Identifying Mycotoxin Contamination
Table 1. Mycotoxins commonly detected in food and agricultural products.
Produced by naturally occurring soil-borne molds, mycotoxins are highly toxic metabolites found in most field, orchard, and vine-grown crops (see Table 1). Heat stable and persistent, mycotoxins remain on crops after they’ve been harvested, stored, and processed. In fact, the United Nations Food and Agriculture Organization (FAO) has estimated that 25% of the world’s food crops are contaminated with mycotoxins. Recent studies suggest that contamination is more complex and involves the presence of multiple mycotoxins in a single raw material.
Aflatoxins are among the most widely known and highly regulated mycotoxins. Produced by Aspergillus flavus and A. parasiticus molds, aflatoxin B1 is classified as a Group I carcinogen by the International Agency for Research on Cancer (IARC). Additional mycotoxins of food safety importance include fumonisin, ochratoxin A, patulin, ergot alkaloids, alternaria, deoxynivalenol (DON), nivalenol, zearalenone, and the combination of T-2 and HT-2. Each mycotoxin, or family of toxins, carries a unique toxicity profile, and regulatory guidelines are reflective of the intended use for the product. For example, the EU regulatory limit for aflatoxin M1 in milk products is 0.05 parts per billion (ppb); however, milk used to manufacture infant formula must follow a much stricter limit of 0.025 ppb.
The type or level of mycotoxin contamination varies with each crop season; therefore, having a process in place for screening can help identify high-risk raw materials, suppliers, and geographic regions. Severe weather patterns, warm and humid storage conditions, or even late crop planting may contribute to the severity of mycotoxin contamination.
Once a mold begins producing toxin, the contamination may remain highly localized to a very small area within a crop field or in a “hot spot” inside a storage bin. A single grain or nut kernel may constitute 100% of the aflatoxin contamination in each lot or shipment, for example, indicating the need for thorough inspection and careful sampling, especially at harvest.
Table 2. Lateral flow strip tests have come a long way and are highly sensitive, as these data from a 10-minute multi-toxin test procedure show.
In regions where environmental conditions (such as high heat or humidity) are favorable to mold growth, vigilance is key. Routine “upstream” monitoring is common, helping quality managers to identify and reject unsafe raw materials before they are allowed on site for storage or processing. Once mycotoxins enter the processing stream, the risks of cross contamination or further toxin production by the resident mold are always present. Food recalls or litigation due to mycotoxin contamination can be costly; the average recall costs the food industry between $5 and $10 million/incident, including insurance claims, legal representation, brand, and immediate and long-term business losses. The upstream detection of mycotoxins in raw materials also enables food manufacturers to find alternative markets for an ingredient that may not be suitable for their application but may be just fine for animal feed formulation.
Advancing Mycotoxin Testing Technologies
The Food Safety Modernization Act (FSMA) generated an upsurge in the use of rapid testing technologies. FSMA’s focus on prevention has enabled more food companies to better understand where mycotoxins come from and to manage the mycotoxin contamination of raw materials before they reach the processing facility. Early detection, combined with the unique challenges of our shifting workforce, creates the need for technologies that are simple enough to be used by staff with or without technical training or expertise. Adopting simpler test procedures that don’t require organic solvents and that are helped by automated data management are key factors that improve productivity, worker satisfaction, and safety, while giving the food manufacturer a leg up in meeting their own sustainability objectives.
Traditional mycotoxin testing methods are showing their age for a number of basic reasons. Some call for organic solvents, such as methanol, to extract toxins for analysis, which is what makes water-based test methods very attractive. Other methods, like ELISA, rely on employees handling the actual toxins and hand pipetting prior to sample analysis, risking exposure. Proper storage and disposal of unused testing supplies is also a consideration.
Fewer steps reduce error, bringing greater accuracy and better overall performance to screening tests.
As we know, not all mycotoxin testing takes place in the field. Sometimes it’s necessary to send samples for confirmatory testing to an analytical laboratory where trained lab technicians test for mycotoxins on analytical instrumentation including high performance liquid chromatography (HPLC), ultraperformance liquid chromatography (UPLC) and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). These techniques can be automated to detect and quantify as many as one hundred mycotoxins in a single run. Effective onboarding and retention of new laboratory staff members may require investing in up-to-date instruments or methods, exploring service plans, or upgrading data handling software. Investments like these create an environment where employees are encouraged to learn, grow, work, and hopefully build a career.
Building for the future is always a good plan. There is an incredible opportunity amid the Great Resignation to pause and take a closer look at the technologies we use for food safety testing, and how they impact the employee experience. When our teams and the testing technologies they depend on work well together, food safety testing can deliver the most value.
Jackson is VICAM market development manager for Waters Corporation. Reach her at [email protected].
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