Now, more than ever, food manufacturers are looking to lab science for safe and speedy answers, especially when it comes to allergens. Food allergies are a public health liability that affects both business and the consumer. More than 12 million Americans have food allergies, and many more are underdiagnosed or ignored.
Explore this issueDecember/January 2012
In fact, eight major allergens—fish, shellfish, peanuts, tree nuts, wheat, soy, egg, and dairy—designated by the Food Allergen Labeling and Consumer Protection Act (FALCPA) are responsible for more than 90% of all allergic reactions in the world.
Cross-contamination incidents, such as the Salmonella scare that caused the egg recall of 2010, are on the rise as well, and have renewed consumers’ unease with—and often distrust of—labels. As a result of this spike, manufacturers are feeling greater pressure to provide safe products, resulting in demands for more expedient testing results from quality assurance labs.
Although food lab scientists have myriad processes and technologies for food safety and quality assurance at their fingertips, the greatest improvements are being made to the systems already leading the industry: ELISA and PCR. When it comes to determining which of the two is better, or ideal, for integration, consider it on a case-by-case basis. Integrate one of these microtechnologies into your hazard analysis and critical control points program to increase testing turnaround and meet manufacturers’ deadlines, whether you are faced with allergens or bacteria.
The enzyme-linked immunosorbent assay ELISA kit is a molecular biology industry standard—a rapid immunochemical test that uses components of the immune system and chemicals to detect potential allergic reactions in the body. Traditional food allergen detection uses ELISA to find protein. This common practice, which uses antibodies to detect antigens, is applied through the preparation of monoclonal antibodies, which detects their presence through the confirmation of an allergen. Every allergen has a specific protein that makes it unique, one that can cause a negative physical reaction when the body doesn’t recognize it.
Very often, ELISA can detect food allergens, although cross reactivity may occur and diminish the certainty of results. These kits are easy to operate and are generally low cost: between $2 to $11 per test. Because the ELISA is protein-based, it is proficient at determining the exact source of an allergen, such as dairy or wheat. Before the ELISA, the only option for conducting similar testing was with radioimmunoassay—a technique that uses radioactively labeled antibodies and requires expensive radioisotopes or counters. ELISA’s biggest benefit is the elimination of radioactive substances; the method is leading the way in lab innovation technology.
The ABCs of PCR
Polymerase chain reaction (PCR), another lab science favorite, analyzes even the smallest components of DNA through a screening process that takes mere days and provides nearly guaranteed accuracy.
It involves a simple two-part process: first, sample preparation and amplification, then detection. In the PCR process, screening is the noteworthy advancement in technology—previously, amplification of DNA involved cloning and plating bacteria, then a three-day incubation period followed by a manual count of the cells. Results were not available for weeks. Although it is a considerable expense up front at an average of $30,000, a PCR system, such as the automated BAX for screening Salmonella, requires less time, fewer personnel, and fewer chemicals—essentially paying for itself over time. Currently, members of the Association of Official Analytical Chemists have exclusive rights to access this procedure.
Although food lab scientists have myriad processes and technologies for food safety and quality assurance at their fingertips, the greatest improvements are being made to the systems already leading the industry: ELISA and PCR.
Additional advancements in PCR methods have noticeably improved avenues for analyzing DNA sequences, as well as the characterization of messenger RNA. Specifically within RNA detection, reverse transcription-PCR (RT-PCR) is the most sensitive technique on the market, enabling reproduction of RNA from just one cell. RT-PCR provides higher sensitivity and specificity than the traditional immunological testing and is another option for even more sensitive results. Most recently, PCR advancements have been made involving the use of a DNA chip to identify mycoplasma, bacteria, or viruses in biopharmaceutical research and production using specific genetic fingerprints. Overall, the greatest impacts PCR has on the industry are its DNA-based results accuracy and its ability to detect minute bacteria.
Food manufacturers and processors must also rely on accurate, affordable testing to identify allergen risks. Food allergen detection tests are available to give companies the proof of performance they need. Among several different available methods, the allergy swab is a versatile option, because it detects the eight major allergens listed by the FALCPA; some swabs can even detect coconut, mustard, coffee, and red wine.