COMPARATIVE OXIDATIVE STABILITY OF SOYBEAN ANDSUNFLOWER OIL DURING PROLONGED STORAGE UNDER VARIOUSSTORAGE CONDITIONS

This study assessed the oxidative stability of soybean and sunflower oils over an 8-week storage period in both dark and light conditions, using acid value (AV), free fatty acid (FFA) content, peroxide value (PV), and saponification value (SV) as indicators.Both oils quickly exceeded the acceptable AV limit of 0.6 mg KOH/g, showing rapid degradation.Soybean oil's AV rose from 0.87 (dark) and 0.67 (light) to 2.10 and 2.60, respectively, while sunflower oil's AV increased from 0.89 (dark) and 0.67 (light) to 2.29 and 2.75.FFA content also surpassed the 1% limit, with soybean oil reaching 1.05% (dark) and 1.3% (light), and sunflower oil reaching 1.15% (dark) and 1.38% (light).PV indicated significant oxidative degradation, especially in light, with soybean oil's PV rising from 0.15 meq O2/kg (dark) and 0.22 meq O2/kg (light) to 3.74 and 11.3 meq O2/kg, respectively.SV values also exceeded acceptable ranges.Correlation analysis revealed strong positive relationships between AV and PV, AV and FFA, and moderate correlations between SV and AV, and SV and PV, emphasizing interconnected hydrolytic and oxidative degradation processes.The study found sunflower oil degrades faster than soybean oil, particularly under light exposure, due to its higher polyunsaturated fatty acid content.