Pomegranate seeds as a source of nutraceutical oil naturally rich in bioactive lipids

Pomegranate seed oil is constituted primarily of the rare conjugate linolenic acid (punicic acid), whose activities against inflammation and metabolic syndrome have been confirmed in various in vivo experiments. Because of this, the lipid composition of pomegranate seeds, representing one of the principal by-products of the pomegranate juice industry, was analyzed. After juice production, the lipolytic enzymes present in the pomegranate seeds were inactivated by thermal treatment. Total lipid content of the pomegranate seeds varied between 7.9 and 16 %. The pomegranate seed oil contained large amounts of conjugated linolenic acids (CLnA), such as punicic acid, in the range of 74-85 % of the total fatty acid content. Other major fatty acids were oleic, linoleic and palmitic acid, respectively. Pomegranate seeds also showed high contents of tocopherols; one of them, γ-tocopherol, was 87.9-95.0 % of the total tocopherols. Moreover, two tocotrienols were identified for the first time in pomegranate seed oil. The major phytosterols analyzed were campesterol, stigmasterol, sitosterol, δ5-avenasterol and citrostadienol. Furthermore, some triterpene compounds such as cycloartenol, 24-methylene-cycloartenol and betulinol and squalene were quantified. Three different phospholipids were detected; phosphatidylethanolamine was the principle compound, accounting for 56-86 % of total phospholipids.Briefly, these data promote pomegranate seeds as rich sources of bioactive lipids with potential beneficial physiological activities and encourage their use in human nutrition.