"Oil" is a daily necessity, so its scientific usage is crucial for human health. Improper use, accumulating over time, can even lead to cancer. Professor Hong Zhaoguang, a renowned cardiovascular expert in China, has offered advice on common misconceptions people have regarding dietary oil.
Misconception 1: High-temperature stir-frying
Many people prefer to stir-fry at high temperatures, waiting until the oil in the wok smokes before adding ingredients. This practice is unscientific. High temperatures not only destroy the nutritional value of food but also produce peroxides and carcinogenic substances. It is recommended to heat the wok first, then add the oil, and begin stir-frying immediately without waiting for the oil to smoke.
Misconception 2: Not consuming animal oil
A complete absence of oil can lead to deficiencies in vitamins and essential fatty acids, affecting human health. It is also not advisable to exclusively consume vegetable oil and completely avoid animal oil. In appropriate amounts, animal oil (saturated fatty acids) is beneficial to the human body.
Misconception 3: Using only a single type of oil long-term
Currently, it is difficult for most families to use different oils for different dishes. However, it is best to alternate between several types of oil or switch oils after a period of time, as it is rare for a single oil to meet all the body's lipid needs.
Misconception 4: No difference in oil use for people with abnormal blood lipids or weight
For individuals with abnormal blood lipids or abnormal weight, it is more important to choose vegetable oils high in monounsaturated fatty acids. The amount of oil used should also be controlled. For people with normal blood lipids and weight, the total daily oil intake should not exceed 25 grams, with polyunsaturated and monounsaturated fatty acids each accounting for about half. For the elderly, those with abnormal blood lipids, the obese, those with obesity-related diseases, or individuals with a family history of obesity, their daily per-person oil intake should be even lower, possibly reduced to 20 grams.
Tips: Selecting Cooking Oil:
When purchasing cooking oil, first, check the grade. According to the latest standards, cooking oil is divided into four grades, with the fourth being the lowest. Second, check the origin, which primarily refers to the source of the raw materials. Third, check the raw materials to see if they are genetically modified. Fourth, check the production method, i.e., whether the oil is produced by "pressing" or "extraction." Pressed oil can retain the original nutrients of the raw material and has a purer quality.
The quality of cooking oil is mainly reflected in its color, aroma, clarity, and taste.
Color: High-quality soybean oil is deep yellow, while ordinary soybean oil is pale yellow. Rapeseed oil is yellowish-green or golden yellow. Peanut oil is pale yellow or light orange, and cottonseed oil is pale yellow.
Aroma: Dip a finger in the oil, rub it on the palm, and then smell it. High-quality oil should have its own characteristic aroma depending on the type, without any other strange odors.
Clarity: High clarity indicates less moisture and impurities, meaning better quality. Good vegetable oil should be clear and transparent after being left undisturbed for 24 hours, without being turbid, precipitated, or having suspended matter.
Taste: Dip a chopstick in a little oil and taste it. It should not have any bitter, scorched, or rancid off-flavors.
It is worth noting that there are individual cases where "the oil varies." Salad oil should be clear, transparent, colorless, or pale yellow. Peanut oil, soybean oil, rapeseed oil, etc., are semi-transparent in pale yellow to orange-yellow. Sesame oil is orange-yellow or brownish. Crude oil, obtained from preliminary processing of soybeans, rapeseed, peanuts, sesame seeds, etc., is dark in color, turbid, and not suitable for consumption. If vegetable oil has poor clarity, increased viscosity, or bubbles, it is often a sign of spoilage. Peanut oil solidifies into an opaque state in low winter temperatures, which is a normal phenomenon and should be distinguished during inspection.