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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847
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Item Hydrolysis of oligosaccharides in soybean flour by soybean α-galactosidase(Food Chemistry, 2015-12) Guimarães, Valéria Monteze; José, Inês Chamel; Oliveira, Maria Goreti de Almeida e; Oliveira, Maria Goreti de Almeida e; Barros, Everaldo Gonçalves de; Moreira, Maurílio Alves; Viana, Simone de Fátima; Rezende, Sebastião Tavares deRaffinose oligosaccharides (ROs) make up a substantial part (40%) of the soluble sugars found in soybean seeds and are responsible for flatulence after the ingestion of soybean and other legumes. Consequently, soy-based foods would find a broader approval if the ROs were removed from soybean products or hydrolysed by α-galactosidases. During soybean seed germination, of content the ROs decrease substantially, while the α-galactosidase activity increases. α-Galactosidase was partially purified from germinating seeds by partition in an aqueous two-phase system and ion-exchange chromatography. The enzyme preparation presented maximal activities against ρ-nitrophenyl-α-d-galactopyranoside (ρNPGal) at 60 °C and a pH of 5.0 and the KM app values for ρNPGal, melibiose, and raffinose of the enzyme preparation were 0.33, 0.42, and 6.01 mM, respectively. The enzyme was highly inhibited by SDS, copper, and galactose. Hydrolysis of soybean flour ROs by enzyme preparation reduced the stachyose and raffinose contents by 72.3% and 89.2%, respectively, after incubation for 6 h at 40 °C.Item Removal of oligosaccharides in soybean flour and nutritional effects in rats(Food Chemistry, 2010-01-15) Brasil, Ana Paula Rodrigues; Rezende, Sebastião Tavares de; Pelúzio, Maria do Carmo Gouveia; Guimarães, Valéria MontezeThe objectives of this work were to establish a safe and economically viable process for the removal of raffinose oligosaccharides (RO) from soy flour and compare the effects of RO elimination from diets with regard to nutritional parameters by testing in Wistar rats. Debaryomyces hansenii UFV-1 was cultivated in suspension of defatted soy flour (1:10 w/v). An increase in α-galactosidase activity was observed in the medium, with a consequent decrease in the RO concentration. A total reduction of RO was achieved at 36 h of incubation. The diet containing soy flour free of RO presented higher digestibility, 91.28%, in relation to the diet containing soy flour with RO, 87.14%. However, the removal of the oligosaccharides from the diet did not promote a significant improvement in the values of weight gain, and other nutritional parameters tested on rats, during the experimental period of 14 days.Item Purification and characterization of Aspergillus terreus α-Galactosidases and their use for hydrolysis of Soymilk Oligosaccharides(Applied Biochemistry and Biotechnology, 2011-02-18) Ferreira, Joana Gasperazzo; Reis, Angélica Pataro; Guimarães, Valéria Monteze; Falkoski, Daniel Luciano; Silva Fialho, Lílian da; Rezende, Sebastião Tavares deα-Galactosidases has the potential to hydrolyze α-1-6 linkages in raffinose family oligosaccharides (RFO). Aspergillus terreus cells cultivated on wheat bran produced three extracellular forms of α-galactosidases (E1, E2, and E3). E1 and E2 α-galactosidases presented maximal activities at pH 5, while E3 α-galactosidase was more active at pH 5.5. The E1 and E2 enzymes showed stability for 6 h at pH 4–7. Maximal activities were determined at 60, 55, and 50°C, for E1, E2, and E3 α-galactosidase, respectively. E2 α-galactosidase retained 90% of its initial activity after 70 h at 50°C. The enzymes hydrolyzed ρNPGal, melibiose, raffinose and stachyose, and E1 and E2 enzymes were able to hydrolyze guar gum and locust bean gum substrates. E1 and E3 α-galactosidases were completely inhibited by Hg2+, Ag+, and Cu2+. The treatment of RFO present in soy milk with the enzymes showed that E1 α-galactosidase reduced the stachyose content to zero after 12 h of reaction, while E2 promoted total hydrolysis of raffinose. The complete removal of the oligosaccharides in soy milk could be reached by synergistic action of both enzymes