1H-13C HSQC-NMR Analysis of Cranberry (Vaccinium Macrocarpon) Juice Defines the Chemical Composition of Juice Precipitate

Shelf-stable cranberry juice precipitate has not beenwell characterized.Here, we describe using H-1-C-13 heteronuclearsingle quantum coherence-nuclear magnetic resonance (HSQC-NMR)spectroscopy for cranberry juice analysis, focusing on proanthocyanidinsand the precipitate. HSQC-NMR cross-peaks from juices werecategorized as aliphatic, olefinic, aromatic, carbohydrate backbone,or anomeric signals. An average cranberry juice precipitate had significantlymore aromatic and significantly less carbohydrate backbone signalsthan an average supernatant. The precipitate was a collection of biomoleculesheld together by a mix of weak and strong intermolecular forces. Proanthocyanidinsignals from precipitates of juices showed 22 & PLUSMN; 2 to 29.9 & PLUSMN;0.7% A-type interflavan linkages and 34 & PLUSMN; 2 to 48 & PLUSMN; 3% offlavan-3-ol units with trans stereochemistry between the C2 and C3positions. Based on this work, H-1-(13)CHSQC-NMR is useful to analyze cranberry juice and reveals thecomplex chemical nature of components in the soluble and insolublephases.