Effect of inulin on the growth and metabolism of a probiotic strain of Lactobacillus rhamnosus in co-culture with Streptococcus thermophilus

Metabolic studies are very important to improve quality of functional dairy products. For this purpose, the behaviors of pure cultures of Streptococcus thermophilus (St) and Lactobacillus rhamnosus (Lr) as well a co-culture of them (St-Lr) were investigated during skim milk fermentation, and the inulin effect as prebiotic was assessed. Lr was able to metabolize 6 g/100 g more galactose than St and St-Lr. Final lactic acid production by Lr was higher (9.8 g/L) compared to St (9.1 g/L) and St-Lr (9.1 g/L). Acetic acid concentration varied from 0.8 g/L (St-Lr) to 1.5 g/L (Lr) and that of ethanol from only 0.2 g/L (St-Lr) to 0.4 g/L (Lr), which suggests the occurrence in Lr of a NADH oxidase activity and citrate co-metabolization via pyruvate, both dissipating a part of the reducing power. Diacetyl and acetoin accumulated at the highest levels (18.4 and 0.8 mg/L, respectively) with St-Lr, which suggests possible synergistic interactions between these microorganisms as well as the Lr capability of co-metabolizing citrate in the presence of lactose. Inulin stimulated both biomass growth and levels of all end-products, as the likely result of fructose release from its partial hydrolysis and subsequent metabolization as an additional carbon and energy source. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.Sao Paulo State Research Foundation (FAPESP)CAPES (Coordination of Improvement of Higher Education

Kefir administration reduced progression of renal injury in STZ-diabetic rats by lowering oxidative stress

This study aimed at assessing the effects of Kefir, a probiotic fermented milk, on oxidative stress in diabetic animals. the induction of diabetes was achieved in adult male Wistar rats using streptozotocin (STZ). the animals were distributed into four groups as follows: control (CTL); control Kefir (CTLK); diabetic (DM) and diabetic Kefir (DMK). Starting on the 5th day of diabetes, Kefir was administered by daily gavage at a dose of 1.8 mL/day for 8 weeks. Before and after Kefir treatment, the rats were placed in individual metabolic cages to obtain blood and urine samples to evaluate urea, creatinine, proteinuria, nitric oxide (NO), thiobarbituric acid reactive substances (TBARS) and C-reactive protein (CRP). After sacrificing the animals, the renal cortex was removed for histology, oxidative stress and NOS evaluation. When compared to CTL rats, DM rats showed increased levels of glycemia, plasmatic urea, proteinuria, renal NO, superoxide anion, TBARS, and plasmatic CRP; also demonstrated a reduction in urinary urea, creatinine, and NO. However, DMK rats showed a significant improvement in most of these parameters. Despite the lack of differences observed in the expression of endothelial NO synthase (eNOS), the expression of inducible NO synthase (iNOS) was significantly lower in the DMK group when compared to DM rats, as assessed by Western blot analysis. Moreover, the DMK group presented a significant reduction of glycogen accumulation within the renal tubules when compared to the DM group. These results indicate that Kefir treatment may contribute to better control of glycemia and oxidative stress, which is associated with the amelioration of renal function, suggesting its use as a non-pharmacological adjuvant to delay the progression of diabetic complications. (C) 2014 Elsevier Inc. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundacao de Apoio a Universidade Federal de São Paulo (FAP-Unifesp)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, BR-04023900 São Paulo, BrazilUniv São Paulo, Coll Publ Hlth, Dept Nutr, São Paulo, BrazilUniv São Paulo, Dept Biochem & Pharmaceut Technol, São Paulo, BrazilUniv São Paulo, Dept Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, BR-04023900 São Paulo, BrazilWeb of Scienc

Association of a probiotic to a Helicobacter pylori eradication regimen does not increase efficacy or decreases the adverse effects of the treatment: a prospective, randomized, double-blind, placebo-controlled study

