Peanuts are susceptible to Aspergillus flavus, the main factor affecting the quality of peanut oil is Aflatoxin b1. Aflatoxin is a type of hepatotoxicity produced by Aspergillus flavus and Aspergillus parasiticus. It is very toxic. It has a strong effect on humans and animals. At present, there are more than ten kinds of Aflatoxins identified as B1, B2, G1, G2, M1, M2, P1, Q1, etc. Among them, Aflatoxin b1 is highly toxic and pathogenic. It is a strong chemical carcinogen found so far.
The state strictly controls the content of Aflatoxin in grain and oil products. The Aflatoxin content in peanut oil and its products should not exceed 20 micrograms/kg, and the export trade requirement should not exceed 5 micrograms/kg. However, the content of Aflatoxin in freshly squeezed peanut oil is often too high, which does not meet the requirements for domestic consumption or export. Therefore, understanding the method of removing Aflatoxin in peanut oil and controlling the content of Aflatoxin in peanut oil is very important for people health.
At present, the main methods for removing Aflatoxins in peanut oil are: physical methods, chemical methods, biological methods and other methods.
The physical removal methods of Aflatoxin mainly include irradiation and adsorption.
Ultraviolet and gamma radiation can effectively control and kill microorganisms and fungal pathogens. At present, the effectiveness and safety of ultraviolet radiation technology in the removal of Aflatoxin from peanut oil has been confirmed. The application of ultraviolet irradiation technology to remove Aflatoxins in peanut oil not only is effective and safe, but also has no effect on the quality of peanut oil. The best way is using aflatoxin b1 degradation machine, keep peanut oil in original tastes.
The adsorption method is a commonly used method for Aflatoxin detoxification in the current edible oil refining process. Commonly used adsorbents include activated carbon, activated clay, diatomaceous earth, etc. It has been reported that the peanut oil treated with activated clay can reduce Aflatoxin b1 from 100μg/kg to less than 10μg/kg. There have been many researches on new types of adsorbents, such as bio-sorbents, but their application effects remain to be investigated.
Chemical methods are mostly treated with chemical reagents, such as sodium hydroxide, hydrogen peroxide, sodium hypochlorite, ozone, ammonium salts, and chlorine. One of the most commonly used is to add sodium hydroxide to detoxify through alkali refining (alkali refining itself is a method of oil refining). Adding sodium hydroxide to crude oil will cause the toxin to react with alkali to make the internal alicyclic structure of Aflatoxin destroyed and hydrolyzed into water-soluble coumarin sodium salt.
This method can destroy most of the toxins and reduce the Aflatoxin content in the oil to below the allowable standard. However, the inherent fragrance of peanut oil is also removed at the same time, which affects the quality of peanut oil. In addition, a certain amount of antioxidants such as commonly used BHT and BHA can also be added to peanut oil, which can inhibit the carcinogenic effect of Aflatoxin b1.
Aflatoxin can be rapidly hydrolyzed in sodium hydroxide solution to form ortho-coumarin sodium salt, which is soluble in water and can be removed in the washing process after alkali refining. Studies have shown that 1% sodium hydroxide aqueous solution treatment of peanut cake containing Aflatoxin can reduce the toxin from 84.9lμg/kg to 27.6lμg/kg. The test results show that: the effect of alkali refining detoxification method can reach 75%-98%.
It uses the specificity of enzyme action to detoxify peanut oil with enzymes that specifically decompose Aflatoxin but have no effect on other components of the oil. This is an ideal method. However, the safety of this method in toxicology requires further experiments on the detoxification mechanism of Aflatoxin in the degradation process and the structure and toxicity of metabolites.
The biological detoxification of Aflatoxin mainly uses microorganisms or their enzymes and their preparations for detoxification. It has the advantages of high efficiency, strong specificity, no pollution to materials and the environment, relatively mild processing conditions, and no damage to products quality, some of which can increase the nutritional value of the product, representing a new direction of biological detoxification, and receiving extensive attention and research.
Biological methods mainly include the degradation of Aflatoxins by microbial cells, microbial metabolites and their extracts to degrade Aflatoxins. Biological methods for detoxification mostly use enzymatic reactions, showing their great advantages and application prospects.
However, due to the harsh conditions of enzyme action, unstable properties, and easy inactivation, there is still a certain distance from actual production and application. At present, the practical application of biological methods to degrade Aflatoxin at home and abroad has just started. The key to the technology is to screen out strains that can produce high-activity detoxification enzymes, and create a microenvironment that is conducive to enzymatic reactions and maintain the stability of enzyme properties.
How to remove aflatoxin b1 from peanut oil?
In order to ensure that the content of aflatoxin b1 in peanut oil does not exceed the standard, in addition to the above-mentioned methods to remove Aflatoxin in the oil production process, the growth and storage environment of peanuts should also be controlled to reduce Aflatoxin. And peanuts should be strictly selected to further reduce the amount of Aflatoxin carried by the raw peanuts.
The main Aspergillus flavus of Aflatoxin lies in the Aflatoxin it produces. This toxin is relatively stable and has strong heat resistance. It does not crack until 280 degrees. It is stable in an acidic and neutral environment, but can be destroyed in alkaline solution at pH 9~10. It can also be destroyed by ultraviolet radiation.