3 - Tree Nut Oils

Abstract

The major tree nuts include almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, pecans, pine nuts, pistachio nuts, and walnuts. Tree nuts belong to several plant families; however, their common features are that they are rich in oil and the nuts are larger in size than the seeds of oilseed species. Tree nut oils are appreciated in food applications because of their flavors and are generally more expensive than other gourmet oils. Before oil extraction, the nuts first need to be removed from the shell and then from the husk. The nut oils differ in their oxidative stabilities, which dictates the processing and storage conditions that are applied to each nut. Nut oils are also extracted from the nuts by Supercritical Fluid Extraction (SFE) using compressed carbon dioxide in wide temperature and pressure ranges. Nut-kernel oils are used as: salad oils, in cooking and other food applications, in massages and as lubricants, as emollients in pharmaceuticals, and in cosmetics, soaps, shampoos and hair conditioning/repair products, skin lotions, and other cosmetic products. Some tree nut oils, such as hazelnut oil, may serve as cooking oils in specialty dishes because of their unique flavors.