The refining process of waste oil is simple and it takes only three steps to turn it into edible oil.
According to statistics, China consumes about 22 million tons of oil every year, of which 15% is about 3.3 million tons of waste oil. With the sharp rise in the price of edible oil in recent years, the net profit of processing kitchen waste oil is also increasing, and many criminals take risks for this. For the "oil refining" process involved in the case just seized, the police recently said that it can be done only by simple physical separation in three steps: hydrolysis, distillation and splitting. Previously, what some experts called "complicated technology" was misleading.
"The collection of waste oil itself is not illegal, because it can also be used for industrial purposes such as refining biodiesel." Lin Dong, member of the Standing Committee of Ninghai County Committee of Ningbo City, Zhejiang Province and director of the Public Security Bureau, said recently.
"This is also the main difficulty in case detection." Fan Jianfu, political commissar of Ninghai County Public Security Bureau, said, "If waste oil is used for legal purposes, it will turn waste into treasure. Obtaining evidence of processing into edible oil sales is the key to solving the case. "
The reporter learned that in food safety cases such as tainted milk powder and clenbuterol, the administrative department has strengthened the inspection of food, which is the main discovery channel of toxic and harmful food cases and plays an irreplaceable role in cracking down on crimes by public security organs. "However, based on the indicators such as chromaticity, water content and acid value index of the current edible oil detection, the so-called edible oil refined from waste oil is tested, which is all qualified." Feng Weifeng, squadron leader of the Public Security Action Squadron of the Public Security Brigade of Ninghai County Public Security Bureau, said.
Coordinated by the Public Security Administration of the Ministry of Public Security, relevant food experts have initially detected that the edible oil refined from waste oil contains a variety of toxic and harmful components, some of which can also cause cancer.
Hong Jufeng, deputy instructor of the Public Security Brigade of Ninghai County Public Security Bureau, said: "The breakthrough of these two difficulties has made the fact that waste oil flows to the table more and more clear. Therefore, although the company involved is dressed as a green high-tech enterprise and has used various anti-investigation methods, it has not escaped the police’s eyes. "
A large amount of evidence held by the police fully proves that the process of refining edible oil with waste oil is only a simple physical separation, which is roughly divided into three steps: hydrolysis, distillation and splitting, which is completely different from the chemical reaction process of refining biodiesel. Previously, some experts said that "the technology of refining edible oil with waste oil is complicated, which is difficult for ordinary people to master, and the refining cost is expensive and not worth the loss", which is misleading.
"The biggest harm of gutter oil does not come from the word’ gutter’, but from the words’ multiple heating’ and’ oxidation’." Fan Zhihong, a professor at Food College of China Agricultural University, said that most of the recovered cooking oil and frying oil have been heated repeatedly, while liquid vegetable oil is not heat-resistant. When cooking and frying, the oil temperature can reach 160℃ ~ 300℃, and at this time, trans-isomerization, peroxidation, thermal cracking and other reactions will occur in oil.
This high temperature process has two effects on the quality of oil: first, some nutrients that oil itself should have will be destroyed, such as vitamin E and some fatty acids necessary for human body; Second, harmful trans fatty acids will continue to increase, and the saturated fat of oil will increase. "What is such a bad oil? You can see that there are some semi-solidified oil in the oil box of the range hood, which is the final result of oxidative polymerization of oil after overheating. Eating this repeatedly heated oil can easily lead to many diseases, such as fatty liver, hyperlipidemia, hypertension, stomach problems, and may even increase the risk of heart disease and various cancers. "
In life, we always inevitably go to restaurants. What is the food made from "gutter oil"? Fan Zhihong said that after repeated heating of oil, the most intuitive feeling is a little greasy. Take these vegetables home and put them in the refrigerator. The oil will solidify and will not melt even at room temperature. Moreover, it will be more difficult to wash dishes after eating.
Jiang Kun, the executive chef of a restaurant in Beijing, said that to judge whether the oil in the dish is gutter oil, you can first look at the state of the oil in the dish. Generally, vegetable oil used for cooking is mostly watery, which is not sticky and will not adhere to vegetables. However, the gutter oil itself has been processed many times, and then it will solidify when it is cooked, which will be like being attached to vegetables. At the same time, if the mass-produced waste oil wants to be served on the table again, it is necessary to use some chemical methods for fine processing, which will lead to discomfort in the gastrointestinal tract of consumers, usually feeling bloating, indigestion, and severe diarrhea.
