What are functional oils?

Functional oils are a class of oils with special physiological functions, which are a large class of fat-soluble substances that are needed for human nutrition and have a promoting effect on human health.
           
Functional oils and fats include oils and fats such as triglycerides, etc., as well as other nutrients such as VE, phospholipids and other lipids. At present, functional oils mainly include linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), as well as lecithin, cephalin and inositol phospholipids. In addition, some new structured lipids, fat-modified products and fat substitutes can also be included.
           
Polyunsaturated fatty acids (PUFA) are the main body of research and development of functional oils. They generally refer to fatty acids with two or more double bonds and a carbon chain length of 18 or more. According to their structure, they are divided into n-6 and n-3. The former mainly includes linoleic acid (18:2) ,γ-linolenic acid (18:3), arachidonic acid (20:4), etc. The latter mainly includes α-linolenic acid (18:3), eicosapentaenoic acid (EPA, 20:5), docosahexaenoic acid (DHA,22:6), etc.
           
Health Function of Functional Oil
           
The effect of polyunsaturated fatty acids on immune function
           
n-6 PUFAs have both inhibitory and stimulatory effects on immunity. Linoleic acid can be metabolized to arachidonic acid in the body, and can be further oxidized to eicosanoids, such as PGE2, leukotriene, thromboxane, etc., which play an important role in immune regulation. n-3 PUFA has an inhibitory effect on immunity, and foods rich in n-3 PUFA have anti-inflammatory and immunosuppressive effects.
           
Fish oil is rich in n-3 PUFAs, including EPA and DHA. Studies have shown that fish oil has a strong immunomodulatory effect, which depends on the dose, time and type of disease. Fish oil can reduce the response to endotoxin and cytokines, and has a certain auxiliary therapeutic effect on some bacterial diseases, chronic inflammation, and autoimmune diseases. Fish oil supplementation in healthy people can reduce the chemotaxis of monocytes and neutrophils and reduce the secretion of cytokines. In addition, fish oil has a role in rheumatoid arthritis, infectious enteritis and some asthma.
           
Polyunsaturated fatty acids and prevention of cardiovascular disease
           
Studies have shown that dietary intake of n -3 PUFA is negatively correlated with cardiovascular morbidity and mortality. Reasonable supplementation of fish oil in the daily diet can have a significant effect on the prevention and treatment of cardiovascular diseases.
           
n-3 The preventive and therapeutic effects of PUFA on cardiovascular diseases may be achieved through anti-thrombosis. EPA reduces platelet aggregation and blood viscosity by promoting the synthesis of certain twenty alkanoic acids. Animal model tests have shown that fish oil can prevent platelets from being deposited on the vascular wall and block the pathological process of atherosclerosis such as endothelial cell injury and wall thickening caused by lipid infiltration.
           
◆ Other effects of polyunsaturated fatty acids
           
EPA and DHA in the n-3 series of fatty acids are mainly derived from deep-sea fish oil, and α-linolenic acid is derived from vegetable oils. They can not only inhibit platelet aggregation, prevent thrombosis, reduce serum total cholesterol, low-density lipoprotein, very low-density lipoprotein and increase serum high-density lipoprotein, but also inhibit the production and metastasis of cancer. Most scholars believe that the n-3 series of fatty acids have an inhibitory effect on tumor cells, while other fatty acids have a promoting effect or no effect.
           
Common functional oils
           
◆ Wheat germ oil
           
Wheat germ oil contains 80% unsaturated fatty acids, in which the mass fraction of linoleic acid is more than 50%, oleic acid is 12% ~ 28%, in addition, its vitamin E content is higher. Wheat germ oil also contains twenty-three, twenty-five, twenty-six and twenty-eight alkanol, these higher alcohols, especially twenty-eight alkanol to reduce blood cholesterol, reduce muscle fatigue, increase the explosive force and endurance have a certain effect.
           
◆ Rice bran oil
           
Rice bran oil is extracted from rice bran. Rice bran oil contains 75% ~ 80% unsaturated fatty acids, of which oleic acid is 40% ~ 50%, linoleic acid is 29% ~ 42%, linolenic acid is 1%. Rice bran oil is also high in vitamin E and contains a certain amount of oryzanol.
           
◆ Corn germ oil
           
More than 80% of the fat in corn exists in corn germ. Corn germ oil extracted from corn germ is a multifunctional nutrition and health oil. It is rich in polyunsaturated fatty acids, vitamin E, β-carotene and other nutrients. It has special functions in reducing serum cholesterol, preventing and treating hypertension, heart disease, arteriosclerosis and diabetes.
           
◆ Safflower seed oil
           
Safflower seed oil is extracted from safflower seeds, and the mass fraction of linoleic acid is as high as 75% ~ 78%. In addition, it also contains oleic acid 10% ~ 15%,α-linolenic acid 2% ~ 3%, etc. Animal experiments have shown that safflower seed oil can not only significantly reduce serum cholesterol and triglyceride levels, but also has a significant effect on the prevention and treatment of atherosclerosis.
           
◆ Evening primrose oil
           
Evening primrose oil is extracted from evening primrose seeds and contains more than 90% unsaturated fatty acids, of which about 73% is linoleic acid and 5% ~ 15% is γ-linolenic acid. Functional foods containing γ-linolenic acid have become nutritional supplements for infants, the elderly and convalescent patients.
           
