Characterization of constituents, quality and stability of pomegranate seed oil (Punica granatum L.)

This study aimed to characterize pomegranate seed oil and evaluate its quality and stability parameters against those of linseed oil. The profile of fatty acids and phytosterols and the content of tocopherols were analyzed by gas chromatography and high performance liquid chromatography, respectively. The quality of both oils was assessed as recommended by the American Oil Chemists' Society (AOCS) and stability was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), beta-carotene bleaching (coupled oxidation of beta-carotene/linoleic acid) and Rancimat (R) assays. While a-linolenic acid (52%) was the most abundant fatty acid in linseed oil (LO), punicic acid (55%) was highest in pomegranate seed oil (PSO). Tocopherols and phytosterols (175 and 539 mg/100 g, respectively) were greater in PSO than in LO (51 and 328 mg/100 g, respectively). Both oils met quality standards. The beta-carotene bleaching and the DPPH assays showed greater oxidative stability for PSO than for LO. The Rancimat. method, on the other hand, indicated low stability for both oils.