Physicochemical characterisation of mung bean (Phaseolus aureus) protein isolates

Protein isolates were prepared from mung bean (Phaseolus aureus) flour by t wo different methods, ie by traditional alkaline water extraction/isoelectr ic precipation and by micellisation, and studied with regard to chemical co mposition and protein fractional distribution. Micellisation decreased the phytic acid content, whereas the 'isoelectrical' isolate preparation result ed in an increase in phytic acid. Using size exclusion liquid chromatograph y (SE-HPLC) and analytical ultracentrifugation, it has been shown that the major protein component in both isolates is a 7S globulin, which was most e nriched in the micelle isolate. The results of one- and two-dimensional SDS gel electrophoresis give evidence for the absence of interchain disulphide bonds in the polypeptide chains, which are typical for the 7S globulin cla ss. The presence of minor protein zones corresponding to disulphide-linked alpha and beta chains of 11S globulin-like storage proteins in the protein isolates has also been shown. (C) 2000 Society of Chemical Industry.