Processing of soybean products by semipurified plant and microbial alpha-galactosidases.
Galactooligosaccharides (GO) are responsible for intestinal disturbances following ingestion of legume-derived products. Enzymatic reduction of GO level in these products is highly desirable to improve their acceptance. For this purpose, plant and microbial semipurified alpha-galactosidases were used for GO hydrolysis in soybean flour and soy molasses. alpha-Galactosidases from soybean germinating seeds, Aspergillus terreus, and Penicillium griseoroseum presented maximal activities at pH 4.0-5.0 and 45-65 degrees C. The KM,app values determined for raffinose by the soybean, A. terreus, and P. griseoroseum alpha-galactosidases were 3.44, 19.39, and 20.67 mM, respectively. The enzymes were completely inhibited by Ag+ and Hg2+, whereas only soybean enzyme was inhibited by galactose. A. terreus alpha-galactosidase was more thermostable than the enzymes from the other two sources. This enzyme maintained about 100% of its original activity after 3 h at 60 C. The microbial alpha-galactosidases were more efficient for reducing GO in soybean flour and soy molasses than soybean enzyme.
Falkoski
Daniel L
DL
BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG 36.570-000, Brazil.
Guimarães
Valéria M
VM
Callegari
Carina M
CM
Reis
Angélica P
AP
de Barros
Everaldo G
EG
de Rezende
Sebastião T
ST
D001230:Aspergillus / Q000201:enzymology; D005511:Food Handling / Q000379:methods*; D005690:Galactose / Q000378:metabolism; D009844:Oligosaccharides / Q000378:metabolism; D010407:Penicillium / Q000201:enzymology; D012639:Seeds / Q000201:enzymology; D045730:Soy Foods; D013025:Glycine max / Q000201:enzymology / Q000378:metabolism*; D000519:alpha-Galactosidase / Q000378:metabolism*
D009844:Oligosaccharides; D000519:alpha-Galactosidase; D005690:Galactose