The Effect of Packing Material on Storage Stability of Sunflower Oil

Abstract

Edible plant oils, including sunflower oil, with high content of unsaturated fatty acids, are subject to hydrolytic and oxidative deterioration during storage. This study investigates the impact of packing material, clear uncoloured glass bottles and clear uncoloured polyethylene terephthalate (PET) bottles, in which the refined sunflower oil was packaged, and impact of storage conditions, on the speed of oil deterioration. Oil was filled in the bottles, hermetically sealed and kept in a dry place, at room temperature, and illuminated by artificial light. Results of the oxidative stability of sunflower oil assessment during six month storing in controlled conditions, showed that photo-oxidation adversely has an affect on product quality characteristics and coses forming of primary oxidation products. Peroxide number in oil, immediately after bottling was 0,230 mmol O2/kg oil, while after 6 months of storage value reached 7,800 mmol O2/kg oil (in glass bottle), and 8,600 mmol O2/kg oil (in PET bottle). Anisidine number in oil immediately after bottling was 5,5 and after 6 months of storage in a glass bottle it was 39,6 and 57,40 when oil was packaged in PET bottle. Averages of total oxidation values in sunflower oil packed in glass and PET packaging increased from 5,5 (immediately after bottling) to 55,20 in oil packaged in glass bottle, and 57,40 in oil packaged in PET packaging. The other results obtained in the paper confirmed the need for protecting sunflower oil against oxidative spoilage during storage, providing packaging in colored packages and storing on dark, dry place.