Abstract\ud \ud \ud \ud Background\ud \ud The treatment for the eradication of Helicobacter pylori (H. pylori) is complex; full effectiveness is rarely achieved and it has many adverse effects. In developing countries, increased resistance to antibiotics and its cost make eradication more difficult. Probiotics can reduce adverse effects and improve the infection treatment efficacy.\ud If the first-line therapy fails a second-line treatment using tetracycline, furazolidone and proton-pump inhibitors has been effective and low cost in Brazil; however it implies in a lot of adverse effects. The aim of this study was to minimize the adverse effects and increase the eradication rate applying the association of a probiotic compound to second-line therapy regimen.\ud \ud \ud \ud Methods\ud \ud Patients with peptic ulcer or functional dyspepsia infected by H. pylori were randomized to treatment with the furazolidone, tetracycline and lansoprazole regimen, twice a day for 7 days. In a double-blind study, patients received placebo or a probiotic compound (Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum and Streptococcus faecium) in capsules, twice a day for 30 days. A symptom questionnaire was administered in day zero, after completion of antibiotic therapy, after the probiotic use and eight weeks after the end of the treatment. Upper digestive endoscopy, histological assessment, rapid urease test and breath test were performed before and eight weeks after eradication treatment.\ud \ud \ud \ud Results\ud \ud One hundred and seven patients were enrolled: 21 men with active probiotic and 19 with placebo plus 34 women with active probiotic and 33 with placebo comprising a total of 55 patients with active probiotic and 52 with placebo. Fifty-one patients had peptic ulcer and 56 were diagnosed as functional dyspepsia. The per-protocol eradication rate with active probiotic was 89.8% and with placebo, 85.1% (p = 0.49); per intention to treat, 81.8% and 79.6%, respectively (p = 0.53). The rate of adverse effects at 7 days with the active probiotic was 59.3% and 71.2% with placebo (p = 0.20). At 30 days, it was 44.9% and 60.4%, respectively (p = 0.08).\ud \ud \ud \ud Conclusions\ud \ud The use of this probiotic compound compared to placebo in the proposed regimen in Brazilian patients with peptic ulcer or functional dyspepsia showed no significant difference in efficacy or adverse effects.\ud \ud \ud \ud Trial registration\ud \ud Current Controlled Trials ISRCTN04714018Drugs providing supported from Medley Indústria Farmacêutica, São Paulo, Brazil

