As an alternative to meat, legumes represent a promising alternative to fulfil both agrienvironmental issues and feeding the planet. Despite faba bean protein richness, several locks remain to its consumption. The main issue is its polyphenolic content that alter its organoleptic and physico-chemical products properties. Flavan-3-ols monomers (catechin, epicatechin and galloyl derivatives) and oligomers (proanthocyanidins) were detected in faba bean methanolic extract1 in genotypes dependant manner2 . Tannin depolymerization gave more information about their structure and mean degree of polymerization3. During transformation, seeds undergo alkalinization (pH8) to precipitate proteins and obtain proteins isolates. Such condition leads to polyphenol autoxidation that forms quinones and reactive intermediates able to interact with proteins. If it is well known that the non-covalent and covalent bounding4 depended on multiple factors (temperature, pH and conformation/type), the relevance of the polyphenolic pool oxidative status on the interaction determinism needed to be investigated. Here, we performed a metabolomics profiling of 12 faba beans genotypes. The study relied on both direct UHPLC-DAD-LTQ analysis or after a depolymerization step. Varieties were separated by chemometrics tools through their growth seasonality. We then used centrifugal partition chromatography and preparative HPLC to obtain a tannin-rich fraction that we set at pH8 for night in order to oxidize the polyphenolic pool. This fraction was then put into contact with a fraction of faba bean albumin enriched fraction and interactions were monitored. Fluorescence quenching was revealed and high molecular weight bands on gel electrophoresis were observed that proved that oxidized polyphenols covalently bounded to proteins.