Probing the molecular forces involved in binding of selected volatile flavour compounds to salt-extracted pea proteins.
Molecular interactions between heterologous classes of flavour compounds with salt-extracted pea protein isolates (PPIs) were determined using various bond disrupting agents followed by GC/MS analysis. Flavour bound by proteins decreased in the order: dibutyl disulfide>octanal>hexyl acetate>2-octanone=benzaldehyde. Benzaldehyde, 2-octanone and hexyl acetate interacted non-covalently with PPIs, whereas octanal bound PPIs via covalent and non-covalent forces. Dibutyl disulfide reacted with PPIs covalently, as its retention was not diminished by urea and guanidine hydrochloride. Using propylene glycol, H-bonding and ionic interactions were implicated for hexyl acetate, benzaldehyde, and 2-octanone. A protein-destabilising salt (Cl3CCOONa) reduced bindings for 2-octanone, hexyl acetate, and benzaldehyde; however, retention for octanal and dibutyl disulfide increased. Conversely, a protein-stabilising salt (Na2SO4) enhanced retention for benzaldehyde, 2-octanone, hexyl acetate and octanal. Formation of a volatile flavour by-product, 1-butanethiol, from dibutyl disulfide when PPIs were treated with dithiothreitol indicated occurrence of sulfhydryl-disulfide interchange reactions.
Department of Food Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. Electronic address: umwan537@myumanitoba.ca.
Kun
K
Wang
Department of Food Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. Electronic address: susan.arntfield@umanitoba.ca.
Susan D
SD
Arntfield
D000447:Aldehydes / Q000737:chemistry*; D001547:Benzaldehydes / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D019791:Guanidine / Q000737:chemistry; D006860:Hydrogen Bonding; D007659:Ketones / Q000737:chemistry*; D018532:Pisum sativum / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry*; D019946:Propylene Glycol / Q000737:chemistry; D019163:Reducing Agents / Q000737:chemistry; D017673:Sodium Chloride, Dietary; D013649:Taste; D014508:Urea / Q000737:chemistry; D055549:Volatile Organic Compounds / Q000737:chemistry*
D000447:Aldehydes; D001547:Benzaldehydes; D004220:Disulfides; D007659:Ketones; D010940:Plant Proteins; D019163:Reducing Agents; D017673:Sodium Chloride, Dietary; D055549:Volatile Organic Compounds; D019946:Propylene Glycol; D014508:Urea; C037075:2-octanone; D019791:Guanidine; C032175:benzaldehyde; C031639:caprylic aldehyde
Flavour retention and release; Molecular forces; Pea protein; Protein-flavour binding