Optimization of the hydrolysis biotechnological process of bovine meat

Hidrolisados de carne bovina são preparados visando a obtenção de pequenos peptídeos ou aminoácidos livres para incorporação em dietas para pessoas em condições fisiológicas especiais. O objetivo do presente é a otimização do processo biotecnológico de hidrólise da proteína da carne bovina pela bromelina. A otimização é feita em base de tratamentos estatísticos dos resultados experimentais para se desenvolver os modelos. A finalidade é elaborar um produto conservado para utilização em dietas. Existe efeito de interação entre o valor de pH e a temperatura nas atividades sobre a caseína da bromelina isolada e naquela presente no suco de abacaxi Ananas comosus L.. A enzima presente no suco \"in natura\" apresenta atividade sobre a caseína superior a bromelina isolada e purificada. Os efeitos do tipo de enzima e da temperatura simultaneamente não afetam a solubilidade alcançada pelas proteínas da carne bovina hidrolisadas com bromelina. Hidrolisados de carne bovina inoculados com esporos de Bacillus stearothermophilus FS 1518 a valor de pH 4,5 não apresentaram sobreviventes mesmo aos 30 segundos de tratamento térmico. Os valores do tempo de redução decimal (D) de esporos de Bacillus stearothermophilus foram de 0,57 min (pH 5,6) e de 0,96 min (pH 6,6); os valores da resistência do microrganismo a diferentes temperaturas (Z) foram de 6,3 °C (pH 5,6) e de 5,9 °C (pH 6,6). O modelo matemático para a atividade enzimática de bromelina de suco de abacaxi é: ^y = 171,63 +13,13 x1 + 18,25 x2 + 18,35 x1.x2 - 25,59x12 - 53,45 x22 A superfície de resposta é do tipo paraboloide elíptica. O valor de pH interfere mais sobre a atividade que a temperatura e o ponto estacionário de máximo indicado pelo modelo é 66,8° e valor de pH 6,4. O modelo matemático para a concentração de sólidos solúveis de carne é: ^ y = 7,13 - 1,02 x1 + 0,81 x2 + 0,45 x1.x2 - 0,42 x12 - 1,52 x22 A superfície de resposta é do tipo paraboloide elíptica. O ponto estacionário de máximo para concentração de sólidos solúveis, indicado pelo modelo é 89,5° e valor de pH 7,1. As condições ótimas indicadas pelo modelo para a atividade enzimática de bromelina de suco de abacaxi atendem a condições satisfatórias de teores de sólidos solúveis. As condições ótimas do processo biotecnológico de hidrólise da carne bovina indicadas pelo acoplamento dos modelos é : temperatura = 66,8 °C, valor de pH = 6,4, atividade enzimática = 175,94 ug/ml.min e concentração de sólidos solúveis = 7,6 g/100g.The protein hydrolyzates production has the aim of preparation of small peptides or amino acids for its use in dietetic foods or with special purposes. The objectives of the research consist in establishing the optimization of the hydrolytic process of bovine meat by bromelain (statistics and mathematical models). The purpose of the study is the development of a preserved product to be used in diets. There is an interaction effect of pH and temperature on enzymic activity over casein by bromelain isolated or from ananas Ananas comosus juice. The bromelain from ananas juice has more activity then the isolated one. The effects of enzyme and temperature together do not affect the solubility of hydrolysed meat proteins. Meat hydrolysates, pH 4,5, inoculated with spores of Bacillus stearothermophilus FS 1518 did not show survivers after 30 sec of treatment. The values of thermal death time (D) were 0,57 min (pH 5,6) and 0,96 min (pH 6,6) and, the Z value 6,3 (pH 5,6) and 5,9 (pH 6,6). The mathematical model for the enzymic activity of bromelain from ananas juice is: ^ = 171,63 +13,13 x1 + 18,25 x2 + 18,35 x1.x2 - 25,59x12 - 53,45 x22 The surface response is paraboloid elipcal. The stationary maximum point indicated by the model is 66,8 °C and pH 6 ,4. The mathematical model for the soluble solids of meat proteins is: ^y = 7,13 - 1,02 x1 + 0,81 x2 + 0,45 x1.x2 - 0,42 x12 - 1,52 x22 The surface response is paraboloid elipcal. The stationary maximum point indicated by the model is 89,5 °C and pH 7,1. The optimum conditions indicated by the enzymic activity model satisfies the soluble solids contents of meat proteins. The optimum conditions of the biotechnological process of hydrolysis of bovine meat are: temperature = 66,8 °C, pH = 6,4, enzymic activity = 175,94 ug/ml.min and soluble solids contents = 7,6 g/100g

