Stabilization of rose hip oil by pomegranate peel extract during accelerated storage

Rose hip seed oil is a rich source of polyunsaturated fatty acids, as well as tocopherols, carotenoids, sterols, phospholipids, and phenolic com­pounds. On the other hand, due to the high content of polyunsaturated fatty acids, this oil is prone to oxidation. The aim of this study was to investigate the influence of a natural antioxidant, i.e., pomegranate peel extract, and its com­bination with butylated hydroxytoluene as a commonly used synthetic anti­oxidant, on the stability of rose hip oil. The stability of samples without and with different antioxidants was monitored through analysis of the fatty acid composition and measurement of the quality and stability parameters of the oil (peroxide value, p-anisidine value, thiobarbituric acid reactive substances inhi­bition, total phenolic content and antiradical activity) during a storage period of 12 days at 65 °C. Pomegranate peel extract (0.1 %) inhibited more effectively the second stage of oxidation than butylated hydroxytoluene (0.02 %), while the first stage of oxidation was better prevented by the synthetic antioxidant. Furthermore, the addition of pomegranate peel extract increased the total phen­olic content of the rose hip oil as well as its antiradical activity. Thus, pome­granate peel extract could be used as a potent natural antioxidant for the stabil­ization of beneficial but unstable rose hip oil