BRIEFING PAPER: Culinary oils and their health effects

Abstract

Summary Introduction Worldwide production, processing and consumption Production, storage and processing Culinary oils, nutrition and health Contribution of culinary oils to nutrient intakes in the UK diet The culinary oils Developments in culinary oils Culinary oils in a healthy, balanced diet Conclusions Acknowledgements References Summary Vegetable oils are mainly produced from oilseeds (e.g. rapeseed and sunflower seed) as well as from legumes (e.g. peanut and soybean), nuts (e.g. walnut and almond) and the flesh of some fruits (e.g. olives). Vegetable oils are pressed from the plants and are then processed and refined to produce high‐quality oils suitable for use as an ingredient in recipes, for frying, in salad dressings and in the production of margarines and spreads. There has been substantial growth in the oilseeds markets over the past 30 years. This was initially driven by health concerns but, more recently, has been because of the interest in biofuels and the changing market. In 2008, the four main types of vegetable oil that dominated the world market (in terms of the quantities produced) were palm oil, soybean oil, rapeseed oil and sunflower seed oil. In the UK, the only oilseed crops harvested are rapeseed, hempseed and linseed/flaxseed. However, there are substantial imports of groundnuts, soybeans, sunflowers and palm kernels that are processed in the UK resulting in the production of a variety of different oils in the UK. Vegetable oils mainly comprise triacylglycerides. The main nutrient they provide is fat. The only other nutrient that is present in appreciable amounts is vitamin E (tocopherols and tocotrienols). Vegetable oils are also the main source of natural plant sterols in the diet and contain minor components, such as squalene and sphingolipids, all of which may provide a range of health benefits. The fatty acid composition of plant oils varies, and all plant oils are composed of a mixture of different fatty acids, in different proportions. Most culinary oils tend to be high in either monounsaturates or polyunsaturates, with the exception of palm kernel and coconut oils which are high in saturates. Categorising fats as ‘saturated fats’, ‘monounsaturated fats’ or ‘polyunsaturated fats’ (based on the predominant fatty acid) may be helpful for consumer understanding. However, this is an oversimplification of the actual situation. The constituent fatty acids of each culinary oil are primarily responsible for the functionality of the oil, along with the minor components. The properties of the oil can be modified through technical processes including hydrogenation, fractionation and interesterification. The processes used to modify the properties of oils have become a widely debated topic. Hydrogenation was a commonly used process to increase hardness and to stabilise fats without having to increase saturates to any great extent. However, as partial hydrogenation results in the formation of trans fatty acids, its use in the UK for consumer products has now virtually ceased. Some food man...

Chemical composition of oils from wild almond (<i>Prunus scoparia</i>) and wild pistachio (<i>Pistacia atlantica</i>)

“…The minor components include mono and diglycerides, free fatty acids, tocopherols, sterols, carotenoids and polyphenols. Tocopherols act as antioxidants and are required to protect cells against oxidative damage by free radicals (Foster et al, 2009). Tocopherols and carotenoids improve oil stability and thus oils naturally rich in these constituents are preferred (Warner and Frankel, 1987;Frankel, 1991).…”

Evaluation of antidiabetic properties of cactus pear seed oil in rats

“…Therefore, functional foods, such as plants extracts, administered before meals can have a beneficial effect on hyperglycemia. Vegetable oils can improve cellular glucose tolerance and thus decrease blood glucose level (Foster et al, 2009 (Griffith, 2004) and is popular throughout the Mediterranean area and Morocco. The fresh fruits are widely consumed, and parts are used as functional foods, therapeutics, and animal food (Feugang et al, 2006).…”

Effects of Water Stress on Germination and Growth of Linseed Seedlings (Linum usitatissimum L), Photosynthetic Efficiency and Accumulation of Metabolites

“…The oil of linseed is an excellent nutritional supplement being rich in α-linolenic acid and omega-3 fatty acid. The oil is also used in the production of industrial raw materials (Vaisey-Genser & Morris, 2003;Foster et al, 2009;McKenzie & Deyholos, 2011). In the textile industry, the fibers of linseed have been largely replaced by cotton or by synthetic fibers but they are still used in the high-quality linen materials and are also now being incorporated in the polymeric matrix of biocomposites to improve their mechanical properties (Chemikosova et al, 2006;Bodros et al, 2007;Huis et al, 2010).…”