Hydrolysed beef - obtain biotechnology

A produção de hidrolisados protéicos visam três propósitos distintos: modificar as propriedades funcionais das proteínas; preparação de pequenos peptídeos ou aminoácidos para uso em dietéticos ou com finalidades especiais e, ainda, como agentes flavorizantes. Os objetivos da pesquisa consistiram em estabelecer as condições de processamento para obtenção de hidrolisados protéicos de carne bovina: estudo da ação enzimática da papaína, da tripsina e da protease microbiana, isoladas e em mistura; determinação do material solubilizado; do grau de hidrólise nas condições pré-estabelecidas e, de algumas propriedades funcionais como viscosidade e capacidade de emulsificação e, ainda, identificação e caracterização das substâncias resultantes da hidrólise. A finalidade do estudo é a elaboração de um preparado formulado para utilização em alimentação enteral. A porção da carne conhecida no mercado pelo nome de \"patinho\" foi submetida a tratamento prévio para retirada de gordura visível e aponevroses e, moída. Utilizou-se a papaína, a tripsina e a protease microbiana, isoladas e em mistura (papaína : tripsina : protease microbiana, 2: 1: 2), previamente submetidas a determinação de atividade. Preparou-se uma suspensão a 10% de proteína e a valor de pH = 7,0, aqueceu-se a 50-60 °C e após a estabilização da temperatura, acrescentou-se as enzimas na proporção 1:100 de proteína. O tratamento com a mistura de enzimas promove enriquecimento do solúvel em aminoácidos essenciais. Com a papaína ocorre o inverso. O teor de aminoácidos livres existentes na carne é baixo. Em apenas 30 minutos de tratamento enzimático na média a concentração eleva-se em 5,7 vezes. Durante a hidrólise ocorre um aumento na concentração de aminoácidos livres. O aminoácido liberado em maior teor em todos tratamentos foi a arginina. O triptofano foi detectado entre os livres e os teores de fenilalanina sempre estiveram abaixo do valor proposto pela FAO. As análises eletroforéticas revelaram a progressão da hidrólise mostrando as diferentes manchas de pesos moleculares cada vez menores. O hidrolisado é um produto de alto teor de oligopeptídeos solúveis e de aminoácidos livres, isento de contaminação microbiana. Durante o transcorrer do processo hidrolítico há uma variação constante nas características do solúvel e na sua composição aminoacídica. Procedeu-se à hidrólise sob agitação durante 3 horas. Após inativação térmica e filtração determinou-se a concentração de sólidos solúveis; a avaliação do peso molecular dos peptídeos solúveis; o fracionamento por cromatografia em camada delgada e, a análise quantitativa dos aminoácidos. Ainda foram feitas medidas de viscosidade e caracterização do fluido. O produto hidrolisado seco, acondicionado em sacos plásticos, foi analisado com relação a composição química, capacidade de emulsificação de sua proteína e perfil de aminoácidos. A eficiência do ataque das enzimas sobre as proteínas da carne bovina deu-se na seguinte ordem: mistura de enzimas, seguida da papaína e da tripsina e finalmente da protease microbiana segundo os parâmetros solubilidade e grau de hidrólise. Passados 120 minutos de hidrólise nas condições de trabalho os valores de graus Brix, sólidos solúveis e grau de hidrólise mantiveram-se inalterados. Na faixa de velocidades angulares ensaiadas o hidrolisado protéico comportou-se como um fluido não-Newtoniano, pseudoplástico. A viscosidade do hidrolisado é de 1,7 a 36,0 poise a 30 °C e 2,4 a 52,7 poise a 60 °C. Os valores máximos para a viscosidade são alcançados aos 90 minutos de hidrólise. Conforme cresce a concentração de proteína solúvel, aumenta a capacidade de emulsificação de óleo de soja em agua, acarretando uma diminuição do diâmetro dos glóbulos de gordura.The protein hydrolyzates production has three different aims: to modify the funcional properties of the proteins; the preparation of small peptides or amino acids for its use in dietetic foods or with special purposes and, also as flavoring agents. The objectives of the research consist in establishing the processing conditions in order to obtain the meat protein hydrolyzates: the study of the enzymatic action of papain, trypsin and of microbial protease, separated or in a blend; determination of the solubilized material; the degree of hydrolysis in previously established conditions, and of some functional properties such as viscosity and emulsifying capacity and, finally the identification and characterization of the resulting substances from the hydrolysis. The purpose of the study is the development of a product to be used in enteral nutrition. The cut of meat locally called patinho\" was subject to previous handling in order to eliminate visible fat and aponeurosis, and ground. The papain, the trypsin and the microbial protease were used, separated or in a blend, previously subject to the determination of its activity. A 10 % protein solution was prepared with pH = 7.0, then heated at 50 - 60 °C and when the temperature was leveled, the enzymes were added to a proportion of 1:100 of protein. Then we proceeded to the hydrolysis under agitation for 3 hours. After thermic inactivation and filtration, the soluble solids concentration was determined, the molecular weight of the soluble peptides was estimated, then fractioning through thin layer chromatography and the amino acids quantity analysis. Viscosity measurement and fluid characterization were also established. The dry hydrolyzate product was stored in plastic bags and was analyzed according to chemical composition and emulsifying capacity of its protein. The effect of the enzyme action on the bovine meat protein was observed in sequence: blending of enzymes, followed by papain and trypsin and finally of the microbial protease according to solubility and degree of hydrolysis. After 120 minutes of hydrolysis under experimental conditions, the Brix degrees, soluble solids and degree of hydrolysis remained unchanged. In the angular velocity range tested the protein hydrolyzate presented a non-Newtonian, pseudoplastic behavior. The viscosity of the hydrolyzate is 1,7 - 36,0 poise at 30 °C and 2,4 - 52,7 poise at 60 °C. The maximum values of viscosity were reached at 90 minutes of hydrolysis. The increase of soluble protein concentration, increases the emulsifying capacity of soybean oil in water, bringing an a lowering of fat globules diameter. The treatment with the enzyme blend promotes an enrichment of the soluble in essential amino acids. The opposite occurs with papain. The ammount of free amino acids exhisting in meat is Low. After only 30 minutes of enzymatic treatment the ammount increases 5.7 times on average. During the hydrolysis the concentration of free amino acids grows. The most commonly found amino acids in all treatments was arginine. The tryptophan was found among the free and the phenylalanin ammounts were always bellow the FAOs proposed parameters. The electrophoretic analysis revealed the progress of hydrolysis, showing the different bands of molecular weights smaller every time. The hydrolyzate is a product of high soluble oligopeptides and free amino acids, free of microbiological contamination. During the hydrolytic process, there is a constant variation in characteristics of the soluble and its amino acidic composition

