title: Optimisation of the enzymatic hydrolysis of blood cells with a neutral protease.
abstract: For utilizing the blood cells (BCs) effectively, enzymatic hydrolysis was applied to produce the enzymatically hydrolyzed blood cells (EHBCs) by using a neutral protease as a catalyst. The results of the single-factor experiments showed optimal substrate concentration, enzyme to substrate ratio (E/S), pH, temperature, and incubation period were 1.00%, 0.10, 7.00, 50.00°C, and 12.00 h, respectively. The optimized hydrolysis conditions from response surface methodology (RSM) were pH 6.50, E/S 0.11, temperature 45.00°C, and incubation period 12.00 h. Under these conditions (substrate concentration 1.00%), the degree of hydrolysis (DH) was 35.06%. The free amino acids (FAAs) content of the EHBCs (35.24%) was 40.46 times higher than BCs while the total amino acids (TAAs) content was lower than BCs. The scores of lysine (human 0.87; pig 0.97), valine (human 1.42; pig 1.38), leucine (human 1.50; pig 1.90), tyrosine (human 0.84; pig 1.09), and histidine (human 2.17; pig 2.50) indicated that the EHBCs basically fulfilled the adult human and pig nutritional requirements. The calculated protein efficiency ratios (C-PERs) of the EHBCs were 3.94, 6.19, 21.73, and 2.04. In summary, the EHBCs were produced successfully with optimized conditions and could be a novel protein source for humans and pigs.
authors.affiliation: Laboratory of Biotechnology, Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China.
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Zheng
authors.forename: Qiushi
authors.initials: Q
authors.lastname: Chen
authors.forename: Anshan
authors.initials: A
authors.lastname: Shan
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry*; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008297:Male; D008666:Metalloendopeptidases / Q000737:chemistry*; D059748:Proteolysis; D013552:Swine
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D008666:Metalloendopeptidases; C071298:bacillolysin