The safety of self extracted fresh oil is a concern

With the increasing awareness of people's health and food safety, a trend of "extracting good oil by oneself" has gradually emerged in the past two years. Either buying an oil press at home to extract oil, or taking oil to nearby small-scale workshops to extract oil, can this really eliminate gutter oil and make eating safer and healthier? In fact, the result may just go the opposite way.

Squeezed bulk peanut oil with excessive carcinogens

Earth pressed peanut oil is popular among consumers due to its "no additives" and "pure natural" properties. But the safety of bulk peanut oil squeezed by some small workshops using local methods is a concern. The investigation found that some small workshops severely exceeded the standard of aflatoxin B1 in bulk peanut oil, with the highest exceeding the standard by nearly 15 times. Aflatoxin B1 has strong carcinogenicity and can accumulate in the human body. Long term low-dose intake will greatly increase the probability of developing liver cancer.

Why is soil pressed peanut oil prone to excessive carcinogenic substances?

This is closely related to the raw materials of peanut oil, especially the storage conditions of peanuts. Peanuts and their products are one of the most severely contaminated grain and oil varieties with aflatoxin. Peanut oil raw materials are susceptible to infection by Aspergillus flavus during storage and transportation. If the oil is processed and pressed at home or in a small workshop without detoxification treatment, the content of aflatoxin B1 in the oil often exceeds the standard. Especially in newly squeezed peanut oil in southern regions, the content of aflatoxin B1 is often high, far exceeding that of domestic edible oil (<20 μ G/kg or export trade (<5 μ G/kg standard.

How to remove aflatoxin B1 in industrial production?

Physical methods

Including adsorption method and irradiation method. The adsorption method involves adding activated clay, activated carbon, diatomaceous earth, etc. as adsorbents to peanut oil. These adsorbents not only remove pigments from the crude oil, but also adsorb aflatoxin from peanut oil, greatly reducing the toxin content. Peanut oil treated with activated clay can reduce aflatoxin B1 from 100_g/kg to below 10_g/kg. The commonly used irradiation method is ultraviolet light irradiation. Peanut oil enters the Aspergillus flavus degradation machine before bottling (canning) to reduce or eliminate its toxicity.

Chemical method

Chemical reagents are often used for treatment, such as sodium hydroxide, hydrogen peroxide, sodium hypochlorite, ozone, ammonium salts, and chlorine gas. The commonly used method is to add sodium hydroxide for detoxification through alkaline refining (a step in oil refining). Adding sodium hydroxide to crude oil will cause the toxin to react with the alkali. This can destroy most toxins and lower the aflatoxin content in the oil to below the allowable standard.

Biological methods

It is an ideal method to detoxify peanut oil by utilizing the specificity of enzyme action to specifically decompose aflatoxin without affecting other components of the oil. However, the safety of this method in toxicology requires further experiments on the detoxification mechanism of aflatoxin during degradation, as well as the structure and toxicity of metabolites.

Self extracted rapeseed oil also contains toxic substances

In addition to peanut oil, other self pressed or earth pressed edible oils also pose certain safety risks, such as rapeseed oil. Rapeseed oil is a high erucic acid oil, which can easily lead to cardiovascular disease. During the oil production process, crude rapeseed oil undergoes hydrolysis of glucosinolates by myrosinase, forming some sulfur-containing compounds and other toxic components. No household method can guarantee the complete removal of these substances. So, after scientific processing and refining, the edible oil refined from advanced processes such as degumming, deacidification, and deodorization of crude oil is healthier and more nutritious for consumers.