Binding of homologous and heterological classes of flavours with salt-extracted canola protein isolates
(CPIs) and pea protein isolates (PPIs) and the effect of heat treatment on their binding were investigated
using GC/MS. Competitive binding was observed when homologous ketones were added to CPIs and PPIs
and when homologous aldehydes were mixed with CPIs. Ketone mixtures performed differently than
aldehydes in that 2-octanone retained more effectively than 2-heptanone and 2-hexanone by CPIs and
PPIs, whereas CPIs exhibited incremental affinity to hexanal rather than heptanal and octanal. For PPIs,
the presence of aldehydes increased the proteins' overall flavour-binding capacities probably due to
partial unfolding of proteins revealing more binding sites as manifested by the decreased DH from the
DSC studies. Binding of hexanal to CPIs was significantly increased with increased heating time at 95 C,
while a transition of 2-octanone retention from increasing to decreasing inferred heat-induced protein
association released previously bound 2-octanone. Heat treatment at 95 C for 30 min promoted greater
competitive binding when mixed ketones and hexanal and 2-hexanone mixtures interacted with CPIs
and PPIs, respectively, while dramatic increases of binding of aldehyde mixtures was observed thought
out the heating processes.