Hydrolysed beef - obtain biotechnology

A produção de hidrolisados protéicos visam três propósitos distintos: modificar as propriedades funcionais das proteínas; preparação de pequenos peptídeos ou aminoácidos para uso em dietéticos ou com finalidades especiais e, ainda, como agentes flavorizantes. Os objetivos da pesquisa consistiram em estabelecer as condições de processamento para obtenção de hidrolisados protéicos de carne bovina: estudo da ação enzimática da papaína, da tripsina e da protease microbiana, isoladas e em mistura; determinação do material solubilizado; do grau de hidrólise nas condições pré-estabelecidas e, de algumas propriedades funcionais como viscosidade e capacidade de emulsificação e, ainda, identificação e caracterização das substâncias resultantes da hidrólise. A finalidade do estudo é a elaboração de um preparado formulado para utilização em alimentação enteral. A porção da carne conhecida no mercado pelo nome de \"patinho\" foi submetida a tratamento prévio para retirada de gordura visível e aponevroses e, moída. Utilizou-se a papaína, a tripsina e a protease microbiana, isoladas e em mistura (papaína : tripsina : protease microbiana, 2: 1: 2), previamente submetidas a determinação de atividade. Preparou-se uma suspensão a 10% de proteína e a valor de pH = 7,0, aqueceu-se a 50-60 °C e após a estabilização da temperatura, acrescentou-se as enzimas na proporção 1:100 de proteína. O tratamento com a mistura de enzimas promove enriquecimento do solúvel em aminoácidos essenciais. Com a papaína ocorre o inverso. O teor de aminoácidos livres existentes na carne é baixo. Em apenas 30 minutos de tratamento enzimático na média a concentração eleva-se em 5,7 vezes. Durante a hidrólise ocorre um aumento na concentração de aminoácidos livres. O aminoácido liberado em maior teor em todos tratamentos foi a arginina. O triptofano foi detectado entre os livres e os teores de fenilalanina sempre estiveram abaixo do valor proposto pela FAO. As análises eletroforéticas revelaram a progressão da hidrólise mostrando as diferentes manchas de pesos moleculares cada vez menores. O hidrolisado é um produto de alto teor de oligopeptídeos solúveis e de aminoácidos livres, isento de contaminação microbiana. Durante o transcorrer do processo hidrolítico há uma variação constante nas características do solúvel e na sua composição aminoacídica. Procedeu-se à hidrólise sob agitação durante 3 horas. Após inativação térmica e filtração determinou-se a concentração de sólidos solúveis; a avaliação do peso molecular dos peptídeos solúveis; o fracionamento por cromatografia em camada delgada e, a análise quantitativa dos aminoácidos. Ainda foram feitas medidas de viscosidade e caracterização do fluido. O produto hidrolisado seco, acondicionado em sacos plásticos, foi analisado com relação a composição química, capacidade de emulsificação de sua proteína e perfil de aminoácidos. A eficiência do ataque das enzimas sobre as proteínas da carne bovina deu-se na seguinte ordem: mistura de enzimas, seguida da papaína e da tripsina e finalmente da protease microbiana segundo os parâmetros solubilidade e grau de hidrólise. Passados 120 minutos de hidrólise nas condições de trabalho os valores de graus Brix, sólidos solúveis e grau de hidrólise mantiveram-se inalterados. Na faixa de velocidades angulares ensaiadas o hidrolisado protéico comportou-se como um fluido não-Newtoniano, pseudoplástico. A viscosidade do hidrolisado é de 1,7 a 36,0 poise a 30 °C e 2,4 a 52,7 poise a 60 °C. Os valores máximos para a viscosidade são alcançados aos 90 minutos de hidrólise. Conforme cresce a concentração de proteína solúvel, aumenta a capacidade de emulsificação de óleo de soja em agua, acarretando uma diminuição do diâmetro dos glóbulos de gordura.The protein hydrolyzates production has three different aims: to modify the funcional properties of the proteins; the preparation of small peptides or amino acids for its use in dietetic foods or with special purposes and, also as flavoring agents. The objectives of the research consist in establishing