Format

Send to

Choose Destination
Food Res Int. 2019 Feb;116:786-794. doi: 10.1016/j.foodres.2018.09.012. Epub 2018 Sep 11.

Edible nuts deliver polyphenols and their transformation products to the large intestine: An in vitro fermentation model combining targeted/untargeted metabolomics.

Author information

1
Department of Animal Science, Food and Nutrition, Università Cattolica del Sacro Cuore, Piacenza 29122, Italy; Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Piacenza 29122, Italy; Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada. Electronic address: gabriele.rocchetti@unicatt.it.
2
Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
3
Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Piacenza 29122, Italy.
4
Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Piacenza 29122, Italy. Electronic address: luigi.lucini@unicatt.it.
5
Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada; Department of Computing Science, University of Alberta, Edmonton, AB T6G 2E8, Canada.

Abstract

The fate of polyphenols from edible tree nuts was investigated using a simulated in vitro intestinal fermentation system. The digested food matrix was fermented for 48 h and the changes in the phenolic profiles were evaluated by both untargeted UHPLC-QTOF and targeted UHPLC-Orbitrap mass spectrometry. The untargeted metabolomics approach allowed us to monitor the comprehensive changes in phenolic profiles from 0 up to 48 h of in vitro fermentation. Multivariate statistics (i.e., orthogonal projection to latent structures discriminant analysis) applied to this untargeted data allowed us to identify the most discriminating phenolic metabolites and to further understand the colonic transformation pathways involved. In particular, 13 putatively identified compounds derived from flavonoids, lignans and phenolic acids were found to have the highest discrimination potential. Six phenolic metabolites were then quantified by means of targeted metabolomics (using a UHPLC-Orbitrap). These metabolites included 3,4-dihydroxyphenylacetic acid, 4-hydroxybenzoic acid, hippuric acid, caffeic acid, protocatechuic acid and protocatechuic aldehyde. Using the targeted data, a clear matrix effect was observed over time, with an increase of some phenolic metabolites moving from 8 to 48 h of in vitro fermentation. Based on these data, catabolic pathways for colonic microbial degradation of flavonoids, hydroxycinnamic acids, tyrosols and lignans are proposed. Our findings show that edible tree nuts deliver polyphenols to the colon, where several microbial transformations occur that lead to smaller phenolic metabolites being observed. Furthermore, we found that the combined use of targeted and untargeted metabolomics can be particularly effective for investigating the fate of polyphenols in the large intestine.

KEYWORDS:

Food metabolomics; In vitro fermentation; Nuts; Polyphenols; UHPLC-Orbitrap; UHPLC-QTOF

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center