Safeguarding the Food Supply
The ARS food safety research program ensures a safe food supply that meets foreign and domestic regulatory requirements. Emerging research areas focus on metagenomics, climate change and mycotoxin contamination, food adulteration and fraud, reducing foodborne pathogens during animal and crop production and food processing, and contamination of ready-to-eat foods. The following accomplishments highlight ARS advances in food safety research in FY 2020.
A novel strategy for estimating Salmonella contamination levels in raw ground beef. Salmonella is a leading cause of foodborne illness worldwide. In spite of the use of numerous process controls in food production industries, there has been little progress in decreasing the occurrence of Salmonella food poisoning over the past decade. This is in part because current testing methods indicate only the presence or absence of Salmonella, but they do not measure how much contamination is in a tested product. To address this need, ARS scientists in Clay Center, NE, developed a novel strategy for rapidly estimating Salmonella contamination levels in raw ground beef based in the same amount of time that it takes to detect Salmonella in enrichments using two different commercial molecular detection methods. The ability to detect high levels of Salmonella contamination will enable meat companies to improve their process controls and remove more highly contaminated products from the food chain. This will improve the safety of beef and decrease the incidence of human exposure to levels of Salmonella that cause disease.
A rapid test for masked toxins in wheat. Trichothecenes are a group of fungal toxins (mycotoxins) that can contaminate oat, wheat, barley, and corn, and cause substantial economic losses worldwide. Trichothecenes are toxic to humans and animals, and upon consumption, the toxin inhibits ribosomal protein, DNA, and RNA synthesis; mitochondrial functions; and cell division while simultaneously activating a cellular stress response. As part of efforts to improve monitoring of these trichothecene toxins, ARS scientists in Peoria, IL, in collaboration with the Institute of Sciences of Food Production in Bari, Italy, developed a new method to detect trichothecenes in wheat. Trichothecenes are also toxic to plants, but plants can protect themselves from the toxins by attaching a sugar residue to a trichothecene molecule, which makes them less toxic. The plant toxin derivatives are called masked mycotoxins, and are difficult to detect. During the human digestion process, the original toxin may be released from the masked state, resulting in mycotoxin poisoning. The new toxin/masked mycotoxin detection method is rapid, sensitive, and convenient and will be used to monitor trichothecenes and their modified forms in wheat. Improved monitoring for the trichothecenes and their masked forms can be used to reduce exposure to these toxins by diverting the contaminated food product from the food supply.
New smartphone-based food safety spectrometer. Industry and regulatory inspectors are required to monitor products for safety as they proceed through the food production and processing continuum. Normally samples are taken and sent to an internal or external laboratory for analysis using various types of assays. A major limitation of many food safety assays is that they require expensive equipment found only in centralized laboratories. Both industry and inspectors would prefer, where possible, that samples obtained in the field be analyzed on site, and data immediately be made available. ARS-funded scientists at the Center for Food Safety Engineering at Purdue University have developed a smartphone-based spectrometer that can resolve the visible range of spectrum in transmission mode and can be used to analyze many types of food safety assays. The overall cost of the spectrometer is only $200 and functions with an app that can visualize, record, and analyze the visible spectrum. The outcome is that this device could be incorporated into many types of assays with visual readouts to allow data to be used at the point the sample is taken, simplifying the food safety assay process, and thus reducing the time required to obtain a result and transfer the data.
Updated method to analyze contaminants in foods.. Analysis of foods for the presence of pesticides, veterinary drugs, and environmental contaminants is necessary for public health. In 2003, ARS developed the QuEChERS approach to sample analyze pesticide residues in foods. This method has now become the primary and gold standard used worldwide in chemical residue analysis. Instrumentation and technology have continued to improve in the past 17 years, creating a need to update the QuEChERS method. Consequently, ARS scientists in Wyndmoor, PA, have now developed and validated the “quick, easy, cheap, effective, rugged, safe, efficient, and robust” (QuEChERSER) mega-method using mass spectrometry to analyze pesticides, veterinary drugs, and environmental contaminants in foods. So far, the new QuEChERSER mega-method has been validated for up to 349 diverse analytes in fish, bovine, caprine, and ovine muscle; hemp products; and fruits and vegetables. Once implemented internationally, QuEChERSER is expected to eventually supplant QuEChERS as the primary method for monitoring a wide array of chemical contaminants in foods.