Oils and fats are all higher fatty acid glycerides, collectively referred to as oils and fats. Generally, liquid at room temperature is called oil, and solid at room temperature is called fat. It is a complex mixture formed by sugar conversion during the maturity of oilseed, and it is the main chemical component in oilseed. The main components of oils and fats are glycerides of various higher fatty acids. [Edit this paragraph] Oils are widely distributed. Seeds of various plants, tissues and organs of animals contain a certain amount of oil, especially seeds of oil crops and subcutaneous adipose tissue of animals, which are rich in oil. Fat in human body accounts for about 10%~20% of body weight. [Edit this paragraph] When the carbon chain of chemical oil contains carbon-carbon double bonds (namely unsaturated fatty acid glycerides), it is mainly vegetable oil with low boiling point; When the carbon chain in oil is a single carbon-carbon bond (saturated fatty acid glyceride), it is mainly animal fat with high boiling point.

Among them, oil can undergo addition reaction (such as hydrogenation) and oil can be hydrolyzed.

C 17H35COOCH2

c 17h 35 cooch+3 NaOH→3c 17h 32 coona+ch 2 ohchohch 2 oh

C 17H35COOCH2

C 17H35COOCH2 acid

c 17h 35 cooch+3H2O→3c 17h 32 cooh+ch 2 ohchohch 2 oh

C 17H35COOCH2

Oil is an important part of food composition, and it is also the nutrient with the highest energy production under the same quality. When 1g oil is completely oxidized (producing carbon dioxide and water), it releases about 39kJ of heat, which is about twice that of sugar or protein. Adults need to consume 50~60g of fat every day, which can provide 20%~25% of daily calories.

The chemical changes of fat in human body are mainly catalyzed by lipase, which hydrolyzes into glycerol and higher fatty acids, and then oxidizes and decomposes to release energy. Oil can also keep body temperature and protect internal organs. [Edit this paragraph] function

Fatty acids in bound or free state are saturated, such as lauric acid, palmitic acid and stearic acid.

Unsaturated such as oleic acid, linoleic acid, linolenic acid, etc. Oil is insoluble in water, but soluble in organic solvents such as hydrocarbons, alcohols, ketones, ethers and esters. At higher temperature, in the presence of catalyst or lipolytic enzyme, fatty acids and glycerol are hydrolyzed. Saponified with hydroxides of calcium, potassium and sodium to form metal soap and glycerol. It can react with many other chemical reactions such as halogenation, sulfation, sulfonation, oxidation, hydrogenation, deoxidation, isomerization, polymerization, pyrolysis and so on. Mainly used in food, but also widely used in making soap, fatty acid, glycerin, paint, ink, emulsifier, lubricant and so on. [Edit this paragraph] There are four methods: squeezing, solvent extraction, water substitution and boiling. The obtained oil can be dephosphorized, dried, deacidified, deodorized and decolorized according to different needs.

The adipose tissue of animals and the kernel of oil plants are the main sources of oil.

What is solid or semi-solid at room temperature is called fat, and what is liquid is called oil. Fat contains more glycerides of higher saturated fatty acids, oil contains more glycerides of higher unsaturated fatty acids, and natural oils are mostly mixed glycerides (that is, r, R' and r "are different or not exactly the same). All kinds of oils and fats are mixtures of higher fatty acid glycerides. The average molecular weight of oil can be reflected by its saponification value (65438+mg KOH is needed for saponification of 0g oil). The smaller the saponification value, the larger the average molecular weight of oil. The unsaturation of oils and fats is usually expressed by iodine value (100g oils and fats need grams of I2 when they react with iodine). The greater the iodine value, the greater the degree of unsaturation of oil. The content of free fatty acids in oils and fats is usually expressed by acid value (mg KOH required to neutralize 1g oils and fats). The acid value of fresh oil is extremely low, and the acid value of improperly preserved oil will increase due to oxidation and other reasons. Some oils can form a hard and elastic film in air. Oils with this property are called drying oil (iodine value is greater than 130), such as tung oil and linseed oil. Wax, like oil, is an ester widely existing in nature. The main components of wax are usually esters of higher saturated fatty acids and higher monohydric alcohols with even carbon atoms. For example, the main components of ash are wax esters of palmitic acid, beeswax esters of palmitic acid and cetylpalmitate. Because of habit, some waxes are not esters. For example, paraffin wax is a higher alkane, while polyethylene glycol is a synthetic wax.

Because fatty acid is an acid, it can be washed off with alkaline soap.

Oil is an important energy supply substance for human body, which can be stored in human body and become a standby energy substance to maintain life activities. [Edit this paragraph] Oils with more "unsaturated fatty acids" are recommended: including soybean oil, sunflower oil, corn oil, safflower oil and linseed oil. Suitable for all kinds of vegetarians, especially those who eat more animal food and less plant food.

Oils with more monounsaturated fatty acids, including olive oil and tea seed oil, are suitable for all kinds of vegetarians, especially middle-aged and elderly people and patients with hyperlipidemia, because of their good blood lipid lowering effect.

Oils with balanced unsaturated fatty acids: including peanut oil and sesame oil; Suitable for all kinds of people.

Oils with more "saturated fatty acids" include palm oil, lard, butter, sheep oil, butter, vegetable butter and coconut oil. Suitable for vegetarians or people who seldom eat animal food. [Edit this paragraph] Oil consulting, recruitment and job hunting The oil industry is mainly divided into industrial oil and edible oil. Edible oil is divided into vegetable oil and animal oil. As the dominant vegetable edible oil in the current market, its main raw material is soybeans from abroad, so general oil enterprises are distributed in coastal areas, such as Shandong, Liaoning, Guangdong, Jiangsu, Zhejiang and other places. In addition, soybean meal and other by-products produced in the process of oil extraction have formed a feed industry chain close to the oil industry, supporting the development of aquaculture and other industries.

Job requirements in the petroleum industry mainly involve workshop operations, inspection and testing, warehousing and logistics, etc. And it has also driven a large number of secondary industries such as mechanized installation and maintenance and feed processing around. Therefore, from large-scale engineering and technical personnel to project management, these are the talents needed by the oil industry.

At present, the main information consulting media and job-seeking media in the domestic oil industry are China Petroleum, China Petroleum Network, China Petroleum Network and Petroleum Talent Network. [Edit this paragraph] The future direction of petroleum industry is completely controlled by foreign countries, because domestic petroleum processing raw materials have long relied on foreign imports. As a big agricultural country, China and China have begun to vigorously protect the oil processing industry. In the future, China will get rid of the present situation of "keeping oil on one side", and let domestic native soybeans become the main ingredient, so that people can get rid of the situation of eating foreign oil.