Reduction of risks associated with fumonisin contamination in corn

Biological detoxification of fumonisin by a novel carboxylesterase from Sphingomonadales bacterium and its biochemical characterization

Fumonisins have posed hazardous threat to human and animal health worldwide. Enzymatic degradation is a desirable detoxification approach but is severely hindered by serious shortage of detoxification enzymes. After mining enzymes by bioinformatics analysis, a novel carboxylesterase FumDSB from Sphingomonadales bacterium was expressed in Escherichia coli, and confirmed to catalyze fumonisin B1 to produce hydrolyzed fumonisin B1 by liquid chromatography mass spectrometry for the first time. FumDSB showed high sequence novelty, sharing only ~34% sequence identity with three reported fumonisin detoxification carboxylesterases. Besides, FumDSB displayed its high degrading activity at 30-40 °C within a broad pH range from 6.0 to 9.0, which is perfectly suitable to be used in animal physiological condition. It also exhibited excellent pH stability and moderate thermostability. This study provides a FB1 detoxification carboxylesterase which could be further used as a potential food and feed additive.

Impact of food processing and detoxification treatments on mycotoxin contamination

Mycotoxins are fungal metabolites commonly occurring in food, which pose a health risk to the consumer. Maximum levels for major mycotoxins allowed in food have been established worldwide. Good agricultural practices, plant disease management, and adequate storage conditions limit mycotoxin levels in the food chain yet do not eliminate mycotoxins completely. Food processing can further reduce mycotoxin levels by physical removal and decontamination by chemical or enzymatic transformation of mycotoxins into less toxic products. Physical removal of mycotoxins is very efficient: manual sorting of grains, nuts, and fruits by farmers as well as automatic sorting by the industry significantly lowers the mean mycotoxin content. Further processing such as milling, steeping, and extrusion can also reduce mycotoxin content. Mycotoxins can be detoxified chemically by reacting with food components and technical aids; these reactions are facilitated by high temperature and alkaline or acidic conditions. Detoxification of mycotoxins can also be achieved enzymatically. Some enzymes able to transform mycotoxins naturally occur in food commodities or are produced during fermentation but more efficient detoxification can be achieved by deliberate introduction of purified enzymes. We recommend integrating evaluation of processing technologies for their impact on mycotoxins into risk management. Processing steps proven to mitigate mycotoxin contamination should be used whenever necessary. Development of detoxification technologies for high-risk commodities should be a priority for research. While physical techniques currently offer the most efficient post-harvest reduction of mycotoxin content in food, biotechnology possesses the largest potential for future developments.

Occurrence, Rapid Analysis, and Detoxification of Fumonisins in Maize and its Feeds: Review

Maize (Zea mays L.) is one of the main cereals as a source of food, forage and processed products for industry, especially for feeds. However, in worldwide approximately 25% of crops are affected by mycotoxins annually, especially in feeds with fumonisins(FUM). Moreover, the exact mechanism of FUM toxicity is not completely established. This paper gives an overview about the occurrence, toxicity, rapid non-invasive analysis, and detoxification of FUM in maize and its feeds. Due to economic losses engendered by FUM and its impact on animal and human health, several strategies for detecting mycotoxins with non-invasive methods and detoxifying contaminated feeds have been described.

Review: HPLC Determination of Fumonisin Mycotoxins

An overview of liquid chromatographic methods, mainly employing fluorescence detection together with sample pre-treatment methods, is presented for the determination of the toxic group of fumonisin mycotoxins in various matrices.

Effect of processing on aflatoxin

Naturally occurring toxicant contamination of foods with mycotoxins is unavoidable and unpredictable and poses a unique challenge to food safety. Aflatoxins are toxic mold metabolites produced by toxigenic strains of Aspergillus species. Primary commodities susceptible to aflatoxin contamination include corn, peanuts and cottonseed and animal-derived foods such as milk when the animal is fed aflatoxin-contaminated feed. Risks associated with aflatoxin-contaminated foods can be reduced through the use of specific processing and decontamination procedures. Factors, which influence the effectiveness of a specific process or procedure, include the chemical stability of the mycotoxin(s), nature of the process, type and interaction with the food/feed matrix and interaction with multiple mycotoxins if present. Practical decontamination procedures must: 1) inactivate, destroy, or remove the toxin, 2) not produce or leave toxic residues in the food/feed, 3) retain the nutritive value of the food/feed, 4) not alter the acceptability or the technological properties of the product, and, if possible, 5) destroy fungal spores. For aflatoxins, multiple processing and/or decontamination schemes have been successful in reducing aflatoxin concentrations to acceptable levels. Physical cleaning and separation procedures, where the mold-damaged kernel/seed/nut is removed from the intact commodity, can result in 40-80% reduction in aflatoxins levels. Processes such as dry and wet milling result in the distribution of aflatoxin residues into less utilized fractions of the commodity. The ammoniation of aflatoxin-contaminated commodities has altered the concentrations as well as toxic and carcinogenic effects of aflatoxin by greater than 99%. Nonbiological materials such as selected anticaking agents covalently bind aflatoxins from aqueous suspensions, diminish aflatoxin uptake by animals, prevent acute aflatoxicosis, and decrease aflatoxin residues in milk. Ultimately, the best processing or decontamination process is one that is approved by regulatory agencies, cost-effective, and reduces the mycotoxin concentration to acceptable levels.

Mycotoxicosis in food producing animals

Mycotoxins are toxic secondary metabolites of fungi. Diseases caused by mycotoxins are collectively referred to as mycotoxicosis. Disease is usually initiated after ingestion of feeds containing toxic doses of mycotoxins. Signs and symptoms vary and depend on the animal, the organ system involved, and on the dose and type of mycotoxins ingested. The symptoms can range from acute death, immunosuppression to skin lesions or to signs of hepatotoxicity, nephrotoxicity, neurotoxicity, or genotoxicity. In addition to concerns over adverse effects of mycotoxins on food animals consuming mycotoxin-contaminated feeds, there is also a public health concern over the potential for human beings to consume animal-derived food products such as meat, milk, or eggs, containing residues of those mycotoxins or their metabolites.