Cooking oil is an indispensable part of our daily diet. So how should we use oil? Read on—
It is estimated that China returns 2 to 3 million tons of gutter oil to dining tables annually, while the country's total annual consumption of animal and vegetable oils is about 22.5 million tons. This means that for every 10 meals we eat, one might contain gutter oil. While guarding against the "attack" of waste oil, the use and storage of healthy oil also require significant knowledge.
Myth 1: No smoke from the oil, no food in the pan.
People are accustomed to the practice of not adding food to the pan until the oil smokes, and cooking over high heat. When stir-frying, they heat the oil until it billows with smoke, then put the wet vegetables into the hot oil, accompanied by a sizzle, which seems to give them a sense of accomplishment in cooking. In fact, this is the worst method. Because excessive heating of vegetable oil can destroy the lecithin and vitamins A, E, etc., in the edible oil. At the same time, high-temperature oil can also produce potential carcinogenic substances such as high-temperature oxidation polymers, nitrosamines, polycyclic aromatic hydrocarbons, heterocyclic amines, and acrylamide. Cooking fumes are a contributing factor to lung cancer and can also lead to respiratory diseases such as pneumonia and asthma. The scientific method for stir-frying is to pour the oil into the pan, wait for the oil's surface to ripple with little smoke (the optimal oil temperature is about 90°C), and then add the vegetables.
Myth 2: Plastic barrels can be used to store oil long-term.
Healthy oil should be used, and the container for storing oil must also be scientific. Almost all brands of cooking oil in plastic barrels contain two plasticizers: dibutyl phthalate and dioctyl phthalate. These chemical components have been proven to be highly toxic to the hearts, livers, lungs, and kidneys of rats, with a particularly significant impact on their testicles. The testicles of rats contaminated with plasticizers can shrink by nearly one-third to half, and the number and activity of their sperm are reduced to varying degrees. As long as plastic products containing plasticizers are in contact with oil, the plasticizers will dissolve into the oil. Moreover, the more plasticizer in the plastic, the longer the contact time with the edible oil, and the higher the storage temperature, the more plasticizers will dissolve. Therefore, when storing oil daily, it is best to use glass, iron, ceramic, and other containers to hold cooking oil, and store it away from light and oxygen. Do not use plastic barrels for long-term storage, and try to buy small bottles to ensure they can be used up in a short period.
Myth 3: Reused oil is still edible.
In addition to the above misconceptions, there may also be some misunderstandings regarding the choice of oil.
Perennial Oil: This refers to the oil used repeatedly for frying foods, such as for frying dough twists, youtiao (fried dough sticks), glutinous rice balls, fish, and chicken. Because this oil is reused many times, it is called perennial oil. This oil is often overheated and reheated multiple times, and its prolonged use leads to fatty acid oxidation. Oxidized oil seriously affects health and can easily lead to obesity, diabetes, and trigger hypercholesterolemia and coronary heart disease.
Gutter Oil: As the name implies, this is oil collected from restaurant drains. In addition to the unhealthy factors of perennial oil, this oil also contains bacteria, toxins, and heavy metals. Long-term consumption may induce cancer and is extremely harmful to the human body.
Saliva Oil: This is the oil from dishes after a diner (A) has eaten, which is then recycled and given to another diner (B). It is often found in spicy hot pot, boiled tripe, etc. These oils are reused after being directly collected, and in more extreme cases, even used chili peppers are collected for subsequent diners. If any diner has an infectious disease, these diseases can continue to spread through this food.
Recycled Oil: This is oil collected from drippings of roast duck, roast chicken, and Turkish kebab, which is then supplied to street stalls, small restaurants, and even employee canteens. The danger of this oil lies in its本质 (nature) as peroxidized lipids, and its residue is charred protein, containing heterocyclic amines. Heterocyclic amines belong to strong carcinogenic, teratogenic, and mutagenic substances.