Comparison of the effect of ultrasound and antioxidants application on the stability of fruit seeds oil.

The global fruit industry annually generates large amounts of by-products, many of which are underutilized or used only for animal feed. Blackcurrant and rose hip seeds are considered a by-product of fruit industry which may be processed to highly nutritive oil. The aim of this study was to compare the effects of ultrasound application in extraction process and a syntethicantioxidant (BHT) addition on the oxidative stability of rosehip and blackcurrant seed oils. Oils were obtained conventionally via solid-liquid extraction and by ultrasound-assisted extraction at various sonication times and intensities. The oils were subjected to analysis immediately after extraction and after 2 and 3 months of storage. The DSC, PDSC and GC analysis were performed for all of the oil samples. All oils were characterised by a high content of unsaturated fatty acids. The study determined differences in the oxidative stability of the oils between those with the addition of BHT and those obtained using ultrasound assistedextraction. The average initation time of oxidation for blackcurrant seed oils ranged from 30.56 to 46.47 minutes, and for rosehip seed oils, from 30.82 to 48.71 minutes. However, the stability of oils obtained from black currant seeds at a time of 5 minutes and amplitudes of 30% and 90%, as well as from rosehip seeds at a time of 10 minutes and an amplitude of 90%, did not differ from that of conventionally extracted oils. Optimization of ultrasound assisted extraction process made itpossible to obtain oils from fruit seeds with a prolongedoxidation induction time.