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Application of 1 H‐NMR‐based metabolomics to the analysis of cranberry ( Vaccinium macrocarpon ) supplements
Author(s) -
Turbitt John R.,
Colson Kimberly L.,
Killday K. Brian,
Milstead Andrew,
Neto Catherine C.
Publication year - 2019
Publication title -
phytochemical analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 72
eISSN - 1099-1565
pISSN - 0958-0344
DOI - 10.1002/pca.2867
Subject(s) - chemistry , chemometrics , proton nmr , quinic acid , proanthocyanidin , chromatography , food science , metabolome , oleanolic acid , metabolomics , polyphenol , organic chemistry , antioxidant , medicine , alternative medicine , pathology
Abstract Introduction Commercial cranberry supplements provide a low‐sugar alternative to juices and sweetened fruit consumed for health benefits, but their phytochemical composition and associated biological activity varies depending on the source material and post‐harvest processing. Proton nuclear magnetic resonance ( 1 H‐NMR) is a rapid and environmentally friendly method of generating metabolic profiles of plant materials that may be used to authenticate cranberry products. Objective The 1 H NMR‐based chemometrics were used to characterise variations in metabolic profiles of cranberry supplements in comparison to a whole cranberry powder reference standard. Materials and Methods The secondary metabolite profiles of nine commercial cranberry supplements were compared to a whole cranberry powder reference standard, using 1 H‐NMR with Bruker AssureNMR software and principal component analysis (PCA). Content of selected triterpenoids and organic acids was determined by quantitative NMR. Total proanthocyanidins and anthocyanins were determined by established methods. Results PCA of 1 H‐NMR spectra showed overlap between the cranberry standard and three supplements, but most products varied substantially in metabolic profile. Metabolites contributing to the observed variance include citric acid and cranberry peel constituents ursolic acid, oleanolic acid and hyperoside. Ursolic, oleanolic, citric, quinic and malic acids were readily determined by quantitative 1 H‐NMR in the whole cranberry standard, but were below detection limits in many supplements. Proanthocyanidin and flavonoid content in several products was minimal or below detection limits. Conclusion The 1 H‐NMR chemometrics found significant variation in composition of characteristic cranberry metabolites among commercial preparations, reinforcing the need for reliable industry standards