Experts say that cooking oil is frequently degraded and prone to oxidative deterioration and may cause cancer

A project of Guangdong Gongda found:

The edible oil is frequently poured and easily oxidized

Experts pointed out that the shelf life of many food products is actually unopened, and there is no standard for oxidation safety after opening.

Many people misunderstand the “shelf life” and many couples will buy a large barrel of edible oil and eat it at home. This practice may increase the risk of chronic diseases and seriously damage health. Recently, a subject of Guangdong University of Technology has found that individual brands of edible oil are deteriorating within one month after opening and may produce carcinogenic oxidation products.


Individual edible oils are oxidized or carcinogenic


Teachers and students of Guangdong University of Technology in the “Oxidation Safety of Bottled Edible Oil After Opening” topic, randomly selected several brands of edible oils from the market, and simulated the preservation conditions and usage habits of ordinary families, and constantly opened bottles. Dumping, sampling and testing regularly, found that these unsealed oils were oxidized by acceleration, and there was no problem of oxidative deterioration even before the shelf life.


The degree of oxidation of individual brands of edible oil within one month after opening in Kaifeng exceeds the national hygiene standards. The important nutrients contained in vitamin E, including vitamin E and essential fatty acids, are destroyed, and the oxidation products produced are harmful to the human body. , increase the risk of chronic diseases such as coronary heart disease, may also cause cancer or accelerate aging.


Professor Wu Kegang, deputy director of the Department of Food Science and Bioengineering at Guangdong University of Technology, said that the bottled oil of these big brands, if unopened, should have no problem in quality within the warranty period. China has strict standards in this regard, but it is in Kaifeng. There is no standard for post-oxidation safety issues and there is a regulatory gap.


He introduced that not only cooking oil but also the issue of oxidation safety after opening is also present in other foods with long consumption cycles, such as soy sauce and sauces. Some daily necessities with long life cycle also have this problem. For example, many families like to buy shower gels or shampoos that use large packages. Sometimes they are used to find that the smell becomes unpleasant. This is the result of deterioration of the product.


People generally misunderstand shelf life


Prof. Wu Kegang reminded the public that the shelf life of bottled cooking oil represents the time it can be stored without being opened. It does not mean that it can be kept for so long after opening, and many consumers have misunderstandings in this respect.


Reporters on the edible oil consumption habits and the understanding of the shelf life and other issues, when a random visit to some families in Guangzhou found that the vast majority of people have a stronger sense of "shelf life", most of the food has passed the shelf life are discarded and not eaten. However, most of them have a vague understanding of the concept of “shelf life”, and think that the food in the shelf life should be safe.


Big barrel oil is recommended in the oil


"Oxidation of the oil after the color and the normal oil is not different, and sometimes the taste is not obvious, so that consumers are not aware." Professor Wu explained. How to eat food oil safe? He suggested that Kaifeng’s oil should be eaten as soon as possible. It is best to buy small packaged cooking oil for households with small population or infrequent cooking. If you buy vats of cooking oil, keep it in a cool place and avoid frequent opening. For daily use.


During the interview, some consumers suggested that whether or not they can mark the barrel of edible oil, “the shelf life after opening,” to facilitate the public's reference.


According to reports, the Hong Kong Edible Oil Industry Association is preparing to implement an “edible oil certification scheme” to carry out at least one test every six months on oxidation indexes such as peroxide values ​​and free fatty acids, and to pass on two consecutive inspections of edible oil products and stick them on labels. For public reference. Reporter Chen Hui