Simplified process for soybean glycinin and beta-conglycinin fractionation.
A simplification of the pilot-plant scale modified Nagano method yielding two protein fractions, glycinin and beta-conglycinin, by pH adjustment and ultrafiltration membrane separation was developed and compared with our pilot-plant-scale modified Nagano procedure and with a soy protein isolate pilot-plant procedure as our reference process. Two protein fractions, glycinin and beta-conglycinin, were produced from our simplified process and compared to the three protein fractions, glycinin, beta-conglycinin, and an intermediate protein mixture, produced with the modified Nagano method. The pilot-plant yields of glycinin, beta-conglycinin, and intermediate mixture fractions from the modified Nagano method were 9.4, 10.3, and 4.8% [dry basis (db)], respectively. The yield of glycinin fraction of the simplified method was 9.7% (db), and it had a protein content and purity similar to those obtained with the modified Nagano method. The yield of the beta-conglycinin fraction was 19.6% (db), which was twice that of the modified Nagano process. The protein content of beta-conglycinin was 91.6% (db), and the purity was 62.6% of the protein content, which was 9% lower in purity than the modified Nagano method. Process optimization of the simplified method suggested the best operating conditions for the membrane filtration system were 20-25 psi inlet pressure and 200-250 L/min ultrafiltration recirculation speeds.
Wu
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Department of Food Science and Human Nutrition, Center for Crops Utilization Research, Iowa State University, Ames, Iowa 50011, USA.
Murphy
P A
PA
Johnson
L A
LA
Reuber
M A
MA
Fratzke
A R
AR
D052179:Antigens, Plant; D005511:Food Handling / Q000379:methods*; D005916:Globulins / Q000302:isolation & purification*; D055314:Seed Storage Proteins; D030262:Soybean Proteins; D013025:Glycine max / Q000737:chemistry*
D052179:Antigens, Plant; D005916:Globulins; D055314:Seed Storage Proteins; D030262:Soybean Proteins; C013894:beta-conglycinin protein, Glycine max; C011474:glycinin