Grains aflatoxins

The aflatoxins are rather unpleasant fungal toxins. At high levels they can cause severe liver damage in animals and humans, and at lower levels they are implicated in liver cancer. These toxins are produced by the fungus Aspergillus flavus, a common contaminant on nuts and grains. Aflatoxin Bi is the most commonly encountered... 

Foods high ia sucrose, proteia, or starch (qv) tend to biad water less firmly and must be dried to a low moisture content to obtain microbial StabiHty. For example, grain and wheat flour can support mold growth at moisture contents above 15% (wet basis) and thus are stored at moisture contents below 14%. Stored grains and oil seeds must be kept at a water activity below 0.65 because certain molds can release aflatoxias as they grow. Aflatoxins are potent carciaogens (see Food toxicants, naturally occurring). 

De Campos, M., Santos, J. C., Olszyna-Marzys, A.,K., Aflatoxin contamination in grains from the Pacific Coast in Guatamala and the effect of storage upon contamination, Bull. Environ. Contam. Toxicol., 24, 789, 1980. (CA93 89863z)... 

It is of interest to compare the shapes and sizes of various molecules with appreciable carcinogenic activity. For example, aflatoxin B] (VI), found in moldy peanuts and grain, is one of the most powerful carcinogens known. Its crystal structure was determined by van Soest and Peerdeman (46-48). 

United States Department of Agriculture Grain Inspection, Packers and Stockyards Administration. Aflatoxin Handbook. Washington, DC Government Printing Office, 2005. 

Charmley, L.L. and Prelusky, D.B., Decontamination of Fusarium mycotoxins, in Miller, J.D. and Tremholm, H.L., eds.. Grain - compounds Other Than Aflatoxin Mycotoxins, Eagan Press, St. Paul, 1994. 

Liver cancer Fungus that grows on peanuts, walnuts, etc. Aflatoxins - produced by fungus in poorly stored grain... 

Aflatoxins Contaminant (mycotoxin) Produced by Aspergillus flavus, especially grains, corn, and peanuts carcinogenic and hepatotoxic... 

Figure 12.11—Comparison of UV andfluorescence detection after chromatographic separation. Aflatoxins, which are carcinogenic contaminants present in certain batches of grain cereals, are controlled by HPLC analysis. It can be seen that the peak intensities in UV detection vary with concentration whereas fluorescence detection is much more sensitive to aflatoxin G2 and B2. (Reproduced by permission of SUPELCO.)...

The uneven distribution of mycotoxins in grain has so far been statistically defined only for aflatoxins in a few matrices (corn, cottonseed, peanuts) (15,16), and sampling plans have been developed worldwide almost entirely for these toxins. 

Studies towards the development of a sensor array for detecting mycotoxins in grain have been described [202] an immunosensor for aflatoxin Bi (AFBi) (VIII) is described as the first example sensor of this array. The sensor is based on an SPCE bearing surface-absorbed... 

J.D. Miller and H.L. Trenholm, Mycotoxins in Grain. Compounds Other than Aflatoxin, Eagan press, St. Paul, USA, 1994. 

Aflatoxins are products of species of the genus Aspergillus, particularly A flavus, a common fungus found as a contaminant of grain, maize, peanuts, and so on. First implicated in poultry diseases such as Turkey-X disease, they were subsequently shown to cause cancer in experimental animals and, from epidemiological studies, in humans. Aflatoxin Bl, the most toxic of the aflatoxins, must be activated enzymatically to exert its carcinogenic effect. 

The most common source of aflatoxins is moldy food, particularly nuts, some cereal grains, and oil seeds. The most notorious of the aflatoxins is aflatoxin B1( for which the structural formula is shown in Figure 19.1. Produced by Aspergillus niger, it is a potent liver toxin and liver carcinogen in some species. It is metabolized in the liver to an epoxide (see Section 7.3). The product is electrophilic with a strong tendency to bond covalently to protein, DNA, and RNA. Other common aflatoxins produced by molds are those designated by the letters B2, G1( G2, and M,. 

FIGURE 5-46. Separation of aflatoxins. This method was used to evaluate peanut butter and intended for use with other grain products. Column /uPorasil (silica, 10 jam), 3.9 mm ID x 30 cm. Mobile phase CHC13 (H20 Sat)/C6H12/CH3CN, 25 7.5 1 (v/v). Flow rate 1.0 mL/min. Detector UV 365 nm, 0.005 AUFS. Structures are shown on top of figure. (Method described in reference 27.)... 

Inspects grain, rice, and related products for quality and aflatoxin contamination. 

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