title: Aggregation properties of whey protein hydrolysates generated with Bacillus licheniformis proteinase activities.
abstract: Hydrolysis of whey protein concentrate (WPC) with Alcalase 2.4 L, a Bacillus licheniformis proteinase preparation, induces gelation. The aggregation behavior of WPC hydrolysates generated with Alcalase and Prolyve 1000, a Bacillus licheniformis proteinase that did not induce gelation, were studied by turbidity and particle size analysis. With the use of synthetic peptide substrates, it was shown that Alcalase contains a glutamyl endopeptidase (GE) activity not present in Prolyve. Comparison of the aggregation behavior of WPC hydrolysates generated with Alcalase, Prolyve, and combinations of Prolyve with a GE activity isolated from Alcalase showed that GE was responsible for the observed enzyme-induced peptide aggregation in Alcalase hydrolysates. Hydrolysates generated with Prolyve, having a degree of hydrolysis (DH) of 11.8% and 10.4% of peptide material greater than 10 kDa, could be induced to aggregate by the addition of GE. These results emphasize the contribution of enzyme specificity to the physicochemical and functional characteristics of proteinase hydrolysates of WPC.
authors.affiliation: Department of Life Sciences, University of Limerick, Ireland.
authors.forename: David
authors.initials: D
authors.lastname: Spellman
authors.forename: Patricia
authors.initials: P
authors.lastname: Kenny
authors.forename: Gerard
authors.initials: G
authors.lastname: O'Cuinn
authors.forename: Richard J
authors.initials: RJ
authors.lastname: FitzGerald
mesh_terms: D001407:Bacillus / Q000201:enzymology*; D002851:Chromatography, High Pressure Liquid; D006868:Hydrolysis; D008894:Milk Proteins / Q000737:chemistry* / Q000378:metabolism; D009391:Nephelometry and Turbidimetry; D010316:Particle Size; D010447:Peptide Hydrolases / Q000378:metabolism*; D013381:Subtilisins / Q000378:metabolism; D000067816:Whey Proteins
chemical_list: D008894:Milk Proteins; D000067816:Whey Proteins; D010447:Peptide Hydrolases; D013381:Subtilisins