The oil press refers to a machine that squeezes grease out of the oil by increasing the temperature and activating the oil molecules with the help of external mechanical forces.
Oil presses can be divided into household oil presses, hydraulic oil presses, screw oil presses, new hydraulic oil presses, high-efficiency oil presses, and fully automatic oil presses.
The raw materials of the oil press, that is, the oil crops are divided into plant raw materials and animal raw materials according to their types. In the general production process, we mainly use plant raw materials. The plant raw materials are divided into legumes, seeds and hempaceae. The following is a brief description of my country’s oil crops:
Peanuts: Peanuts are bean crops. In history, they were called longevity fruit, groundnut, pine pine, longevity fruit, fig, etc. Peanuts nourish the stomach and prolong life. It is also called “longevity fruit” in the folks. It is also known as “plant meat” and “vegetarian meat” like soybeans. The nutritional value of peanuts is higher than that of grains, comparable to some animal foods such as eggs, milk, meat, etc. It contains a large amount of protein, especially high content of unsaturated fatty acids, and is very suitable for manufacturing various nutritious foods. Peanut is an annual herb. It is also an important oil crop with many varieties. The general chemical composition of peanuts is: moisture 5.33%～9.16%, oil content 44.27%～53.86%, carbohydrate 9.89%～23.62%, protein 23.96%～33.94%, phospholipid 0.5%～ 1.5%, crude fiber 2.67%～5.26%, ash content 1.75%～2.58%. It can be seen that peanuts contain a lot of oil (fat) and protein, which is a good oil crop. Among them, protein 23.96%～33.94% is better than lean pork, The protein of beef and mutton is 1.5-2.5 times higher than that of rice and flour; 5-13 times higher than that of rice and flour, and the digestibility coefficient of protein is very high. It is rich in amino acids needed by the human body; vitamin B1, B6, vitamin D, E, calcium and phosphorus, etc. Minerals. my country’s peanut planting area ranks second in the world. The peanut series products have been welcomed by consumers for a long time. But the catch is that “peanuts have a high fat content, and the taste is too greasy when eaten, which leads to a series of fatty diseases in the human body.
Soybean: It belongs to the legume family and is an annual herb. Its seeds are also called soybeans. It is the most important legume in the world. Soybean originated in China, and most Chinese scholars believe that the origin is the Yunnan-Guizhou Plateau. There are also many botanists who believe that it is derived from Ussuri soybeans, which are native to China. The cultivated soybeans now planted are made from wild soybeans through long-term directional selection, improvement and domestication. Soybeans are rich in high-quality protein, unsaturated fatty acids, calcium and B vitamins, which are important sources of high-quality protein in the diets of Chinese residents. Soy protein content is about 35%-40%. Except for methionine, the composition and proportion of other essential amino acids are similar to animal protein, and it is rich in lysine, which is lacking in cereal protein. It is a natural and ideal food complementary to cereal protein. The fat content of soybeans is about 15%-20%, of which unsaturated fatty acids account for 85%, linoleic acid is as high as 50%, and the digestibility is high, and it also contains more phospholipids. The carbohydrate content in soybeans is about 25%-30%, and half of it is dietary fiber. Among them, raffinose and stachyose are fermented to produce gas under the action of intestinal bacteria, which can cause abdominal distension. Soybeans are rich in phosphorus, iron, and calcium. Each 100g of soybeans contains 571mg of phosphorus, 11mg of iron, and 367mg of calcium, which are significantly more than cereals. Due to the relatively low oil yield of soybeans, the oil is generally used for extraction. For oil, the general oil production enterprises in my country use foreign genetically modified soybeans as raw materials, because genetically modified soybeans contain as much as 25%-35% oil.
Sesame: (scientific name: Sesamum indicum) Sesamaceae, is the seed of flax. Although its close relatives have appeared in Africa, the natural origin of the breed is still unknown. It is found all over the tropical regions of the world. Sesame is one of the four major edible oil crops in my country and one of the main oil crops in China. Sesame products have higher application value. The oil content of its seeds is as high as 61%. Since ancient times, there have been many famous special foods and delicacies made with sesame and sesame oil in our country, and they have been famous all over the world. Sesame flowers are solitary, or two or three clusters grow in leaf axils. Cylindrical, lip-shaped, made of sesame seeds (14 photos) pale red, purple, and white. The number of edges of the long cylindrical capsule varies from 4.6.8 due to different varieties. The seeds are oblate, white, yellow, reddish brown or black. The white seeds have a higher oil content. The black seeds are used as medicine and have a sweet taste. They have the functions of nourishing liver and kidney, moisturizing dryness and laxative. Sesame oil contains a lot of essential fatty acids, and the content of linoleic acid is as high as 43.7%, which is higher than rape oil and peanut oil. Aromatic oil can be extracted from the stems, leaves and flowers of sesame. The oil produced by pressing sesame seeds is commonly called sesame oil. It has a mellow and rich smell and is an important seasoning and cooking oil.
