Geographical Region-of-Origin Assignment of American Beef Using Stable Isotope Analysis

CHESSON, LESLEY A; VALENZUELA, LUCIANO O; O'GRADY, SHANNON P; CERLING, THURE E; EHLERINGER, JAMES R

Washington

Conferencia; Forensics Isotope Ratio Mass Spectrometry Conference; 2010

Animal diseases like bovine spongiform encephalopathy (BSE) and hoof-and-mouth (HMD) have highlighted the pressing need for food traceability in the modern food market. Stable isotope analysis is a promising analytical technique that may provide region-of-origin information independent of food labels since the stable isotope ratios of hydrogen and oxygen in water vary across landscapes in predictable patterns. Animals like beef cattle record the isotopic composition of local environmental water in their tissues and the analysis of beef meat could therefore be used to assign a geographical origin to the animal.We collected hamburger (beef) patties from fast food restaurants in Salt Lake City, UT. Restaurants were classified as either local those chains found only in Utah or national. We also collected samples of beef from family-run ranches across the USA to calculate an equation for the relationship between beef δ2H and δ18O values and local water δ2H and δ18O values. This equation was used to predict the stable isotope ratios of cow drinking water from the δ2H and δ18O values of hamburgers purchased in Utah restaurants. We found the mean hydrogen and oxygen stable isotope ratios of hamburgers from local restaurants were significantly different from those purchased in national fast food restaurants. Using the predicted cow drinking water δ2H and δ18O values, we were able to calculate the average size of the food footprint (in beef transport miles) for patrons of local and national fast food restaurants in Utah. From this statewide survey, we have demonstrated the promise and potential of food tracking using stable isotope analysis.