STUDY OF THE QUALITY OF VEGETABLE OILS UNDER DIFFERENT STORAGE CONDITIONS

The objective of this study was to evaluate the quality of vegetable oils: unrefined sunflower oil (Grade I) and hydrated soybean oil (Grade I). One of the key phases of the analysis involved determining quality indicators, including acid value (representing the total content of free fatty acids) and peroxide value (indicating the amount of primary oxidation products of fats – peroxide compounds). The oxidation degree of fats was evaluated by determining the peroxide value, titrating the released iodine with a sodium thiosulfate solution, and by measuring the acid value using the neutralization (titration) method with an alkali and an indicator. Each experiment was performed five times. Initially, fresh oil samples were analyzed, and after three months of storage under different conditions (both recommended and non-recommended), these indicators were reassessed. The results demonstrated that the fresh oil samples met the requirements of state standards (DSTU EN ISO 660:2009; DSTU 4570:2006), confirming their high quality and adherence to production and transportation conditions. In samples stored for three months under recommended conditions, increases in acid and peroxide values were observed but remained within acceptable limits. In contrast, samples stored without following recommended conditions showed significant increases in these values, exceeding the acceptable standards, thereby indicating a decline in quality.This research emphasizes the importance of adhering to recommended storage conditions to ensure the quality of vegetable oils.