Application of 2H SNIF-NMR and 13C SIRA-MS Analyses to Maple Syrup: Detection of Added Sugars

The SNIF-NMR method may be used to measure the site specific isotope concentrations in a variety of organic compounds. The most common application of this technique involves quantitative deuterium nuclear magnetic resonance spectroscopy with appropriate interpretation of the accumulated spectra. SNIF-NMR together with SIRA-MS provides a powerful tool for food authentication and characterization. The concerted use of SNIF-NMR (deuterium) and SIRA-MS (carbon-13) on ethanol fermented from sugars has proven invaluable to the authentication of wines, spirits, and fruit juices. In this work, the analysis is extended to the authentication of maple syrup, a product rich in sucrose. Authentic maple syrup samples have been analyzed in detail to characterize the intrinsic variability of the isotopic ratios in this product. These data constitute a data base of authentic samples to which an unknown example of maple syrup can be compared. The isotopic ratios obtained from maple syrup are very different from those of both beet and cane or corn sugars. Therefore, the methodologies developed in this work are applicable for the detection of beet and cane or corn sugar added to a maple syrup. It can be shown that, through a simple statistical comparison between the data base and the unknown, a determination of the occurrence and/or extent of adulteration with added sugar can be made.