In this study (open access) the authors developed a chemometric model to discriminate adulterated maple syrup. Spectral measurement was by Attenuated Total Reflectance FTIR with data then processed using Principle Component Analysis. The authors built their reference library from 69 authentic samples obtained directly from producers and further verified by an expert sensory panel. They prepared in-house adulterated samples by mixing in sugars from three of 15 cheaper sources at proportions from 5% to 25% giving a total library of 667 adulterated and non-adulterated reference samples. Spectra from these samples were used to build six libraries and three models. They developed a method to perform a qualitative library search using a similarity search, based on the first derivative correlation search algorithm.
Of the four Canadian classes of Grade A maple syrup, the model could discriminate with high confidence adulteration in “golden” and “amber” syrups but was less specific for “dark” or “very dark” classes.