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.
Subject(s)
Emulsifying Agents/chemistry , Fatty Acids/chemistry , Food Additives/chemistry , Lipopeptides/chemistry , Peptide Fragments/chemistry , Plant Proteins, Dietary/chemistry , Soybean Proteins/chemistry , Acylation , Antigens, Plant/chemistry , Antigens, Plant/metabolism , Chemical Phenomena , Emulsifying Agents/economics , Emulsifying Agents/isolation & purification , Emulsifying Agents/metabolism , Endopeptidases/metabolism , Food Additives/economics , Food Additives/isolation & purification , Food Additives/metabolism , Food-Processing Industry/economics , Globulins/chemistry , Globulins/metabolism , Hydrophobic and Hydrophilic Interactions , Industrial Waste/analysis , Industrial Waste/economics , Lipopeptides/isolation & purification , Lipopeptides/metabolism , Molecular Weight , Peptide Fragments/isolation & purification , Peptide Fragments/metabolism , Plant Proteins, Dietary/isolation & purification , Plant Proteins, Dietary/metabolism , Protein Conformation , Seed Storage Proteins/chemistry , Seed Storage Proteins/metabolism , Soybean Proteins/isolation & purification , Soybean Proteins/metabolism , Surface Properties , Ultrafiltration , Water/analysisABSTRACT
The serum total cholesterol concentration was significantly lower in the kori-tofu feeding group than in the soy protein isolate (SPI) group, except on the 28th day of the experiment. The high-molecular-weight fraction (HMF) content of the kori-tofu protein was significantly higher than that of SPI. This difference in the HMF content may have influenced the cholesterol-lowering effect of the protein.
Subject(s)
Food Handling/methods , Soy Foods , Soybean Proteins , Animals , Arteriolosclerosis/diet therapy , Arteriolosclerosis/prevention & control , Body Weight , Caseins/analysis , Cholesterol, HDL/blood , Food, Formulated , Hypercholesterolemia/diet therapy , Hypercholesterolemia/prevention & control , Male , Molecular Weight , Rats , Rats, Wistar , Soy Foods/analysis , Soybean Proteins/analysis , Soybean Proteins/therapeutic use , Triglycerides/bloodABSTRACT
Peptide mixtures prepared from soybean ß-conglycinin (7S-peptides) were acylated with saturated fatty acids of different chain length (6C-18C) in order to improve their antiviral activity against Feline calicivirus (FCV) strain F9 which is a typical norovirus surrogate. Among the fatty acids varieties, it was revealed that 7S-peptides acylated with myristic and palmitic acids potently inhibited FCV replication. Myristorylation and palmitoylation of 7S-peptides kept host cells viability at 91.51% and 98.90%, respectively. The infectivity of FCV on Crandell-Reese feline kidney cells was further determined after exposure of initial titer of 10(6.47) TCID50/mL. Myristoylated and palmitoylated 7S-peptides significantly (P < 0.006) reduced FCV infectivity as compared to native 7S-peptides. Native 7S-peptides showed 25% FCV inhibitory activity while myristoylated and palmitoylated 7S-peptides exhibited 98.59% and 99.98% reduction in FCV infectivity, respectively. Myristoylated and palmitoylated 7S-peptides demonstrated higher anti-FCV activity in a wide range of concentration with complete reduction at 25 µg/mL. Surface hydrophobicity was significantly (P < 0.05) increased after attachment of long hydrocarbon fatty acids to 7S-peptides as supported by changes in fluorescence intensity. Enzymatic hydrolysis together with acylation will give an insight into surface and physiological functional lipopeptides derived from soy ß-conglycinin.
