Worldwide stable carbon and nitrogen isotopes of Big Mac® patties: An example of a truly glocal food

The Big Mac (R), McDonald's (R) signature burger, is a global food served in over 100 countries. We measured carbon (delta C-13) and nitrogen (delta N-15) stable isotope ratios of Big Macs (R) from twenty-six countries. The delta C-13 values varied from -25.4%. to -11.1%, representing cattle-rearing systems based exclusively on C-3 plants, exclusively on C-4 plants, or both C-3 and C-4 plants. Median (delta N-15 value was 6.6 parts per thousand; the 25th and 75th percentile were 5.9 parts per thousand and 7.3 parts per thousand, respectively. Calculated percentages of imported beef were consistent with the delta C-13 values of purchased Big Macs (R). Japanese patties had higher delta C-13 values than expected based on that country's C-3 agriculture, however Japan imports beef from Australia, where C-4 plants are prevalent. Lower latitude countries generally had higher delta C-13 values than higher latitude countries, reflecting the larger distribution of C-4 plants in warm regions. Although Big Macs (R) are a global food, we conclude they also contain local components. (C) 2011 Elsevier Ltd. All rights reserved.