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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847
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Item Propriedades físico-químicas de polifenoloxidase de feijão (Phaseolus vulgaris L.)(Food Science and Technology, 2001-01) Gomes, Maria Regina Araújo; Oliveira, Maria Goreti de Almeida; Carneiro, Geraldo Estevam Souza; Barros, Everaldo Gonçalves de; Moreira, Maurílio AlvesAs atividades de polifenoloxidases do feijão (Phaseolus vulgaris L.), cultivares: (Aruã, Aporé, A774, Carioca, Diamante Negro, Ouro Branco, Pérola, RAO 33 e Rudá) foram investigadas sob condições de cinética enzimática. O pH ótimo para o extrato bruto das nove cultivares foi em pH 7,2 utilizando catecol como substrato. Nenhuma atividade PPO foi observada na presença do ácido gálico ou D,L- DOPA.Item Biochemical properties of soybean leaf lipoxygenases: Presence of soluble and membrane-bound forms(Plant Physiology and Biochemistry, 2001-02) Baracat-Pereira, Maria Cristina; Oliveira, Maria Goreti de Almeida; Barros, Everaldo Gonçalves de; Moreira, Maurílio Alves; Santoro, Marcelo MatosLipoxygenases (EC 1.13.11.12, LOX) extracted from soybean leaves (Glycine max [L.] Merrill cv. IAC-100) at pH 6.5 showed low stability. Given the importance of correlating the biochemical roles with the physiological characteristics of each LOX isoenzyme, this work evaluates biochemical characteristics and stability conditions of these enzymes in order to plan a purification procedure. LOX activity (A234 at pH 6.0) increased four to five times when 0.25 % (v/v) Triton X-100, 1 % (w/v) polyvinylpyrrolidone, and 1 mM phenylmethylsulfonyl fluoride were added to leaf macerates. Fe2+ (1 mM) stabilised LOX (70.3 % of activity recovered after 48 h storage). Ammonium sulphate fractionation (35–65 % saturation) increased specific LOX activity five times and stabilised the enzymes. Two optimum LOX activities were observed at pH 6.0–6.5 and 4.0–5.0, and the greater storage stability was at pH 6.5 (after 24–28 h storage at different pH values). The results suggest the presence of at least two different forms of the enzyme. The forms of LOX that are active at acidic pH are more stable than the ones that are active at neutral pH. These stable forms were extracted in absence of detergents (soluble forms), while the forms of LOX that are active at pH 6.0–6.5 are unstable forms specially extracted in presence of Triton X-100, and possibly correspond to membrane-bound proteins.Item Treatment of soy milk with Debaryomyces hansenii cells immobilised in alginate(Food Chemistry, 2009-05-15) Souza Júnior, Waldeck Campanha de; Rezende, Sebastião Tavares de; Viana, Pollyanna Amaral; Falkoski, Daniel Luciano; Reis, Angélica Pataro; Machado, Solimar Gonçalves; Barros, Everaldo Gonçalves de; Guimarães, Valéria MontezeWhole cells of Debaryomyces hansenii UFV-1 were permeabilised with ethanol and immobilised in calcium alginate hydrogel. The optimum pH and temperature for α-galactosidase activities of permeabilised free (PFC) and permeabilised immobilised cells (PIC) were 4.5 and 60 °C; and 4.0 and 70 °C, respectively. PIC α-galactosidase was more stable than that of PFC. The incubation of PIC at 60 and 70 °C promoted an increase in α-galactosidase activity. The α-galactosidase activity was maintained when PIC was used in three repeated batches. The Km values for PIC and PFC α-galactosidases, with ρNPαGal, were 0.82 mM and 0.30 mM, respectively. Soy milk treatment with PIC for 6 h at 60 °C promoted 100% hydrolysis of raffinose oligosaccharides.Item Ligação gênica da resistência à ferrugem e à antracnose na variedade de feijão ouro negro(Revista Ceres, 2000-07) Moreira, Maurílio