioxidant influence. After 60 days, β-sitosterol degradation reached 57.8% in the control, while PP (4% and 6%) reduced losses (24.1% and 24.8%) until day 45 compared with the control (37.9%). Liquid chromatography- high resolution mass spectrometry revealed the migration of compounds (biflavonoids, terpenes, anthocyanins) from PP into the oil, suggesting their contribution to the protective effect. These findings indicate that PP helps preserve soybean oil, offering a strategy for industry and consumers.