Structural, physicochemical and interfacial stabilisation properties of ultrafiltered African yam bean (Sphenostylis stenocarpa) protein isolate compared with those of isoelectric protein isolate

摘要

Structural, Physicochemical and functional properties of ultrafiltered/diafiltered African yam bean (AYB) protein isolate (AYB(UD)) were determined. These were also compared with isoelectrically precipitated AYB protein isolate (AYB(ISO)). Both AYB(UD) and AYB(ISO) had the same X-ray diffraction (XRD peaks at 8.5 degrees and 19.5 degrees. The XRD profile for both AYB(ISO) and AYB(UD) showed partial crystalinity. Emission maximum (lambda(max)) of the intrinsic fluorescence spectra associated with tryptophan (Trp) residue in both AYB(UD) and AYB(ISO) was observed at 330 nm, indicating a Trp residue that was deeply buried in hydrophobic core. Circular dichroism (CD) spectra showed that there were more highly ordered structure of alpha-helix, beta and beta-turns in AYB(ISO) than AYB(UD). The surface hydrophobicity (H-o), emulsifying and foaming abilities of AYB(ISO) were significantly (p = 0.05) higher than those of AYB(UD). (C) 2016 Elsevier Ltd. All rights reserved.