Rapeseed, also known as oil cabbage, bitter cabbage, is the tender stems and leaves of the cruciferous rapeseed. It is native to my country and has a dark green color. It is a variety of cabbage in the cruciferous family. The north and the south are widely cultivated and are available in all seasons. Rape contains a variety of nutrients and is rich in vitamin C. The northern small rapeseed is native to western China, and is distributed in northwest China, northern China, Inner Mongolia, and provinces (regions) in the Yangtze River basin. It is also widely distributed all over the world. Rapeseed oil contains a variety of vitamins, such as vitamin A, vitamin D and vitamin E, which is an important source of fat-soluble vitamins in the human body. Rapeseed oil is rich in vitamin E, up to 60 mg/100 g oil, especially the vitamin E content is as high as 13 mg/100 g oil, which is 2.6 times that of soybean oil, and it does not decrease much after long-term storage and heating. It can be used as The source of vitamin E in food. Rapeseed oil contains 45%, and the linoleic acid content has risen to about 20%, so that the fatty acid composition of canola oil is similar to tea oil and peanut oil. The successful cultivation of low-linolenic rapeseed reduced the content of linolenic acid, which is easily oxidized and deteriorated and hindered the metabolism of linoleic acid, to about 3%. In this way, the disadvantages of high erucic acid and linolenic acid content in the original conventional rapeseed oil were completely overcome. More than 90% of the fatty acids in rape oil are essential fatty acids-linoleic acid and oleic acid with higher nutritional value.
Flaxseed: Flaxseed is an oil crop. Flax oil contains a lot of unsaturated fatty acids, so it is used to prevent hyperlipidemia and atherosclerosis. The surface of flax seeds is mostly reddish-brown or gray-brown, brown, a few golden yellow and white, smooth and shiny surface, 30%-45% oil content, linseed oil is rich in linoleic acid, linoleic acid and other unsaturated fatty acids, especially It is rich in a-linolenic acid and r-linolenic acid, which are necessary for the human body, of which a-linolenic acid accounts for 57% of the fatty acids of linseed oil, which is 2 times higher than fish oil. It can reduce human blood pressure, serum cholesterol, blood viscosity, and has therapeutic effects on cancer, cardiovascular disease, visceral disease, kidney disease, skin disease, arthritis, lung disease, immune system disease, etc. More than 30 countries such as the United Kingdom and France have approved the use of linseed oil as a nutritional additive or functional food. Flax oil is the oil extracted from the seeds of the flax family plant flax. Linseed contains 30%～48% oil. The oil obtained by pressing at room temperature is a yellow liquid with a peculiar smell. The texture gradually thickens in the air and the color gradually darkens. The main components of the oil include linolenic acid and linoleic acid. , Oleic acid, palmitic acid, stearic acid and other glyceric acids. In addition, it also contains organic compounds such as eicosanyl ferulic acid, a variety of steroids, triterpenes, and cyanogenic glycosides. Flax oil is mainly used as an industrial raw material for coatings, inks, linoleum, and rubber. A small number of areas are traditionally used as edible oil. Has a certain medicinal value.
(1) Peanut is a kind of crop with high oil content. Its internal oil exists in the cell in spherical or granular form and is surrounded by a layer of closed film. In the process of being squeezed by the outside, this layer of film and cell wall When they burst together, the peanut oil will flow out from the cracks. During the extrusion process, the oil in the peanuts is partially squeezed out, and the peanuts become brittle and hard, losing their original elasticity; while the peanut red coat contains more fiber, which is under pressure. Later, it is separated from the surface of the peanut, so that the peanut red coat is easy to fall off; in the extrusion process, the peanut is subjected to pressure rather than shearing force, so there is no phenomenon of broken kernels, and it is easy to restore the original shape;
(2) Different pressures are applied according to the requirements of fat content. Different defatted peanuts can be obtained.
Process requirements: peanut degreasing rate is more than 50%; peanuts are intact without broken pieces, there is no adhesion between peanuts, and the red coat of peanuts is easy to fall off. The most important factor influencing the degreasing effect is moisture, and the secondary factor is time. The optimal conditions for achieving the degreasing effect are 4.52%-7.26%. (Excessive moisture will affect the oil yield, and excessive moisture will easily cause the peanut breakage rate to be too high.)
The production process of peanut crude oil
Peanut kernels-temperature controlled drying-raw material wrapping-pressure-defatted peanut kernels