Mycotoxin Adsorbent Selection Full Points
Mycotoxins are products of the natural metabolism of molds, and more than 500 mycotoxins have been found so far.
A variety of mycotoxins commonly coexist in grains and feeds, and the superposition or synergy between different mycotoxins will greatly enhance the virulence of mycotoxins. Cause mycotoxins to affect the production performance of animals from the aspects of immunity, reproduction, digestion and so on.
At present, there are many types of mycotoxin adsorbents, which can be basically divided into three categories:
First, aluminosilicates, including zeolite, montmorillonite and other clay-based adsorbents, are mainly composed of sodium calcium aluminosilicate hydroxide, and their adsorption effect is closely related to the interlayer structure, surface area, and ionic polarity. The large surface area and electrostatic adsorption force can strongly adsorb mycotoxins with ionic polarity, especially highly polar mycotoxins such as aflatoxins;
Second, organics, such as activated carbon, lignin and yeast cell wall extract - β-glucomannan. Organic adsorbents selectively adsorb low polarity mycotoxins, such as zearalenone, fumagillin, vomitoxin, T2 toxin, etc.
Third, enzymes or biodegradation. Currently, there are reports that lactic acid bacteria, acetic acid bacteria, baker's yeast, Saccharomyces cerevisiae, Aspergillus oryzae and Bacillus subtilis can degrade aflatoxin.
So, how to choose these three types of mycotoxin adsorbents? We may wish to learn more about adsorption and adsorption principles.
Aluminosilicates such as zeolite, montmorillonite, diatomite, kaolin, etc. have a certain selective adsorption capacity for mycotoxins because of their large surface area ratio and ion adsorption capacity.
(1) Absorb aflatoxin, and cannot adsorb various types of mycotoxins present in the feed at the same time;
(2) The effective addition amount is large, which takes up too much formula space;
(3) While adsorbing mycotoxins, it is combined with nutrients such as vitamins and minerals in the feed to interfere with the utilization of nutrients;
(4) May contain dioxins, heavy metals and other pollutants, contaminating feed to a certain extent. 1) Absorbs aflatoxins, and cannot adsorb various types of mycotoxins present in the feed at the same time;
In recent years, a large number of studies have proved that β-glucomannan can effectively adsorb different kinds of mycotoxins, including the most common aflatoxin, T-2 toxin, zearalenone, DON, fumonisin and Ochratoxin, etc.
Research from the University of Missouri in the United States has shown that esterified glucomannan can slow the loss of weight gain in weaned piglets due to DON or zearalenone.
Due to the effective adsorption of mycotoxins by yeast cell wall extracts, the damage of mycotoxins to animal health is reduced, and the deposition of mycotoxins in human edible meat, eggs and milk is also reduced, ensuring the safety of the food chain.
Enzyme or live bacteria adsorbent
At present, the application of biological methods to degrade mycotoxins in feed is very few at home and abroad, and there are mainly the following limiting factors:
1. Live bacteria and enzymes have poor heat tolerance and will be destroyed during the granulation process. Some enzymes do not even work at the body temperature of livestock.
2. Live bacteria and enzymes have poor acid tolerance and may be destroyed by gastric acid when passing through the stomach of livestock. At the same time, the use of organic acids in feed will also inhibit and destroy such products.
3. The specificity of the enzyme to the substrate is very strong. Since there are many types of mycotoxins and their structures are quite different, basically one enzyme species can only decompose one type of mycotoxins.