Identification of some rancidity measures at the end of the shelf life of sunflower oil

Abstract

AbstractSunflower oil was stored at 40 °C, and changes in peroxide value (PV), anisidine value (AnV), thiobarbituric acid (TBA) value, iodine value (IV), conjugated dienes (CD) and hexanal (Hex) levels were monitored. Changes in the odor of samples during storage were assessed sensorially. Apart from IV, which decreased as storage progressed, the other chemical rancidity measures increased. Sensory shelf life data were adequately described by the Weibull distribution, with the 95% confidence interval of the nominal shelf life of sunflower oil, at 40 °C, being 9.04–10.45 wk. The chemical rancidity measures at the end of the sensory shelf life were: PV of 338–352.8 meq peroxide/kg, CD of 1.20–1.24% conjugated dienoic acid, AnV of 21.45–45, TBA values of 23.4–37, and Hex content of 4.79 mg/kg, while IV exhibited a decrease of 8.5–10%. The chemical measures of rancidity marking the end of the sensory shelf life provide objective indices for monitoring the shelf life of sunflower oil.