Enlarge / Subway Founder Peter Buck (credit: Getty | James Marshall)
Update, March 6: Subway has released the lab reports from both of its independent tests.
Both Maxxam Analytics in Ontario, Canada and Elisa Technologies, Inc. in Florida used enzyme-linked immunosorbent assays (ELISA) designed for food products to quantify soy in the chicken.
ELISA’s are a standard type of assay that generally detect and quantify substances based on binding by an antibody.
In the assay, antibody binding kicks off a detectable chemical reaction, commonly resulting in a color change.
In the case of Elisa Technologies, the lab used an antibody that binds to soy flour proteins and the lab used known concentrations of those soy proteins for comparison to determine the quantity of soy protein in Subway’s chicken samples.
In all samples, Elisa detected 3 parts-per-million or less of soy proteins, which is well below one percent of the chicken. Maxxam detected 5.3 ppm of soy protein in the chicken, which is still well below one percent.
Earlier this week, Ars reported that an investigation by the Canadian Broadcasting Corporation’s Marketplace revealed that Subway chicken may only contain 50 percent chicken, with the rest being mostly soy.
But, in the fallout from the news, food scientists are scratching their heads at the CBC’s testing methods and interpretation.
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