205
group, but only the aflatoxins B1, B2, G1, G2, and MI are routinely monitored in
foods and feeds in commerce.
Monitoring foods for the presence of aflatoxins is important to ensure consumer
safety. During the past two decades, several chromatographic methods have been
developed for the quantification of aflatoxins in agricultural and food products.
Traditionally aflatoxin analysis has been performed using solvent extraction, followed by sample cleanup by solid-phase extraction (SPE) for purification prior to
analysis. The immunoaffinity technique enables a wide variety of food matrices to
be analyzed using a one-step extraction protocol without the need to use halogenated hydrocarbon solvents for extraction (Otta et al. 2000).
12.9.1 Definition of Aflatoxins
Aflatoxins, difuranocoumarin compounds, are toxic secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus. They were isolated and
characterized after the death of more than 100,000 turkey poults (turkey X disease)
was traced to the consumption of mold-contaminated peanut meal. Thereafter, aflatoxins were found to contaminate a wide variety of agricultural products, including
corn, rice, wheat, spices, and nuts (Nonaka et al. 2009).
12.9.2 Factors Promoting Fungal Growth
and Aflatoxin Production
These factors could be extrinsic (temperature; relative humidity; soil properties;
mechanic injury on food commodity; insect and rodent attack) or intrinsic (pH,
nutrient composition, moisture content/water activity). These factors, however, do
not work in isolation. Therefore, two or more factors may have to be met before
fungal growth and corresponding toxin production can be effected.
12.9.2.1 Temperature
It has been reported that whether there is high or low temperature, fungal growth
and its resultant mycotoxin production are inevitable. Atanda et al. observed that
temperatures below 20 °C favored Penicillium and Cladosporium whereas above
20 °C enhanced growth of Aspergillus species. The researchers also reported that
food products such as cereals and legumes were more prone to Aspergillus species
than any other toxin-producing fungi, more so at storage due to the temperatures
involved. However, fungal activity and toxin production have been reported
12 Fungal Mycotoxins
group, but only the aflatoxins B1, B2, G1, G2, and MI are routinely monitored in
foods and feeds in commerce.
Monitoring foods for the presence of aflatoxins is important to ensure consumer
safety. During the past two decades, several chromatographic methods have been
developed for the quantification of aflatoxins in agricultural and food products.
Traditionally aflatoxin analysis has been performed using solvent extraction, followed by sample cleanup by solid-phase extraction (SPE) for purification prior to
analysis. The immunoaffinity technique enables a wide variety of food matrices to
be analyzed using a one-step extraction protocol without the need to use halogenated hydrocarbon solvents for extraction (Otta et al. 2000).
12.9.1 Definition of Aflatoxins
Aflatoxins, difuranocoumarin compounds, are toxic secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus. They were isolated and
characterized after the death of more than 100,000 turkey poults (turkey X disease)
was traced to the consumption of mold-contaminated peanut meal. Thereafter, aflatoxins were found to contaminate a wide variety of agricultural products, including
corn, rice, wheat, spices, and nuts (Nonaka et al. 2009).
12.9.2 Factors Promoting Fungal Growth
and Aflatoxin Production
These factors could be extrinsic (temperature; relative humidity; soil properties;
mechanic injury on food commodity; insect and rodent attack) or intrinsic (pH,
nutrient composition, moisture content/water activity). These factors, however, do
not work in isolation. Therefore, two or more factors may have to be met before
fungal growth and corresponding toxin production can be effected.
12.9.2.1 Temperature
It has been reported that whether there is high or low temperature, fungal growth
and its resultant mycotoxin production are inevitable. Atanda et al. observed that
temperatures below 20 °C favored Penicillium and Cladosporium whereas above
20 °C enhanced growth of Aspergillus species. The researchers also reported that
food products such as cereals and legumes were more prone to Aspergillus species
than any other toxin-producing fungi, more so at storage due to the temperatures
involved. However, fungal activity and toxin production have been reported
12 Fungal Mycotoxins