Feasibility and application of liquid–liquid extraction combined with gas chromatography–mass spectrometry for the analysis of phenolic acids from grape polyphenols degraded by human faecal microbiota

• Published in: Food chemistry 2012-07, Vol.133 (2), p.526-535
• Main Authors: Muñoz-González, C., Moreno-Arribas, M.V., Rodríguez-Bencomo, J.J., Cueva, C., Martín Álvarez, P.J., Bartolomé, B., Pozo-Bayón, M.A.
• Format: Article
• Language: English
• Subjects: Adult; Anaerobic conditions; Biological and medical sciences; chemical structure; Feasibility Studies; feces; Feces - microbiology; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry - methods; Grape polyphenols; grape seed extract; grapes; Gut microbiota; Healthy Volunteers; Humans; Hydroxybenzoates - analysis; Hydroxybenzoates - metabolism; Liquid-Liquid Extraction - methods; LLE–GC–EI-MS; metabolites; Microbiota; phenolic acids; Phenolic metabolites; polyphenols; Polyphenols - analysis; Polyphenols - metabolism; quantitative analysis; spectroscopy; Vitaceae; Vitis - chemistry; Vitis - microbiology; volunteers
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2012.01.020

► LLE–GC–EI-MS is a suitable method for the characterisation of gut phenolic metabolites. ► Anaerobic incubations of a commercial grape seed extracts with human faeces. ► Gut microbiota prefer flavan-3-ol monomers than procyanidin oligomers. ► Large interindividual differences in the bioconversion rate. In this study the feasibility of a LLE–GC–EI-MS method for the analysis of 43 phenolic acids belonging to different chemical structure families which have been described in the literature as microbial-derived metabolites after consumption of dietary polyphenols was proved. In addition, the method was applied for the characterisation of phenolic metabolites resulting from the incubation, in anaerobic conditions, of a commercial grape seed extract (GSE) and their corresponding flavan-3-ol monomeric (GSE-M) and oligomeric (GSE-O) fractions with human faeces from healthy volunteers (n=3). The method showed average values of repeatability and reproducibility of 5.0% and 6.3%, respectively, adequate and low detection (1.8–30.8μgL−1) and quantification limits (6.0–102.8μgL−1) and good recovery values (95%, as average value). A total of 27 phenolic acids were identified in the faecal solutions after incubation with the grape seed extracts. In general, faecal samples incubated with GSE and GSE-M (monomeric fraction) yield a higher formation of phenolic acids compared to the samples incubated with the oligomer fraction (GSE-O).