title: Improving surface functional properties of tofu whey-derived peptides by chemical modification with fatty acids.
abstract: Effect of acylation with saturated fatty acids on surface functional properties of tofu whey-derived peptides was investigated. Tofu whey (TW) and soy proteins (7S, 11S, and acid-precipitated soy protein [APP]) were hydrolyzed by Protease M 'Amano' G, and resulting peptide mixtures were acylated with esterified fatty acids of different chain length (6C to 18C) to form a covalent linkage between the carboxyl group of fatty acid and the free amino groups of peptide. Acylation significantly (P < 0.05) increased emulsifying properties of 7S, 11S, and APP peptides independent of fatty acid chain length. Acylation decreased water binding capacity although oil binding capacity of acylated tofu whey ultra filtered fraction (UFTW < 3 kDa), 7S- and 11S-peptides were improved compared to native peptides. 7S peptides acylated with long chain fatty acids had shown significant higher surface hydrophobicity as in contrast with acylated UFTW < 3 kDa and APP peptides. Fluorescence spectra studies revealed structural conformation of acylated soy peptides as compared to native peptides. This study shows that chemical modification with fatty acids can further affect functional properties of soy proteins.
authors.affiliation: Department of Bioscience and Biotechnology, Shinshu University, 8304 Minamiminowamura, Nagano, Japan.
authors.forename: Athanasia Oswald
authors.initials: AO
authors.lastname: Matemu
authors.forename: Shigeru
authors.initials: S
authors.lastname: Katayama
authors.forename: Hisataka
authors.initials: H
authors.lastname: Kayahara
authors.forename: Hisashi
authors.initials: H
authors.lastname: Murasawa
authors.forename: Soichiro
authors.initials: S
authors.lastname: Nakamura
mesh_terms: D000215:Acylation; D052179:Antigens, Plant / Q000737:chemistry / Q000378:metabolism; D055598:Chemical Phenomena; D045703:Emulsifying Agents / Q000737:chemistry* / Q000191:economics / Q000302:isolation & purification / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry*; D005503:Food Additives / Q000737:chemistry* / Q000191:economics / Q000302:isolation & purification / Q000378:metabolism; D005525:Food-Processing Industry / Q000191:economics; D005916:Globulins / Q000737:chemistry / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D007220:Industrial Waste / Q000032:analysis / Q000191:economics; D055666:Lipopeptides / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D014674:Plant Proteins, Dietary / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D011487:Protein Conformation; D055314:Seed Storage Proteins / Q000737:chemistry / Q000378:metabolism; D030262:Soybean Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D013499:Surface Properties; D014462:Ultrafiltration; D014867:Water / Q000032:analysis
chemical_list: D052179:Antigens, Plant; D045703:Emulsifying Agents; D005227:Fatty Acids; D005503:Food Additives; D005916:Globulins; D007220:Industrial Waste; D055666:Lipopeptides; D010446:Peptide Fragments; D014674:Plant Proteins, Dietary; D055314:Seed Storage Proteins; D030262:Soybean Proteins; C013894:beta-conglycinin protein, Glycine max; D014867:Water; C011474:glycinin; D010450:Endopeptidases