Measurement of fructose-asparagine concentrations in human and animal foods.

The food-borne bacterial pathogen, Salmonella enterica, can utilize fructose–asparagine (F–Asn) as its sole carbon and nitrogen source. F–Asn is the product of an Amadori rearrangement following the nonenzymatic condensation of glucose and asparagine. Heating converts F–Asn via complex Maillard reactions to a variety of molecules that contribute to the color, taste, and aroma of heated foods. Among these end derivatives is acrylamide, which is present in some foods, especially in fried potatoes. The F–Asn utilization pathway in Salmonella, specifically FraB, is a potential drug target because inhibition of this enzyme would lead to intoxication of Salmonella in the presence of F–Asn. However, F–Asn would need to be packaged with the FraB inhibitor or available in human foods. To determine if there are foods that have sufficient F–Asn, we measured F–Asn concentrations in a variety of human and animal foods. The 400 pmol/mg F–Asn found in mouse chow is sufficient to intoxicate a Salmonella fraB mutant in mo...