Edible oil is an indispensable part of people’s daily diet. It is one of the three nutrients that supply human heat energy. It is also an important source of essential fatty acids, fat soluble vitamins and phospholipids required by the human body.When we cook food, oil is absolutely necessary.
Oil can be divided into two species of animal and plant. Animal fat includes lard, butter, lamb oil and cream.Vegetable fats include peanut oil, rapeseed oil, sesame oil, soybean oil ,cottonseed oil and so on.The nutritional value of oils varies according to their absorptivity.The absorption rate of the general solution below 37℃ is the highest, which can reach 97% ~ 98%.The absorptivity of 37℃ ~ 50 ℃C is 90%,It is difficult to absorb more than 60℃.The content of saturated fatty acid in animal fat is high, its solubility is high, its solid state is normal at room temperature, and its digestibility and absorption rate is low.Vegetable oil has high content of unsaturated fatty acids, low melting point, liquid at room temperature, and high digestibility and absorption rate than animal oil.
In animal fat, it contains mainly saturated fatty acids, and the content of cholesterol is also high.If you eat too much in your diet, it will increase the cholesterol content in the blood, which is significantly related to the incidence of hyperlipidemia, coronary heart disease and mortality.Therefore, patients with hyperlipidemia and hypertension should eat less animal fat and should usually eat lean pork and lean beef.But if the fat meat are cooked properly, can also be eaten in moderation. After a long time of simmering, boiling and cooking, the content of saturated fatty acids and cholesterol will drop a lot.
Animal fat can increase its taste when cooking dishes.For example, the pig is white and has meat flavor. It can make some clear and white dishes, such as Hibiscus dishes. It is not only bright and white, but also soft and tender.Some vegetables, such as radish, have low fat content. If they are cooked with lard, they will be lubricated and fragrant, which will increase their appetite.
No matter vegetarian or meaty, both of which are not meet the requirements of nutrition.A reasonable balanced diet is an important condition to meet the normal physiological needs of the human body and ensure good health.Therefore, in daily life, diversification of diet is advocated, and oils and fats are also the same.
Vegetable fats should not be chosen singly, but animal fat (including animal food) can be added to the right amount.The ratio of vegetable oil to animal oil is 1:0.7.
There are many kinds of vegetable oils, such as soybean oil, peanut oil, corn oil, rapeseed oil, sunflower oil and so on.These oils contain lots of polyunsaturated fatty acids and vitamin E. The highest content of soybean oil is potassium, sodium, calcium, phosphorus, iron, zinc, manganese, selenium and other inorganic salts and trace elements.At present, the senior cooking oil sold on the market is made from the above oils and fats through many times refining process.Refining is deacidification, degumming, deodorization, decolorization, dewaxing and deperoxide, that is to say, which means remove all harmful substances in crude oil.According to international standards, peroxide content is not more than 0.15%, and five of the oil above is an international premium cooking oil.
In recent years, the people’s living standard has been greatly improved, from the food and clothing type to the well-off type gradually, more and more animal food intake in daily diet, the variety of subfood on the table of each family is becoming more and more rich, so the supply of fat is greatly increased.A large number of epidemiological data show that excessive fat content in diet has a certain relationship with the incidence of cancer.The daily fat supply standard should be 20 to 25% of the total heat energy.Excessive consumption of vegetable oil is not conductive to human health.For example, the higher content of erucic acid in rapeseed oil has the effect of inducing myocardial lesions in the human body, and is not suitable for patients with heart disease.A small amount of arachic acid in peanut oil can cause coronary atherosclerotic lesions.The dangerous components in vegetable oils, such as peroxy fat, also cause liver cirrhosis, gastric ulcers, and easily cause geriatric diseases. So the intake of vegetable oil should not be too much.