title: [The effect of bacterial proteases on milk proteins].
abstract: The effect of proteolytic microflora on milk protein in fresh cow's milk was studied immediately after milking. The hydrolytic activity was measured by Lowry's method. When the samples were stored for 24 and 48 hours at 4 degrees C, the average value of tyrosine increased from the initial level of 0.37 mg per ml (immediately after milking) to 0.798 mg per ml (after 24 hours) and 0.811 mg per ml (after 48 hours). In milk kept at room temperature the tyrosine values were 0.865 mg per ml and 1.21 mg per ml, respectively. Higher bacterial protease activities were recorded during the first 24 hours of storage. No relationship was statistically demonstrated between tyrosine content and the number of proteolytic microorganisms in milk.
mesh_terms: D000818:Animals; D001419:Bacteria / Q000201:enzymology*; D002417:Cattle; D008892:Milk / Q000201:enzymology / Q000382:microbiology*; D008894:Milk Proteins / Q000032:analysis*; D010447:Peptide Hydrolases / Q000032:analysis*
chemical_list: D008894:Milk Proteins; D010447:Peptide Hydrolases
vernacular_title: Vliv bakteriálních proteáz na mlécnou bílkovinu.