The effect of packaging materials and storage condition on the oxidative stability of refined sunflower oil

Abstract

In this research, refined sunflower oil was packed at various packaging materials namely: yellow PET (polyethylene terephtalate) bottles, clear PET bottles, yellow HDPE (high density polyethylene) containers and metal cans. Randomly selected packaged sunflower oils samples were packed in carton as dark condition and secondary container. The samples were stored at room temperature (26.9°C) for 365 days. At 45 days intervals, the peroxide values of stored samples were determined. Every 180 days the samples were analyzed for TBA and anisidine values. In order to determine the effect of storage temperature, some samples were stored at 38°C under dark condition for a period of 56 days. At 7 days intervals, the peroxide value of samples was determined. The results indicate that at room temperature, increase in peroxide value, thiobarbituric acid (TBA), anisidine value and totax value were significantly (p < 0.05) higher in sunflower oil stored in HDPE containers as compared to PET (yellow, clear) bottles and metal cans. No significant differences were observed in the capability of PET bottles and metals cans to protect the oil against the deterioration effect of primary and secondary oxidation. At 38°C, significant differences on peroxide value of sunflower oil in HDPE containers in comparison to the other packaging materials were observed (p < 0.05). The results indicate that, the estimated shelf life for sunflower oil in HDPE containers at room temperature were less than 180 days and decreased to 35 days at 38°C. Where as, the shelf life of sunflower oil in PET (yellow, clear) bottles and metal cans were estimated to be more than 365 days at room temperature. It seems that PET bottles and metal cans are suitable containers for sunflower oil that protect oil against oxidative deterioration, where as the HDPE container with the low oxidative stability is unsatisfactory.