◆ Deep sea fish oil
           
Deep sea fish oil mainly contains DHA and EPA, because the two often exist at the same time, so the product is also a mixture of the two. Deep-sea fish oil is mainly found in the fat of fish swimming in the deep sea. For example, DHA in sardine fat can reach 20% and EPA can reach about 8%. The main function of deep-sea fish oil is to reduce blood lipids.
           
◆ Arachidonic acid
           
At present, arachidonic acid is mainly produced by biological fermentation, and the oil rich in arachidonic acid has obvious effect on enhancing memory and promoting brain tissue cell development.
           
◆ Phospholipids
           
It is mainly extracted from the by-products of refined vegetable oil or egg yolk. Phospholipids play a key role in maintaining the physiological activity of biological membranes and the normal metabolism of the body, such as regulating blood lipids, preventing and improving cardiovascular diseases, promoting nerve conduction, promoting fat metabolism, and preventing fatty liver.
           
◆ Structural lipids
           
Structured lipids have the physical properties of natural oils and have attracted much attention because of their special physiological functions and nutritional value to the human body. Structured lipids mainly combine short carbon chain fatty acids, medium carbon chain fatty acids and long carbon chain fatty acids with glycerol to form new lipids. This new lipid can maximize the physiological functions and nutritional value of various fatty acids.
           
Structured lipids are different from simple mixtures of LCT and MCT (carbon chain fatty acid triesters), but combine various fatty acids in balance to provide ideal, convenient and reasonable nutritional lipids.
           
Structured lipids can reduce the content of triglyceride and cholesterol in serum, prevent thrombosis, and improve immune function. In developed countries such as Europe, America and Japan, structured lipids have been industrially produced and entered the market. Our research in this field is still in its infancy.
           
◆ Other functional oils and fats
           
Functional oils also include linseed oil, sunflower seed oil, tea oil, olive oil, walnut oil, sea buckthorn oil, wolfberry seed oil, grape seed oil, kiwi seed oil, etc. These newly developed edible oils are gradually entering the market.
 
Application of Functional Oils and Fats in Baked Food
           
The baking industry is an important part of the food industry, and its products are directly oriented to consumers. According to the data released by the National Bureau of Statistics in recent years, China currently has nearly 2,000 baking food enterprises (with an annual output value of more than 5 million yuan), nearly 400000 employees, and an industrial output value of more than 50 billion yuan, which does not include large and small bakery houses and bakery houses all over the country. The actual number of employees in the baking industry may reach more than 1 million people, and the output value is about 80 billion yuan. The quality of baked food is closely related to the health of consumers.
           
Oil is one of the three basic raw materials used in the baking industry, the performance of oil determines the quality of baked goods to a certain extent, foreign countries are committed to the development of functional oils to produce high-quality baked goods, but China is still mainly using traditional plant, animal fat or margarine. With the improvement of living standards, the basic raw materials of baking food in China are developing in the direction of standardization and specialization. The baking food industry will also put forward higher requirements for oils and fats, and functional oils will play an increasingly important role in the development of baking food industry.
           
At present, the development direction of edible oil products is multi-variety, high quality, functionalization and specialization. There have been obvious breakthroughs in the variety of edible oils. For example, Japan's Nissin Oil Company has produced 400 kinds of oil products and 450 kinds of processed products, including various functional oils. These oils are developed according to the technical requirements of various types of food, and can be selected according to specific needs when used. Foods made by users using functional oils and fats significantly increase the nutritional and health functions of foods and improve the sensory properties of foods. Compared with foods made from traditional oils and fats, they are more popular with consumers.
           
Domestic edible oils and fats are mostly common shortening, frying oil, etc. A variety of foods can be used in the same type, and functional oils with health care functions are rarely used. It can be argued that the development and application of oils and fats for baking food in China is still at a primary level, which is also an important issue for domestic baking food enterprises to adjust their product structure. Some successful examples of the application of new functional oils in some foreign bakery enterprises may be a good reference.
           
Japan has developed powder EPA (eicosapentaenoic acid) oil with good oxidation stability. The product is obtained by mixing protein solution with EPA oil, homogenizing, emulsifying and spray drying with a high-pressure homogenizer. The product has extremely high thermal stability. It is heated at 180 ℃ for 40 min,POV (oil oxidation value) and fatty acid composition remain unchanged, and an aqueous solution with a mass fraction of 10% is heated at 90 ℃ for 1 h or 121 ℃ for 30 min,EPA content and POV remained unchanged; storage for 90 days, the fatty acid composition did not change. The new functional oil developed by coconut oil in the Philippines has three functions: fat substitute, flavor esterification and antibacterial. The coconut oil is hydrolyzed by lipase to produce low-calorie medium-chain triglycerides (MCT), which has a good effect in baked goods. Japan Kao Company has recently developed two functional oils for making bread and biscuits.
           
One is made from vegetable oil by lipase. It can be mixed with the emulsifier monoglyceride in the liquid crystal state to become a special emulsified oil suitable for bread production. The bread made with it is as soft as the bread just baked with margarine after being placed for 3 days. Another functional grease is synthetic long-chain alkyl grease, which has a high affinity with liquid grease. When it is mixed with liquid grease such as palm oil to make biscuits, problems such as oil discharge on the surface of biscuits due to large oiliness can be avoided.
           
Nowadays, all kinds of functional oil products are gradually becoming commodities to enter the food ingredients market. Domestic bakery enterprises should actively apply and improve the traditional technology, so that the quality and function of bakery products can be obviously improved, and good economic benefits can be achieved while meeting the market demand.