Since when, the sewers in China city have become a shortcut for some criminals to get rich. They get a lot of turbid and unpleasant "paste" from it every day. Only after simple filtration, heating, precipitation and separation can these stinking garbage become "edible oil" on the table of citizens, which is also commonly known as "gutter oil".

How to identify waste oil;

look

Transparent and pure vegetable oil is usually transparent, and its transparency will be reduced due to the mixing of alkaline grease, wax and impurities in the production process. Pure oil is colorless, and the oil will be slightly colored during the production process because the pigment in the oil is dissolved in the oil.

Deep object

Its main component is impurities. Good oil must look transparent, and the more transparent the color, the better. Deep cooking oil is not good, it is recommended not to buy it.

brand

Consumers go to the supermarket to buy edible oil and choose edible oil produced by big brands. Quality is relatively guaranteed, and quality problems are easier to claim.

raw material

Vitamin e is an effective component of the same kind. The higher the unsaturated fatty acid content, the better the oil. You can compare the contents marked when you buy.

smell

Each oil has its own unique smell. You can put a drop or two of oil on your palm, rub your hands and smell it when it is hot. For example, peanut oil will taste like peanuts; Olive oil will smell like olives. The gutter oil has no fragrance of the oil finger itself. If you smell it carefully, you can smell a little sour, a strange smell of chemical components, and even a bad smell.

taste

Take a drop of oil with chopsticks and taste it. Oil with sour taste is unqualified, oil with bitter taste indicates that the oil has been rancid, and oil with peculiar smell may be gutter oil.

listen to

Take a drop or two of oil from the bottom of the oil tank, spread it on flammable paper, and listen to its sound after ignition. Normal combustion without sound is a qualified exit; Incorrect combustion, with a "squeak" sound, indicating that the water content exceeds the standard and it is an unqualified product; When burning, it makes a "click" sound, indicating that the water content of the oil is seriously exceeding the standard, which may be an adulterated product and must not be purchased.

ask

Ask the merchant about the evolution channel, ask for the purchase invoice or check the sampling test report of the local food and drug administration if necessary.

Effect of waste oil on human health

Fan Zhihong, a professor at the College of Food Science and Nutritional Engineering of China Agricultural University, believes that the biggest harm of gutter oil lies not only in the carcinogenic aflatoxin, but also in the words "multiple heating" and "oxidation". Huiju Zhihong said that in restaurants, many ingredients need to be oiled, and many delicacies and snacks need to be oiled, which will inevitably lead to repeated heating of oil. Vegetable oil is not heat-resistant. When cooking, chemical reactions such as thermal oxidation will occur at the high temperature of 160-300℃, which will lead to the loss of nutrients such as vitamin E and fatty acids. Oil without nutrition is already "bad oil", and harmful trans fatty acids and saturated fats will continue to increase. Studies have shown that eating this repeatedly heated oil is related to fatty liver, hyperlipidemia, hypertension, cholecystitis and stomach diseases. It may even increase the risk of heart disease and various cancers.

Teach you to avoid gutter oil:

Although there is no effective method to identify waste oil at present, from the perspective of personal health, we can start with the following points:

1, eat less oil. When eating out, order more cooked food and less greasy, including fried staple food, crispy and fragrant dishes. It should be noted that although some tea leaves do not need to be fried, they also need to go through the process of "oiling", such as those specially tender diced meat and chicken. Only when people eat less oil can the raw materials recovered from waste edible oil be less, which can reduce the production of waste edible oil from the source.

2, too greasy oil should be vigilant. When eating out and finding dishes greasy and sticky, it is more likely to use gutter oil or inferior oil. Fresh and qualified vegetable oil, smooth and easy to flow, no greasy feeling. If you wash it with water, the oil will be washed off more easily. Repeated use of inferior oil tastes sticky, has no refreshing feeling, and is even difficult to wash off in hot water.

3. Large chain restaurants are safer. Although some media have revealed that some high-end hotels and restaurants use gutter oil, on the whole, these places are relatively safe. Chain restaurants pay more attention to their own brands. If they are caught using gutter oil, their reputation will collapse like dominoes, so they will be cautious.

4, use the refrigerator to identify. After packing the vegetables, put them in the refrigerator and take them out a few hours later. If the oil has solidified or semi-solidified, it means that the quality of the oil is poor, and the content of trans fatty acids and saturated fatty acids is high, which is likely to be oil that has been heated many times, or even waste oil. It's better to get rid of such leftovers, and don't go to such a restaurant for the second time.

5. Don't buy bulk oil. Bulk edible oil mixed with peanut oil and soybean oil is the main sales channel of edible oil. Instead, consumers should go to large supermarkets to buy regular brands, QS certification or organic certification of edible oil.