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Conheça o significado de alguns termos técnicos encontrados no site:

• Aflatoxins
• Colostrum
• Immunoglobulins
• Inositol
• Nucleotides
• Intestinal Villus and the Micro-Villus

Aflatoxins
According to Heathcote (1984), aflatoxins are secondary toxic metabolites, produced by some lineage of Aspergillus flavus and A. parasiticus, besides other species like A. nomius (Frisvad and Thrane, 1996). Under favourable conditions of temperature and moisture, these funguses can grow in certain foods, which gives rise to the production of aflatoxins (Fortnum, 1986; Lillehoj, 1986).

The main aflatoxins produced by the funguses are B1, B2, G1, and G2. Regarding the toxic effects of the aflatoxins, it was verified that four main aflatoxins present the following degree of toxicity: B1> G1> B2> G2. The most toxic and carcinogenic of these is B1 (Carnaghan et al., 1963).

In the whole world, there is a growing consciousness of the serious consequences that the ingestion of high concentrations of aflatoxins can cause to the health of human beings and animals (FAO, 1993) and even the low concentrations, if taken continuously.
The exposure to the chronic concentrations is more probable than to the more serious concentrations and there is evidence that suggests that the consumption of chronic concentrations of aflatoxins may cause cancer. Therefore, the exposure to chronic concentrations of these toxins represents serious problems for the public health (Roebuch and Maxuilenko, 1994).

The effects of the aflatoxins can be biochemical and biological. Biochemically, the aflatoxins can affect the metabolism of energy, carbohydrates, lipids, and also of nucleic acids and proteins. The biological effects are carcinogenicity, mutagenicity, teratogenicity, hepatotoxicity and aflatoxicoses (Ellis et al., 1991; Bradburn and Coker, 1993).

The economical impact that results from the contamination by aflatoxin takes place in all the stages of the vegetable and animal production, marketing and use of the products (Kubena et al., 1990). The easiness and frequency with which the aflatoxins contaminate the agricultural goods, and at the same time, the exposure of animals to chronic levels of these chemical compounds, through the contaminated diet, can be the main differences between profit and loss for the agro-industrial activity (Jones et al., 1982; Nichols, 1983; Hamilton, 1984).

In many countries, the allowed levels of aflatoxins in foods are located between 5 to 50 ?g.kg-1 (FAO, 1993). In Brazil, the presence of aflatoxins in food is regulated by the Resolution Nº 34.176 of the Ministry of Health (Brazil, 1977), which establishes 30 ?g.kg-1 for the sum of the aflatoxins B1 and G1, and more recently, by the internationalisation of the standards of the “Mercosul”, by the governmental decree Nº 183 of 21st March 1996, of the Ministry of Agriculture, Supply and Land reform, which establishes the very limit of 20 ?g.kg-1, for the sum of the aflatoxins B1, B2, G1, and G2 (Brazil, 1996).

Colostrum
The clostrum is the first product produced by the mammary gland in the beginning of lactation; it is a rich source of antibodies (immunoglobulins) which were produced in the two last months of gestation. It is also a very nourishing food item and it has a laxative effect helping to expel the Meconium.

Immunoglobulins
The immunoglobulins or antibodies are a group of Glycoproteins present in the serum and in the organic liquids, which attack the organism invading agents (antigens). They are produced by the lymphocytes B, precursors that, after being touched, i.e. after having got in touch with the antigen, create the plasmocits of different lineage and cellular clones, which will produce the five fractions of immunoglobulin, called immunoglobulin G, A, M, D and E. In spite of presenting many similarities, they differ in the size, in the aminoacids composition, in the content of carbohydrates and in the electric charge.

The basic structure of a molecule of immunoglobulin (monomer) consists of two chains of polypeptides of light chains and two heavy chains, always in identical pairs. The four chains are held together by disulphide bonds, and the light ones (L) are smaller and common to all classes of immunoglobulin. The heavy chains (H) have a high molecular weight, they contain around 440 aminoacids and are bigger, with different structures in each class or subclass.

The immunoglobulins have two identical places of linkage to the antigen. One is performed by the H chain and the other one by the L chain. They are bifunctional as each immunoglobulin molecule presents a region that acts in the connection with the antigen, while the other one promotes the linkage of the immunoglobulins to the cells of the immune system and to the complement system.

Inositol
The inositol is a cyclic polyalcohol containing a ring of six atoms of carbon and six groups OH, and it is an important cellular constituent, being involved in different biochemical processes. In mammals, the inositol exists mainly in the form of phosphor derivatives, which participate of the cellular communication.

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Nucleotides
The slow degradation of nucleic acids gives rise to a mixture of acids known as nucleotides, always formed by a purinic or pyrimidinic base, a phosphate unit and a pentose unit.

Intestinal Villus and the Micro-Villus
The ‘intestinal villus’ and the ‘micro-villus’ have the function of increasing the absorption of nutrients after digestion.