I. Key indicators
1, peroxide value.
The increase of peroxide value in edible vegetable oil shows that the increase of oxidation degree of vegetable oil will lead to inferior oxidation of oil, produce a large number of low molecular weight aldehydes and ketones harmful to human body, and reduce the nutritional value of vegetable oil. The Hygienic Standard for Edible Vegetable Oils stipulates that the peroxide value should be less than 0.25g/ 100g.
2. Acid value.
Acid value is an important hygienic index of edible vegetable oil. The increase of acid value in edible vegetable oil will lead to oil fission, reduce nutritional value and affect the normal digestive function of human body. Seriously inferior vegetable oil will produce substances harmful to human body. The Hygienic Standard for Edible Vegetable Oil stipulates that the acid value should be less than 3 mg/g. ..
3. Leaching grease solvent residue.
Edible vegetable oil produced by leaching process contains a small amount of leaching oil solvent, mainly hexaalkane, some of which (such as benzene) can promote leukemia. Solvent residue in extracted oil is an important hygienic index of edible vegetable oil. The Hygienic Standard for Edible Vegetable Oils stipulates that it should be less than 50mg/kg, and primary and secondary soybean oil should not be detected.
4. Heating test.
Heating test is a simple method to identify the refining degree of edible vegetable oil. Unqualified items indicate that the vegetable oil may be crude oil (crude oil), or the degree of refining may not be high, and the vegetable oil that does not meet the hygienic standard is inedible and cannot be put on the market.
Second, nutritional ingredients, edible efficacy and taboos
1, sesame oil
Sesame oil is rich in protein, unsaturated fatty acids, and some essential trace elements such as lecithin, linolenic acid and iron ore. Regular consumption has the effects of moistening stomach, nourishing yin, tonifying deficiency, helping digestion, improving eyesight, protecting liver, eliminating diseases and prolonging life, and has a special effect on constipation, hypertension and high cholesterol in the elderly, which is one of the reasons why Bama centenarians can live a long and healthy life after long-term consumption. Locals call it "Longevity Hemp" or "Longevity Oil".
2. Soybean oil
Soybean oil is obtained by solvent leaching of soybean seeds, which is the highest yield oil in the world. Crude unrefined soybean oil is not suitable for direct consumption, and refined soybean oil is the most common one at present. Its main fatty acids are linoleic acid, oleic acid, palmitic acid and linolenic acid.
? The main components of soybean oil are palmitic acid 7% ~ 10%, stearic acid 2% ~ 5%, arachidic acid 1% ~ 3%, oleic acid 22% ~ 30%, linoleic acid 50% ~ 60%, linolenic acid 5% ~ 9%, and a lot of vitamin e.
? nutritive value
1), soybean oil is rich in linoleic acid, which has obvious effect on reducing serum cholesterol content and preventing cardiovascular diseases;
2) In addition, the digestibility of soybean oil is as high as 98%, which is an excellent edible oil with high nutritional value.
? Health reminder
1), cooking with soybean oil is not heart-protecting, and it is more suitable for stewing;
2) If cooking with soybean oil, try not to burn it to 10, and do not smoke; Please note that any soybean oil that is not marked with "no genetically modified ingredients" is a genetically modified product.
3. Rapeseed oil
Rapeseed oil is taken from rapeseed, and its fatty acid composition is greatly influenced by climate and variety. The erucic acid content of traditional rapeseed oil is high, generally 20%-60%, in addition to glucosinolates. It has caused great controversy in the field of nutrition. It was found that young rats were fed with rapeseed oil (containing 45% erucic acid) which accounted for 5% of dietary energy, and fat deposition and fibrous tissue appeared in their myocardium. At present, rapeseed varieties without erucic acid or with low erucic acid have been cultivated. In terms of nutritional value, the digestibility of rapeseed oil can be as high as 99%, which is beneficial to gallbladder function. When the liver is in pathological state, the human body can also metabolize rapeseed ketone normally. Rapeseed oil lacks essential fatty acids such as linoleic acid, and its fatty acid composition is unbalanced, and its nutritional value is lower than that of ordinary vegetable oil. In addition, rapeseed oil contains a lot of erucic acid, glucosinolates and other substances, which are generally considered to be unfavorable to human growth and development. If it can be eaten with high-quality edible oil rich in linoleic acid, its nutritional value will be improved
major constituent
Rapeseed oil contains 0.4- 1.0% arachidic acid, 0.4-19% oleic acid, 0.2-24% linoleic acid, 3 1-55% erucic acid and 0/-linolenic acid.
