ISSN:
1365-2621
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Purified red blood cell concentrates (RBC), prepared by ultrafiltration and diafiltration (Delaney, 1977) were spray dried at air inlet temperatures of 185°C. the spray dried powders contained c. 95%‘true’ protein, c. 0.62% non-protein nitrogen, c. 1.7% fat, c. 1.6% minerals and c. 2% moisture. the purification processes effected a reduction of c. 60% in the content of non-protein material in the red cells. Red cell protein contained adequate levels of the essential amino acids, threonine, tryptophan, valine, leucine, phenylalanine and lysine. Isoleucine and methionine plus cyst(e)ine were the limiting amino acids. RBC powders exhibited protein solubilities in water of 75-95% over the pH range 2–10. Protein solubility was at a minimum at pH 7.2. Ionic background had a very marked effect on protein solubility in water at pH 3.0 (solubility fell from c. 95% to c. 3% in 4.0 m NaCl) but little effect at pH 8.0. Coagulation of red cell concentrate proteins occurred at temperatures in the range of 47–55°C. the degree and rate of coagulation was dependent upon the concentration of proteins present. At pH values of 4 and 10 no coagulation occurred with a 5% RBC dispersion during heating at 55°C for upwards to 150 min. Ultrafiltered/diafiltered RBC powder products contained a higher proportion of particles in the 106 to 〈45 μm size range than did controls. Adsorption and desorption isotherms for RBC powders were determined. the BET monolayer value for RBC powders was 6.5–6.7%.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1977.tb00118.x
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