title: Processing of soybean products by semipurified plant and microbial alpha-galactosidases.
abstract: 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.
authors.affiliation: BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG 36.570-000, Brazil.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Falkoski
authors.forename: Valéria M
authors.initials: VM
authors.lastname: Guimarães
authors.forename: Carina M
authors.initials: CM
authors.lastname: Callegari
authors.forename: Angélica P
authors.initials: AP
authors.lastname: Reis
authors.forename: Everaldo G
authors.initials: EG
authors.lastname: de Barros
authors.forename: Sebastião T
authors.initials: ST
authors.lastname: de Rezende
mesh_terms: 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*
chemical_list: D009844:Oligosaccharides; D000519:alpha-Galactosidase; D005690:Galactose