Comprehensive fatty acids profiling of thirty Iranian pomegranate seed oil cultivars; oil stability and quality through various storage conditions

Abstract

Pomegranate seed oil (PSO) is recognized as a major by-product of the agro-food industry. This study evaluates thirty Iranian pomegranate cultivars with respect to their seed oil yield and fatty acid composition. Cultivars with the highest oil yields were selected for further analysis of oil stability and quality. Oxidative stability was assessed through standardized oxidation tests, and chemical changes were monitored using 1H NMR spectroscopy under various storage conditions. The findings revealed that punicic acid was the dominant fatty acid, while stearic acid was the least prevalent. 1H NMR analysis confirmed the isomerization of punicic acid (C18:3 9c, 11t, 13c) to β-eleostearic acid (C18:3 9t, 11t, 13t), caused by the conversion of cis bonds to trans under direct sunlight exposure. A notable degradation in oil quality was observed under oxidative conditions. Based on these results, storage at room temperature, protected from sunlight and air (to limit oxygen exposure), is recommended to maintain PSO quality. This study offers valuable insights into the potential of PSO as a functional food by-product and highlights essential technical considerations for its storage in the food industry.