How to identify waste oil

Waste oil is actually a general concept, which is a general term for all kinds of inferior oils in people's lives. Generally speaking, gutter oil can be divided into the following categories: first, gutter oil in a narrow sense, that is, the oily floating objects in sewers or the leftovers and leftovers of hotels and restaurants (commonly known as swill) are simply processed and refined; Second, the oil produced by processing and refining inferior pork, pig offal and pig skin; Third, the oil used for fried food is reused after the number of uses exceeds the specified requirements, or the oil is reused after adding some new oil to it.

Once "gutter oil" enters the market, consumers should learn to identify it by senses. According to experience, edible vegetable oil can be identified by looking, smelling, tasting, listening and asking.

take a look. Look at the transparency, pure vegetable oil is transparent, and the transparency will decrease due to the mixing of alkali grease, wax and impurities in the production process; Look at the color, pure oil is colorless, and the oil will be colored because the pigment in the oil is dissolved in the oil in the production process; Look at the sediment, its main component is impurities.

second smell. Each oil has its own unique smell. You can drop a drop or two of oil on your palm, rub your hands together, and smell it carefully when you are hot. Oil with odor indicates that there is a problem with the quality, and it is likely to be waste oil with odor; If there is a smell of mineral oil, you can't buy it.

three tastes. Take a drop of oil with chopsticks and taste it carefully. The oil with sour taste is unqualified, the oil with bitter taste has been rancid, and the oil with peculiar smell may be "waste oil".

four listening: take one or two drops of oil from the bottom of the oil layer, spread it on flammable paper, light it and listen to its sound. The products with normal combustion and no noise are qualified products; If the combustion is abnormal and makes a "squeaky" sound, the water content exceeds the standard and it is an unqualified product; When burning, it makes a "crackling" explosion, indicating that the water content of the oil is seriously exceeding the standard, and it may be an adulterated product, so it is absolutely impossible to buy it.

five questions: ask the merchants about the purchase channels, and if necessary, ask for the purchase invoice or check the sampling inspection report of the local food hygiene supervision department. Potential hazards of "gutter oil"

Garbage oil is a non-edible oil with extremely poor quality and unsanitary peroxide value, acid value and water content exceeding the standard. It contains toxins, which will cause water eutrophication when flowing into rivers. Once eaten, it will destroy white blood cells and digestive tract mucosa, cause food poisoning and even cause cancer. Fried oil, one of the "vegetable oil", is repeatedly used at high temperature for a long time, and comes into contact with oxygen in the air, resulting in complex reactions such as hydrolysis, oxidation and polymerization, which increase the viscosity of the oil, deepen the color, increase the peroxide value, and produce some volatiles, aldehydes, ketones, lactones and other pungent substances, which have carcinogenic effects. Aflatoxin, the main hazard in hogwash fat, is 111 times more toxic than arsenic.

According to reports, the state has corresponding standards for the hygienic quality of edible oil, and has clearly defined relevant indicators.

So, if the content of related ingredients in edible oil exceeds the standard, what harm will it cause to people? Food hygiene experts in the health department explained this in detail.

aflatoxin: The highly toxic aflatoxin in swill oil is the strongest chemical carcinogen found at present, and its toxicity is 111 times that of arsenic. Animals who ingest aflatoxin in low doses for a long time will suffer from liver cancer. Aflatoxin may also cause gastric adenocarcinoma, renal cancer and cancer in breast, ovary and small intestine.

benzopyrene: it is also a strong carcinogen, which can cause gastric cancer and intestinal cancer.

Arsenic is a heavy metal. If it remains in excess in the body, it will cause headache, dizziness, insomnia, dreaminess, fatigue, indigestion, emaciation, liver discomfort and other symptoms.

lead: a kind of heavy metal, if absorbed excessively in the body, will lead to hemolysis, lead-induced encephalopathy and peripheral neuropathy, and cause severe abdominal cramps, anemia, toxic liver disease, toxic nephropathy and multiple peripheral neuropathy.

In addition, the repeatedly processed hogwash fat also contains a lot of tolualdehyde and phosphorus (from dishwashing detergent). Once eaten by human body, it will destroy white blood cells and digestive tract mucosa, cause food poisoning and even cause cancer.