Matrix‐Assisted Laser Desorption/Ionization Time‐of‐Flight Mass Spectrometry (MALDI‐TOF MS) of Proanthocyanidins to Determine Authenticity of Functional Foods and Dietary Supplements

The lack of analytical methods to determine authenticity of proanthocyanidins (PAC) in functional foods and dietary supplements is a problem in market regulation and development of efficacious products. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) of PAC structure offers good potential for rapid analysis in authenticity research. We used MALDI-TOF MS and deconvolution to determine the percentage of A- and B-type interflavan bonds in PAC oligomers. Deconvolution works because isotope patterns are repeatable and accurate. Multivariate analysis using relative ratios of A- to B- type interflavan bonds as determined by deconvolution or autoscaled spectra was used to classify and differentiate plant species based on PAC spectral data. Principal component analysis (PCA) of PAC spectra data was able to differentiate botanical sources and linear discriminant analysis (LDA) correctly classified botanical sources, indicating that MALDI-TOF MS combined with multivariate analysis is an effective tool to determine PAC authenticity.