? Health care efficacy
1), clearing liver and benefiting gallbladder. People with hepatobiliary problems, such as fatty liver, hepatitis, gallstones or cholecystitis, must choose rapeseed oil when cooking.
2) Reduce blood fat and lose weight. Rape has a strong role in promoting fat decomposition. People with hyperlipidemia and obesity can lose weight by eating rapeseed oil. Moreover, rapeseed oil is the most digestible oil, and its digestibility in human body can reach 99%. People with hepatitis and cholecystitis can't eat more other oils, and it's no problem to eat rapeseed oil.
? food therapy
1), rapeseed oil tastes sweet, pungent and warm; It can moisten dryness, kill insects, disperse fire pills, reduce swelling and detoxify, and it is clinically used for ascaris lumbricoides and food-borne intestinal obstruction with good effect.
2), rapeseed oil has anti-inflammatory effect: raw rapeseed oil has a certain effect on burns, because it can not only enter the blood, but also cool the blood and detoxify, can enter the lung meridian, and has the effect of promoting skin growth. Therefore, the ancients used it for external application to treat rubella, eczema and various skin itching.
3) Rapeseed oil can also improve eyesight: regular eating can prevent senile eye diseases. Rapeseed oil can also help eyes resist the stimulation of strong light, which is very helpful to prevent amblyopia in children.
? nutritive value
1), the absorption rate of rapeseed oil is very high, up to 99%. Therefore, it contains unsaturated fatty acids such as linoleic acid and vitamin E, which can be well absorbed by human body, and has certain effects of softening blood vessels and delaying aging.
2) Because the raw material of oil pressing is plant seeds, it generally contains some seed phospholipids, which is very important for the development of blood vessels, nerves and brain;
3) Rapeseed oil contains little or no cholesterol, and people who control cholesterol intake can safely eat it;
4) Rapeseed oil is an oil with a particularly high erucic acid content. Whether it will cause myocardial fat deposition and damage to the heart is still controversial, so patients with coronary heart disease and hypertension should pay attention to eating less.
Health reminder
It is harmless for ordinary people to eat rapeseed oil for a long time, but because rapeseed oil tastes sweet, pungent and warm, patients with coronary heart disease and hypertension should pay attention to eating less. Moreover, oil has a certain shelf life. Oil that has been left for too long is not edible, and oil that has been heated at high temperature should be avoided from being reused.
? 4.peanut oil
Peanut oil has a unique peanut smell and flavor, generally contains less non-glyceride components, and is rich in unsaturated fatty acids, linoleic acid, stearic acid and so on. Light in color and high in quality, it can be directly used to make shortening, and it is also a good frying oil, which is widely eaten in China.
major constituent
Peanut oil contains more than 80% unsaturated fatty acids (including oleic acid 4 1.2% and linoleic acid 37.6%). In addition, it also contains 19.9% saturated fatty acids such as palmitic acid, stearic acid and arachidic acid.
? nutritive value
From the above contents, the fatty acid composition of peanut oil is good, which is easily digested and absorbed by human body, and the cephalin, lecithin and choline contained in peanut oil can also effectively improve memory, which is beneficial to the baby's intellectual development.
? Health reminder
1), peanuts are easy to pollute aflatoxin, so you must choose high-quality peanut oil (preferably pressed oil);
2) Peanut oil has a particularly good flavor and good heat resistance. More suitable for general cooking, not for frying food.
5. Cottonseed oil
Cottonseed oil is a by-product of lint processing, of which only refined cottonseed oil can be eaten directly, and other cottonseed oils are not suitable for eating. The oil content of the whole seed is about 17%, and the oil content of the kernel is about 40%. The main fatty acids of cottonseed oil are palmitic acid, oleic acid and linoleic acid.