Alves; Ragagnin, Vilmar Antônio; Corrêa, Ronan Xavier; Vinhadelli, Wender Santos; Barros, Everaldo Gonçalves de; Faleiro, Fábio GelapeA variedade Ouro Negro tem sido utilizada no Programa de Melhoramento do Feijoeiro (Phaseolus vulgaris L.) da UFV/BIOAGRO/EPAMIG como fonte de genes de resistência à ferrugem e à antracnose. Para melhor entendimento da herança e da organização desses genes de resistência, foi analisada a segregação de 231 plantas RC3F2 com relação à resistência a essas duas doenças. As plantas RC3F2, com aproximadamente 10 dias, foram inoculadas com uma mistura de uredosporos de Uromyces appendiculatus var appendiculatus coletados em diferentes municípios de Minas Gerais Após a avaliação da resistência à ferrugem, as mesmas plantas RC3F2 foram inoculadas com a raça 89 de Colletotrichum lindemuthiamun. A análise dos sintomas evidenciou que tanto a resistência à ferrugem quanto à antracnose são controladas por fatores dominantes únicos. Foi também observado que os genes de resistência à ferrugem e à antracnose presentes Ouro Negro estão ligados entre si. Para melhor entendimento da organização genômica de tais genes, estão sendo realizados, nos laboratórios do BIOAGRO-UFV, trabalhos mais detalhados envolvendo marcadores moleculares e populações segregantes adequadas.Item Covalent immobilization of α-Galactosidase from Penicillium griseoroseum and its application in Oligosaccharides Hydrolysis(Applied Biochemistry and Biotechnology, 2008-10-21) Falkoski, Daniel Luciano; Guimarães, Valéria Monteze; Queiroz, Marisa Vieira de; Araújo, Elza Fernandes de; Almeida, Maíra Nicolau de; Barros, Everaldo Gonçalves de; Rezende, Sebastião Tavares dePartially purified α-Galactosidase from Penicillium griseoroseum was immobilized onto modified silica using glutaraldehyde linkages. The effective activity of immobilized enzyme was 33%. Free and immobilized α-galactosidase showed optimal activity at 45 °C and pH values of 5 and 4, respectively. Immobilized α-galactosidase was more stable at higher temperatures and pH values. Immobilized α-galactosidase from P. griseoroseum maintained 100% activity after 24 h of incubation at 40 °C, while free enzyme showed only 32% activity under the same incubation conditions. Defatted soybean flour was treated with free and immobilized α-galactosidase in batch reactors. After 8 h of incubation, stachyose was completely hydrolyzed in both treatments. After 8 h of incubation, 39% and 70% of raffinose was hydrolyzed with free and immobilized α-galactosidase respectively. Immobilized α-galactosidase was reutilized eight times without any decrease in its activity.Item Biochemical composition and indigestible oligosaccharides in Phaseolus vulgaris L. seeds(Plant Foods for Human Nutrition, 2006-06-20) Fialho, Lílian da Silva; Guimarães, Valéria Monteze; Barros, Everaldo Gonçalves de; Moreira, Maurilio Alves; Dias, Luiz Antônio dos Santos; Oliveira, Maria Goreti de Almeida; José, Inês Chamel; Rezende, Sebastião Tavares deCommon beans have a high nutritional value, but contain galactooligosaccharides (GO), which cause flatulence and intestinal discomfort in humans. The biochemical composition of ten bean cultivars was determined to select those of high protein and low GO contents. The cultivars varied in carbohydrate (47.02–60.17%), GO (3.12 – 5.71%), protein (22.17–33.50%), lipid (1.13–1.81%), moisture (11.42–12.93%) and ash contents (4.08–5.61%). ‘Mexico 222’ presented the highest α-galactosidase activity. Protein and GO contents were positively correlated. ‘Perry Marrow’ combined high protein and low GO concentrations, indicating it can be used in improvement programs aiming at high-quality cultivars for human consumption.