Disadvantages: Garbage oil is a kind of non-edible oil, with poor quality and extremely unsanitary, and its peroxide value, acid value and moisture content seriously exceed the standard. Containing toxins, flowing into rivers will cause eutrophication of water bodies. Once eaten, it will destroy white blood cells and digestive tract mucosa, cause food poisoning and even cause cancer. Frying oil, one of the "vegetable oils", 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, polymerization, etc., which increases the viscosity of the oil, deepens the color, increases the peroxide value, and produces some irritating substances such as volatiles, aldehydes, ketones and lactones, which have carcinogenic effects. The toxicity of aflatoxin, the main hazard in swill oil, is 100 times that of arsenic.
First, so is the sewer. Gutter oil is the residue of domestic oil accumulated in sewers for many years. Nowadays, many black-hearted traders go to restaurants and other places that use a lot of cooking oil to take out the oil that people washed into the sewer from their ditches and then reuse it directly. ...
Second, there is no obvious difference in color and taste between mixed gutter oil and general bulk edible oil.
Thirdly, according to the experimental determination, the rancidity index of "gutter oil" far exceeds the national regulations. If people take it for a long time, they will lose weight and suffer from developmental disorders, diarrhea and enteritis, as well as liver, heart and kidney enlargement and fatty liver. In addition, the aflatoxin produced by contaminated gutter oil is not only easy to cause liver cancer, but also can cause tumors in other parts, such as gastric adenocarcinoma, renal cancer, rectal cancer, breast cancer, ovarian cancer, small intestine and other cancerous gutter oil. Edit this paragraph to identify: Once the waste oil enters the market, consumers should learn sensory recognition. 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 be reduced due to the mixing of alkaline grease, wax and impurities in the production process; Look at the color, pure oil is colorless, in the production process, because the pigment in the oil dissolves in the oil, the oil will have color; Look at the sediment, its main component is impurities.
The second taste. Each oil has its own unique smell. You can put a drop or two of oil on your palm, rub your hands together and smell it carefully while it is hot. Odd oil indicates that there is a problem with the quality, and it is likely to be smelly waste oil; You can't buy it if it smells of mineral oil.
Three flavors. Take a drop of oil with chopsticks and taste it carefully. Oil with sour taste is unqualified, oil with bitter taste has been rancid, and oil with peculiar smell may be "gutter oil".
Listen 4: Take one or two drops of oil from the bottom of the reservoir, spread it on flammable paper, ignite it and listen to its sound. Products with normal combustion and no noise are qualified products; If the combustion is abnormal, it will make a "squeaky" sound, indicating that the water content exceeds the standard and it is an unqualified product; When burning, there is a "crackling" explosion, indicating that the water content of the oil is seriously exceeding the standard, which may be an adulterated product and must not be purchased.
Five questions: ask the merchants about the purchase channels, ask for the purchase invoices or check the sampling inspection report of the local food hygiene supervision department if necessary.
The quick detection method of gutter oil edits the quick and accurate detection method in this paragraph: the relationship between the concentration of metal ions and the conductivity is used to judge the amount of metal ions in the oil by detecting the conductivity of the oil. Many experiments show that the conductivity of waste cooking oil is 5 to 7 times that of first-class edible oil, so it can accurately identify waste cooking oil. Gutter oil is actually a general concept, which is a general term for all kinds of inferior oils in people's lives.
Waste oil can be divided into three categories:
One is gutter oil in a narrow sense, that is, oily floating objects in sewers or leftovers from hotels and restaurants (commonly known as swill) are simply processed and refined;
The second is the oil produced by the processing and refining of inferior pork, pig offal and pig skin;
Third, the oil used for fried food should be reused after being used more than the specified number of times, or after adding some new oil to the oil.
When law enforcement officers check, they use the test paper for rapid detection of edible oil rancidity to compare whether the peroxide value and acid value of the detected oil exceed the standard, and once it exceeds the standard, it can be determined that it is a problem oil.