Earlier, it was reported that some "gutter oil" could reach the national standard after fine processing, and finally entered the supermarket. In this regard, the reporter interviewed Mr. Wang, the person in charge of a food inspection agency. In his view, although this is a bit sensational, there is indeed a certain possibility in theory. "Because the composition of waste oil itself is more complicated, and the refining technology of edible oil is constantly improving, some unscrupulous traders have reduced some indicators of bad oil to the standard of edible oil through scientific and technological means. At present, from the point of view of the finished oil, there is really no good inspection method to judge whether this oil is edible oil, only to find the reason at the source. " He said.
"There are some standards for testing edible oil, such as trans fatty acids, acid value and peroxide value, but these standards are not enough to judge whether it is waste oil." Mr. Wang said that trans fatty acids, for example, also exist in some good edible oils, such as palm oil. The acid value of waste cooking oil is relatively high, and it can also reach normal level through treatment, as well as peroxide value.
One is the lack of standards. For example, from the appearance and color, it is difficult to distinguish edible oil refined from normal edible oil. At present, the country does not have a clear identification standard for what gutter oil is. If we only follow the existing edible oil standards, we may even get the absurd result that gutter oil meets the standards.
Second, the supervision is weak. In the case of illegal cooking oil detected by the police, we have not seen the relevant administrative law enforcement departments in all aspects, such as fishing, crude refining, reselling, deep processing, wholesale and retail.
Third, the export is not smooth. As long as there is kitchen waste, there will be gutter oil, which can be used as raw materials for the production of biodiesel and other chemicals, but why should Green Company take the risk to produce edible gutter oil? "Because the biodiesel we produce can’t be sold at all. If gas stations around the country don’t accept it, our products will not sell. " Liu Liguo, the actual operator of Green Company, said.
It is not a day or two since the problem of cooking oil was exposed. The General Office of the State Council issued the Opinions on Strengthening the Renovation of Cooking Oil and the Management of Kitchen Wastes. However, through the cracked cases, people were surprised to find that the black dens producing edible cooking oil were covered with the cloak of regular factories, and mechanized large-scale production was realized, and the sales channels were more concealed, which showed that the black economic chain of cooking oil was becoming more and more rampant.
The "industrial upgrading" of the production and sale of edible waste oil from small workshops to large factories reflects the lack of regulatory mechanisms and measures. In this case of waste oil detected by the police, the regulatory authorities have not been seen in all aspects such as fishing, crude refining, reselling, deep processing, wholesale and retail. Such a lack of supervision has increased social worries about the safety of edible oil.
The rampant gutter oil exposes the disadvantages of territorial supervision. At present, China’s food safety is regulated according to the territory, and cross-regional supervision has basically become no matter who in many places. Once the waste oil industry chain puts different links in different regions, such as purchasing crude oil from Sichuan, Zhejiang and other places, deep processing in Shandong and other places, and selling it to Henan and other places, the supervision of "cleaning the snow before the door" will lose its effect.
It is the duty of regulatory authorities at all levels to crack down on the black industrial chain of waste oil and prevent it from poisoning people’s health. The recent cracking of this extraordinarily serious case by the public security organs shows that no matter how difficult the investigation is and how strong the criminals’ anti-investigation ability is, as long as they comply with the people’s voice for food safety and find the right direction of work, they will always find a good way to crack down on the crime of gutter oil.
It is quite urgent to establish a network managed by all departments. If all functional departments can share resources and work together, they will resolutely investigate and deal with clues suspected of manufacturing and selling gutter oil; At the same time, fully mobilize the enthusiasm of the public, set up a special reporting and complaint platform to facilitate the masses to provide clues, and the action against gutter oil will surely achieve more outstanding results. This edition is based on Xinhua News Agency and Beijing News (Source: Peninsula Network-peninsula metropolis daily) [Editor: Photographic Department].