Macadamia oil extraction methods and uses for the defatted meal byproduct

•Macadamia nuts show high nutritional value.•Macadamia oil extraction by cold pressing presents low yield.•Lipid content of macadamia meal influences the water and oil holding capacity.•Fatty acid composition of macadamia oil has potential in the cosmetic industry.•Defatted macadamia meal shows potential as an ingredient in the food industry.

BackgroundThe trend towards the consumption of functional foods that aid in the maintenance of human health has increased in recent decades. In this way, macadamia nut contains bioactive compounds and high levels of monounsaturated fatty acids that are beneficial to health and can be minimally processed or industrialized for the production of oil and defatted flour.Scope and approachThe extraction of macadamia oil is commonly performed by cold pressing; however, the process presents low extraction yields, generating partially defatted meal as a byproduct, which can be subjected to further processing to increase the yield of oil extraction. Thus, studies about different methods of extraction and evaluation of the defatted material properties, such as color, water and oil holding capacity and solubility of the protein fraction were considered in this work.Key findings and conclusionsIt was found that the fatty acid composition of macadamia oil allows for its diverse use in many industries, i.e. cosmetics and pharmaceutical, while evaluation of the functional properties of the protein fraction of the defatted meal have shown that this byproduct can be used in food industry. Subsequent studies of the macadamia oil extraction process should enable the preservation of oil quality, in terms of fatty acid composition and bioactive compounds, and the functional properties of the defatted meal.