Procedures to Reduce the Presence of Mycotoxins

The control of mycotoxins should be focused within a program that is usually called “Integrated Control”. This supposes apply some preventive measures at all stages of food production in question. The controls and measures to be implemented should become extended to the following steps:

•• Growing food

•• Selection of varieties

•• Control of insects and pests

•• Fertilization

•• Rotation of crops

•• Period of harvest:

•• Procedure for collection

•• Clean

•• Drying

•• Storage, transport and distribution

•• Pest Control

•• Moisture Control

•• Climate control

•• Cleaning of premises

The measures to be applied will vary depending on whether you want to control mycotoxin. Regarding industrial treatments of foods contaminated with mycotoxins, these may be:

PHYSICAL METHODS OF ELIMINATION

A.1. - CLEANING AND SEPARATION

It is clear that seed fractions are more contaminated. It may apply to manual methods, methods of separation ad flotation separation by density, for example, corn or peanut. In fact, in the case of peanuts, 95% of aflatoxins are located in the seeds that float. In corn, seed routes contain more than the entire mycotoxins. The drawback is that these methods do not allow the complete separation of fractions contaminated.

A.2. - WET GRINDING

Is known that aflatoxin B1 and zearalenone during grinding concentrated in washing water and fiber. To a lesser extent the germ and gluten. However, the resultant starch is substantially free of aflatoxins. Therefore, it is an interesting procedure for the starch obtained, but not for both “byproducts” used in animal nutrition, in which the contrary, mycotoxins suffer a process of concentration.

A.3. - DRY MILLING

In the case of rice, 95% of aflatoxins is safe. In most wheat also found in peripheral areas. In corn, aflatoxin is primarily in seed and in the foliage, but not in the case of zearalenone, which may be found in all fractions. Hence the interest in separation dried, and in the case of certain matches contaminated, particularly by aflatoxins.

B) PHYSICAL METHODS OF DETOXIFICATION

B.1. - THERMAL DEACTIVATION

Aflatoxins are very resistant to temperature and thus are not destroyed completely by procedures such as autoclaving, boiling, or other thermal processes. For example, aflatoxin M1 is stable during pasteurization of milk. However, aflatoxins may destroy, for example, frying in oil or dry, as in the case of peanuts. It also seems to be a good option for microwave heating.

The fumonisin concentration decreases when foods are heat treated at temperatures greater than 150ºC, but it may not guarantee complete detoxification. There are also some data on the partial elimination of ochratoxins.

B.2. – IRRADIATION

There is much information about the effect of irradiating food contaminated with radiation and ultraviolet range of the type. Moreover, processes are expensive and there is a reluctance on its application.

ABSORPTION

Aflatoxins absorb very effectively to various materials when they are in aqueous solution have been used activated charcoals and certain aluminosilicates. The latter are used in animal feed efficiently since several studies show that the degree of absorption may be more than 90%. The same is not true of other mycotoxins, for example, zearalenone, for which the mechanism is shown very inefficient.

CHEMICAL DEGRADATION

Treatment with NH₃ has been the subject of numerous studies. It is used in foods as currently in cotton seed and peanuts, particularly against aflatoxin and fumonisin. It is particularly effective if performed at high temperatures and high pressure. There are other physical-chemical treatments used, as appropriate, for example with sodium disulfide against aflatoxin autoclave, using glucose or fructose and heat to inactivate fumonisins.

A usual treatment is carried out based on the alkali and heat the corn, which reduces the level of aflatoxins and fumonisins. This is called “nixtamalization”. Its effectiveness is controversial, and it has been suggested modification by using hydrogen peroxide and sodium bicarbonate. Since it may be said that no treatment alone can totally eliminate the contaminant, the control must be carried out in an integrated manner.

References

Boehm, J. 1995. Occurrence and Noxiousness of Mycotoxins in European Foods. Polish. Journal of Food and Nutrition Sciences. v.4, n.2, p. 3-7.

Bottalico, A. 1999. Mycotoxins in foods with possible human health implication. Part. I–Aflatoxins. Igiene-Moderna, v.111, n.2, p. 133-169.

Diniz, S.P.S.S. Micotoxins; Biochemical Approach. Ed. Albatroz, Rio de Janeiro, 186p. 2015.

Pozzi, C.R.; Correa, B.; Gambale, W.; Paula, C.R.; Chacon-Reche, N.O; Meirelles, M.C.A. 1995. Postharvest and stored corn in Brazil: Mycoflora interaction, abiotic factors and mycotoxin occurrence. Food Additives and Contaminants. v.12, n.3, p. 313-319.

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