6. Corn oil
Corn oil is also called corn germ oil and corn oil. Corn germ accounts for 7%- 14% of the whole corn grain, and the germ contains 36%-47% oil. In the fatty acid composition of corn oil, saturated fatty acids account for 15%, unsaturated fatty acids account for 85%, and unsaturated fatty acids are mainly oleic acid and linoleic acid. Corn oil is rich in vitamin E and has good thermal stability.
? major constituent
The unsaturated fatty acid content is as high as 86%, and its fatty acid composition is similar to soybean oil. Its advantage is that the content of vitamin E is higher than that of ordinary vegetable oil, and it contains a certain amount of antioxidant substances.
? nutritive value
1), corn oil is rich in vitamins A, D and E, which is easy for children to digest and absorb;
2) Linoleic acid in corn oil can play a health care role for patients with cardiovascular and cerebrovascular diseases;
3) It also contains a certain amount of antioxidant substances, which are beneficial to the skin and anti-aging.
? Health reminder
1), corn oil can be used for cooking and cold salad;
2), not very heat-resistant, suitable for cooking with short heating time or heating temperature less than smoke point.
7. Sunflower oil
Sunflower oil, also known as sunflower seed oil, is abundant in the former Soviet Union, Canada and the United States. It is also produced in large quantities in Northeast China and North China. Sunflower seed oil is rich in vitamin E and chlorogenic acid, and its oxidation stability is very good.
major constituent
The composition of fatty acids in sunflower oil is influenced by climatic conditions. Sunflower oil produced in cold areas contains about 15% oleic acid and about 70% linoleic acid. Sunflower seed oil produced in warm areas contains about 65% oleic acid and 20% linoleic acid.
? nutritive value
It contains a lot of unsaturated fatty acids such as linoleic acid, which can promote the regeneration and growth of human cells, protect skin health and reduce the accumulation of cholesterol in blood.
Health reminder
1), which has higher antioxidant capacity and better heat resistance than soybean oil;
2), suitable for low-temperature stewing, but not suitable for frying food alone.
8. Sesame oil (sesame oil)
Sesame oil is one of the oldest edible oils in China, and its output ranks first in the world. Sesame oil is generally not used for cooking, but is usually used as cold oil. It mainly contains fatty acid, linoleic acid and arachidic acid.
major constituent
It contains 35.0% ~ 49.4% oleic acid, 37.7% ~ 48.4% linoleic acid and 0.4% ~ 1.2% arachidonic acid.
? nutritive value
Regular consumption of sesame oil can regulate capillary function, enhance the ability of tissue to absorb oxygen, improve blood circulation, promote gonadal development and delay aging.
9. tea oil
Tea oil is a kind of vegetable oil extracted from wild camellia fruit. Because it does not contain any chemical fertilizer and has no pollution, it has become the first health plant edible oil promoted by FAO. It mainly contains oleic acid, linoleic acid, linolenic acid, palmitic acid and stearic acid, and does not contain cholesterol, aflatoxin and additives.
major constituent
Its fatty acid composition is similar to olive oil, in which unsaturated fatty acids account for more than 90%, monounsaturated fatty acids account for 80-83%, and it is also rich in vitamin E.
? nutritive value
1), which is close to the natural fat of human milk, is an excellent food suitable for infants;
2) Vitamin E and antioxidant components in it have the beauty effect of skin care;
3) Its reasonable fatty acid ratio is helpful to improve the blood lipid pattern and reduce the risk of cardiovascular diseases, so it is regarded as a kind of oil with high nutritional value.
? Health reminder
1), refined tea oil has good flavor, storage resistance and high temperature resistance, and is suitable for cooking oil and frying oil;
2) It can also replace olive oil for cosmetics and skin care.
10, walnut oil
Walnut oil is an edible oil squeezed from walnut kernel, which belongs to high-grade health-care edible oil and is not suitable for frying, because high temperature will destroy its nutritional value, and it is only used for cold salad and seasoning. Contains fatty acids, linoleic acid, etc.
rap oil
Mustard rapeseed oil is a healthy edible oil, which contains high unsaturated fatty acids and can effectively reduce the incidence of cardiovascular and cerebrovascular diseases.
