Oxidative stability and tocopherol content of refined sunflower oil during long-term storage in different commercial packagings

Abstract

The study was undertaken to monitor the changes in oxidative stability and �-tocopherol content of refined sunflower oil during 12 months of storage at room temperature in different commercial packagings: Tetra brick, polyethylene terephthalate (PET) bottles and polyethylene (PE) canisters. The results showed significant influence of packaging type on the oxidative stability of oil. The largest changes were determined in oil packed in PE canisters (volume 5 l), where the peroxide values (PV) after 12 months were 9.34 and 10.46 mmol kg –1 , while the lowest increase in PV were 1.05 and 1.67 mmol kg –1 in Tetra brick packaging. The highest increase in specific absorbances was also noticed for oil packed in PE canister. It came to loss of tocopherol during storage in accordance with the degree of oil oxidation. In oil packed in Tetra brick 6.52 and 8.14% losses of tocopherol (compared to the initial value) were found, while the losses in canister were found to be 14.18 and 17.88%. The results of Schaal-oven test also indicated decrease of oxidative stability during storage in accordance with protective properties of packagings and packing conditions.