Seeds recovered from industry by-products of nine fruit species with a high potential utility as a source of unconventional oil for biodiesel and cosmetic and pharmaceutical sectors

Abstract

The composition of fatty acids and phytosterols of oils recovered from the seeds of nine industrial fruit by-products: watermelon (Citrullus lanatus), honeydew melon (Cucumis melo), sea buckthorn (Hippophae rhamnoides), red currant (Ribes rubrum), pomegranate (Punica granatum), Japanese quince (Chaenomeles japonica), grape (Vitis vinifera), gooseberry (Ribes uva-crispa) and apple (Malus domestica) were studied. The oil yield in the investigated fruit seeds ranged from 11.8% (sea buckthorn) to 28.5% (watermelon). The main phytosterol identified in all fruit seed oils was β-sitosterol with the concentration ranging between 0.5 and 3.1mg/g of oil, in watermelon and Japanese quince, respectively. The fatty acid composition was unique for each fruit seed oil. The majority of samples had high linoleic acid content (38.0–70.7%), whereas the pomegranate seed oil was extremely rich in punicic acid (86.2%). Japanese quince seed oil had the highest potential value for biodiesel production; while the unique profile of bioactive compounds recorded in pomegranate seed oil indicated great potential for utilization in cosmetic and/or pharmaceutical industries. The ΣPUFA/(ΣSFA+ΣMUFA) ratio of nine fruit seed oils highly correlated (r>0.9, p<0.0001) with all biodiesel properties, with the exception of the cold filter plugging point.