The goal of this research was the characterisation of Vicia faba (broadbean)
protein isolates and related fractions in order to determine whether this grain legume could be used for production of high quality
protein products and other fractions rich in functional components. Alkaline extraction of the defatted seed flour, followed by precipitation at the isoelectric pH, yielded a 92%
protein isolate with a high oil absorption capacity. The contents of the
favism-inducing
glycosides,
vicine and
convicine, in the isolate were reduced by more than 99% as compared to the original flour, although the
amino acid composition was similar to that of the flour. Some of the by-products of
protein isolate production may also be of interest from a nutritional and functional point of view. Thus, the oil resulting from
hexane extraction of the flour is rich in
unsaturated fatty acids, and
polyphenols (resulting from extraction of the defatted flour with
acetone) showed a high
ABTS radical-scavenging activity. In addition, the solid residue (resulting from
protein solubilisation) was high in fibre and showed good water absorption. These results show good nutritional and functional properties in V. faba
protein isolates and related fractions, which may favour the revalorisation of this traditional bean crop.