Pet Food Safety
On March 5, 2014

Measuring up mycotoxin risks in petfood

Technology innovators staying on top of industry needs

The companion animal diet presents a unique and well-documented set of risks to our beloved best friends. Mycotoxins are secondary metabolites synthesized by fungal molds as signature chemicals and "calling cards" deposited into cereals and other crop commodities. A relatively narrow range of fungi produces hundreds of mycotoxins, each with its own unique chemistry and corresponding impact on animal physiology and health.

Mycotoxins are highly stable and resistant to extreme physical conditions including ultra-high temperatures and rapid drying regimes used in commodity processing and the manufacture of petfood. The toxic effects of mycotoxins include: nephrotoxicity, hepatotoxicity, estrogenic imbalance, reproductive disorders, immunosuppression, genotoxicity and carcinogenicity.

Identifying mycotoxin-producing fungi  is the relatively easy part, because no more than half a dozen genera are responsible for mycotoxin production-including Aspergillus and Penicillium (blue/green molds), Fusarium and Claviceps (see Table 1). Pinning down the culprit chemicals we call mycotoxins is much less easy. Hundreds of mycotoxins exist, each with its own unique chemistry and signature syndrome for companion animals, livestock and humans.

Researchers continue to obtain data showing the occurrence and impact of mycotoxins that appear in most cereal grain commodities which are common ingredients in dry petfoods. Aflatoxins have received more attention than any other group of mycotoxins, due to their acute toxicity with high mortality, alongside liver damage and carcinogenicity. Aflatoxin is known to cause loss of appetite, listlessness and vomiting in both dogs and cats.

Mycotoxins are intrinsically stealthy  in both presence and action. Synergistic effects occur when different mycotoxins occur at the same time in raw materials and manufactured food or feed. The consequence of chemical and biological interaction between two or more mycotoxins invariably outweighs the additive effects of the individual chemicals. The use of one mycotoxin as a marker to flag the probable presence of another is the logical move.

"Masked" mycotoxins mean hidden challenges for petfood manufacturers-even though analysis may signal the all clear. These mycotoxins have been modified by chemical reaction and become bound to various natural ingredients in raw materials such as glycosides, glucuronides, esters of fatty acids and specific proteins. These mycotoxins, while not yet chemically active, may not be picked up during analysis. They may then be released by the natural digestive process of the companion animal that consumes them and suddenly become toxic.

One strategy for mitigating the masked mycotoxin problem is to test as far up the raw materials stream as possible. This means looking closely at harvested grain before it goes into storage or processing and ensuring the correct storage and transit conditions are met from farm to finished product manufacturing.

Once present, mycotoxins are  virtually impossible to remove or destroy. Monitoring for prevention and avoidance are key. Mycotoxin management essentially comes down to use of high-efficacy testing technology and equipment.

Having the right testing equipment is the first step towards effective management and control. However, uncertainties around test results may be caused by the heterogeneous distribution of mycotoxins in raw materials and finished food products due to so-called "hot spots." These correspond to damp areas and other pockets compromised by physical and insect damage or contamination, all of which can encourage mold growth and mycotoxin accumulation in a wide range of materials.

Experienced operators are able to assess high-risk commodities and storage areas, and implement mycotoxin testing. Exactly where and when to test for mycotoxins is the subject of detailed study while modern regulatory efforts point to formalized Hazard Analysis and Critical Control Point (HACCP) to encourage thorough understanding and response to potential threats. The FSMA (Food Safety Modernization Act) proposed rule to establish "Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for Food for Animals" formalizes the requirements, although risk analysis and prevention have long been hallmarks of petfood quality and safety efforts worldwide.

Testing technology is currently  evolving along two dimensions within the petfood industry: Laboratory-based technology is expanding in scope, sensitivity and throughput; and portable, on-site testing equipment is becoming smaller, simpler and more economical.

Laboratory-based mycotoxin testing is designed for operation by trained scientists and provides the foundational performance to develop and support industry standards. LC and LC with tandem mass spectrometry (LC/MS/MS) are widely used throughout laboratory and governmental testing sites. They are highly sensitive, precise and able to discern single and multiple mycotoxins with great accuracy and speed.

Rapid methods provide greater flexibility and come in a number of shapes, sizes and levels of complexity. Well-known technologies such as enzyme-linked immunosorbent assay (ELISA) and fluorometer with immunoaffinity (IA) columns are widely used by laboratory and government mycotoxin testing sites, as well as inbound raw materials testing. But while rapid testing has been in place for some time, processing facilities are beginning to benefit from a new generation of on-site test methods that improve speed, use fewer consumable supplies and reagents while minimizing disposal costs.

The new generation of lateral flow strip test technology has risen to the challenge by providing rapid test results with similar accuracy compared to traditional methods and with a comparatively small investment to get started. Lateral flow strip tests bring a new level of productivity to on-site mycotoxin measurement from farm gate to packaged petfood products. Rapid withdrawal of mycotoxin-contaminated consignments or batches at points along the petfood chain help to avoid large-scale contamination that could threaten finished product quality and put companion animals at risk.

Future refinement of lateral flow strip technology promises even broader application for mycotoxins and other important contaminants posing risks to the petfood industry. As we move into a time of unprecedented quality oversight, rest assured that technology innovators are moving quickly to deliver the right solutions to keep the petfood industry thriving in the midst of regulation and change.

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