Macadamia oil

In addition to the health benefits of phenohc compounds in oils, the antioxidants contribute to the oxidative stability of the nuts and oils and extend their shelf life. When macadamia oil is obtained from the crushed nuts and shehs by cold processing, some of the antioxidants leech from the shehs into the oil and increase the antioxidant content. Unfortunately, during the refining of macadamia nut oil products, many of the antioxidants are removed [20]. Phenohc compounds also have organoleptic properties, which color and flavor the oils [20,21]. 

Intervention trials have demonstrated that consumption of a small handful of macadamia nuts lower plasma cholesterol (Table 15.2). Macadamia nuts are an excellent source of MUFA (such as 18 lco9 and 16 1) that are known for their beneficial effects on circulating lipid levels. Four human clinical trials have evaluated the lipid lowering potential of macadamia nuts [22-25] another one involved macadamia oil [26]. 

Concentrates (70-75%) can be obtained from these relatively cheap sources by hydrophilisation. Richer sources of oleic acid include rapeseed oil (56%), macadamia oil (56% and a further 22 % of 16 1), almond oil (61%), high-oleic safflower oil (74%), olive oil (18%), high-oleic sunflower oil (Sunola, 82% and NuSun, 65 %) and Euphorbia lathyris seed oil (84%). 

Studies evaluated the oxidative stability of macadamia oil, obtained using different types of macadamia nuts [28]. The OSI of natural raw salted nuts stored for 4 months was 70 h, and the OSI of natural raw imsalted nuts was 88.6 h. The almond oil is better protected at low temperatures however, even under frozen storage, there is a reduction in the stability of the oil. The OSI of fried imsalted nuts was 40.3 h as a consequence... 

Table 7. Carbohydrate, Nitrogen, and Oil Levels in Macadamia Embryos as a Function of Age ...

Commercially important nuts ia world trade iaclude almond, Bra2il nut, cashew, chestnut, coconut (copra), filbert, macadamia, palm nut, peanut, pecan, pignoHa, pistachio, and Knglish walnut. Coconut, palm nut, peanut, as well as babassu, oiticia, and tung, are important sources of oil for soap, paint, varnish, as well as many other domestic and iadustrial uses. 

Fard, A. M., Turner, A. G., and Willett, G. D. (2003). High-resolution electrospray-ionization Fourier-transform ion cyclotron resonance and gas chromatography-mass spectrometry of Macadamia nut oil. Aust. J. Chem. 56,499-508. 

There are a number of minor oils, all of high value, most of which are marketed mainly either for medical purposes or for their flavour. Olive, evening primrose, borage, fish oils and cocoa butter are described elsewhere. Others include hazelnut, walnut, macadamia, almond, apricot, pumpkin, poppy-seed and rice bran oils. The process of testing for authenticity of these oils should be approached in the same way as for the bulk oils above, i.e. fatty acid profile, sterols, tocopherols and triglyceride composition. However, there is little generally available published material on the ranges of values to be expected... 

Macadamia (Macadonia integrifolia, M. tetraphylla). The nuts are used as a snack food. They are rich in oil (60-70%), which is used in cosmetics and is available as a gourmet oil. It is characterized by its high level of monoene acids [total 80%, 16 1 16-23%, 18 1 55-65%, 20 1 l-3%] and is a convenient source of the... 

Every oil has a different smoke point—the temperature after which it is no longer healthy and begins to smoke. Some oils, such as flaxseed oil, have a very low smoke point and, as a result, should never be heated. Olive oil smokes at just under 325°F, while macadamia nut oil reaches its smoke point at around 4io°F, allowing you to cook with it at higher temperatures without destroying the health benefits of the oil (unless the oil has been overheated during manufacturing). When oils become rancid or overheated, the beneficial fatty acids break down into other compounds such as hydrocarbons, ketones, and aldehydes, all of which can raise the acidity of our bodies. 

Seed similar to macadamia nut, cultivated mostly for its high oil content... 

Tree nuts are appreciated worldwide for their desirable flavor attributes and are used extensively in confectionary, bakery, culinary, and other food product apphcations. Consumption of tree nuts has grown in recent years due to reports on the health benefits of a diet rich in nuts and nut oils [1,2]. The world s most popular tree nut is the almond followed by the walnut and the hazelnut (filbert). Other economically important tree nuts include pecan, Brazil nut, cashew, chesttiut, pistachio, macadamia, and pine nut. Despite their economic importance and growing popularity, httle information is available regarding the characteristic flavor and aroma constituents of most tree nuts. In fact, there has been little addition to the published literature on the subject since Maga s 1991 overview on the volatiles in nuts [3]. Hazelnut is an exception and extensive studies have been conducted to identify the volatile components of both the raw and roasted forms of this nut. This chapter presents an overview of the literature on the flavor and volatile compounds in tree nuts and discusses their possible origins. 

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