1 1, olive oil
Dark green, rich in vitamins, minerals, protein, essential fatty acids, especially ALA(α linolenic acid). Suitable for preparing ointment, suppository, injection oil, etc. Applications: rheumatism symptoms, hair care and cosmetics; It can calm and protect hair. It is helpful for inflamed and pink skin. Because the smell is strong, it is more useful for the essential oil with strong smell. Traditionally, it has been used to make slimming oil.
Rich in unsaturated fatty acids and vitamin E, it can be absorbed by the skin, moisturize and nourish the skin, make the skin shiny and elastic, promote blood circulation and skin metabolism, help to lose weight, reduce wrinkles and delay aging.
It has excellent permeability, contains extremely high vitamins and minerals, accelerates the treatment of skin damage and eczema, and is suitable for dry and aging skin. Olive oil is squeezed and contains a lot of unsaturated fatty acids. Eating (olive oil) has a good effect on heart disease and has a soothing effect on sunburn. Can be used for treating weight loss, aging and sunburn.
Olive oil is rich in unsaturated fatty acids and vitamins, which is easily absorbed by the skin, refreshing and natural, and has no greasy feeling. It is a pure natural beauty product, known as "edible skin care product", especially in preventing dry skin and itchy skin in autumn and winter, eliminating wrinkles around eyes, smoothing skin and brightening hair. It is an excellent maintenance product. Olive oil originated in the Mediterranean generation and is praised by westerners as "liquid gold", "queen of vegetable oil" and "Mediterranean manna". It is the only woody plant oil in the world that can be eaten by people in a natural state. Rich in monounsaturated fatty acids, progesterone and β-carotene, it can promote blood circulation, improve the function of digestive system, strengthen the body, beauty beauty and resist aging.
? major constituent
The total amount of vitamin A, vitamin D, vitamin E and unsaturated fatty acids in olive oil exceeds 80%. Among them, oleic acid accounts for 86%, linoleic acid accounts for 1% ~ 5%, and arachidic acid accounts for 0.9%. The digestibility of human body can reach about 94%.
? nutritive value
Olive oil is recognized as the best edible oil in the world, which can reduce blood fat and cholesterol, prevent all kinds of cancers, and has a very good cosmetic effect.
? Health reminder
1), olive oil is fragrant and delicious for cold salad, and it is no problem for cooking and stewing;
2) The adulteration of imported olive oil is quite common in the market, and it is difficult for ordinary people to taste it, so be careful when buying, and never be greedy for petty gains.
Third, buying skills
1, smell. Should have the inherent fragrance of vegetable oil (such as peanut oil, sesame oil, rapeseed oil, etc.). ), if there is an odor, it may be a product with excessive acid value and peroxide value.
2. Look at the appearance. Edible vegetable oil with good product quality and high refining degree should be clear and transparent, have the unique color of this variety and contain no impurities.
3. Look at the price. When buying, compare the prices of similar products from different enterprises. For example, the price of peanut oil is generally 100 yuan /5L, and individual products are from 60 yuan. Therefore, we should pay attention to the name and ingredient list of this product, whether it has the same name or not, and whether it is mixed with other cheap vegetable oils to mislead consumers.
4. Look at the label. When purchasing, the products of large or well-known brand enterprises should be selected, and the labels such as product name, ingredient list, net content, implementation standard, production date, shelf life, factory name, product grade, genetically modified or not, and storage conditions should be complete. Pay special attention to the ingredient list. There should be only one raw material in the ingredient list of pure vegetable oils such as peanut oil, soybean oil, sesame oil and olive oil. There are many kinds of raw materials in the ingredient list of blended oil, so pay attention to the order of raw materials, which proves that there are many ingredients in the oil.
5. Learn simple identification methods. If it is peanut oil, you can use the low temperature travel method. Adjust the refrigerating room of the refrigerator to about 10℃, take a proper amount of peanut oil and put it in 10 minutes. Half of the pure peanut oil has begun to solidify, and the peanut oil mixed with a lot of soybean oil has only slightly solidified at the bottom.