Classification of proanthocyanidin profiles using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) spectra data combined with multivariate analysis

• Published in: Food chemistry 2021-01, Vol.336, p.127667-127667, Article 127667
• Main Authors: Esquivel-Alvarado, Daniel, Alfaro-Viquez, Emilia, Krueger, Christian G., Vestling, Martha M., Reed, Jess D.
• Format: Article
• Language: English
• Subjects: A-type interflavan bonds; Adulteration; Apples; B-type interflavan bonds; Cranberry; Deconvolution of overlapping isotope patterns; Linear discriminant analysis; Peanut skins; Principal component analysis
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.127667

•Proanthocyanidin profiles of apples, cranberries, and peanut skins were characterized by mass spectrometry.•Percentage of A- to B-type interflavan bonds varied amongst proanthocyanidin sources.•Principal component analysis was used to differentiate amongst proanthocyanidin sources.•Linear discriminant analysis was used to discriminate amongst proanthocyanidin sources. Proanthocyanidin (PAC) profiles of apples (a-PAC), cranberries (c-PAC), and peanut skins (p-PAC) were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Deconvolution of overlapping isotopic patterns indicated that in apples, only 5% of the PAC oligomers contain one or more A-type bonds, whereas in cranberries and peanut skins, 96% of the PAC oligomers contain one or more A-type bonds. MALDI-TOF MS data combined with multivariate analysis, such as principal component analysis (PCA) and linear discriminant analysis (LDA), were used to differentiate and discriminate a-PAC, c-PAC, and p-PAC from one another. Mixtures of c-PAC with either a-PAC or p-PAC at different w/w ratios were evaluated by LDA modeling. The LDA model classified the training, testing, and validation sets with 99.4%, 100%, and 94.2% accuracy. Results suggest that MALDI-TOF MS and multivariate analysis are useful in determining authenticity of PAC from different sources and mixtures of PAC sources.