the processing conditions in order to obtain the meat protein hydrolyzates: the study of the enzymatic action of papain, trypsin and of microbial protease, separated or in a blend; determination of the solubilized material; the degree of hydrolysis in previously established conditions, and of some functional properties such as viscosity and emulsifying capacity and, finally the identification and characterization of the resulting substances from the hydrolysis. The purpose of the study is the development of a product to be used in enteral nutrition. The cut of meat locally called patinho\" was subject to previous handling in order to eliminate visible fat and aponeurosis, and ground. The papain, the trypsin and the microbial protease were used, separated or in a blend, previously subject to the determination of its activity. A 10 % protein solution was prepared with pH = 7.0, then heated at 50 - 60 °C and when the temperature was leveled, the enzymes were added to a proportion of 1:100 of protein. Then we proceeded to the hydrolysis under agitation for 3 hours. After thermic inactivation and filtration, the soluble solids concentration was determined, the molecular weight of the soluble peptides was estimated, then fractioning through thin layer chromatography and the amino acids quantity analysis. Viscosity measurement and fluid characterization were also established. The dry hydrolyzate product was stored in plastic bags and was analyzed according to chemical composition and emulsifying capacity of its protein. The effect of the enzyme action on the bovine meat protein was observed in sequence: blending of enzymes, followed by papain and trypsin and finally of the microbial protease according to solubility and degree of hydrolysis. After 120 minutes of hydrolysis under experimental conditions, the Brix degrees, soluble solids and degree of hydrolysis remained unchanged. In the angular velocity range tested the protein hydrolyzate presented a non-Newtonian, pseudoplastic behavior. The viscosity of the hydrolyzate is 1,7 - 36,0 poise at 30 °C and 2,4 - 52,7 poise at 60 °C. The maximum values of viscosity were reached at 90 minutes of hydrolysis. The increase of soluble protein concentration, increases the emulsifying capacity of soybean oil in water, bringing an a lowering of fat globules diameter. The treatment with the enzyme blend promotes an enrichment of the soluble in essential amino acids. The opposite occurs with papain. The ammount of free amino acids exhisting in meat is Low. After only 30 minutes of enzymatic treatment the ammount increases 5.7 times on average. During the hydrolysis the concentration of free amino acids grows. The most commonly found amino acids in all treatments was arginine. The tryptophan was found among the free and the phenylalanin ammounts were always bellow the FAOs proposed parameters. The electrophoretic analysis revealed the progress of hydrolysis, showing the different bands of molecular weights smaller every time. The hydrolyzate is a product of high soluble oligopeptides and free amino acids, free of microbiological contamination. During the hydrolytic process, there is a constant variation in characteristics of the soluble and its amino acidic composition

Optimization of the hydrolysis biotechnological process of bovine meat

Hidrolisados de carne bovina são preparados visando a obtenção de pequenos peptídeos ou aminoácidos livres para incorporação em dietas para pessoas em condições fisiológicas especiais. O objetivo do presente é a otimização do processo biotecnológico de hidrólise da proteína da carne bovina pela bromelina. A otimização é feita em base de tratamentos estatísticos dos resultados experimentais para se desenvolver os modelos. A finalidade é elaborar um produto conservado para utilização em dietas. Existe efeito de interação entre o valor de pH e a temperatura nas atividades sobre a caseína da bromelina isolada e naquela presente no suco de abacaxi Ananas comosus L.. A enzima presente no suco \"in natura\" apresenta atividade sobre a caseína superior a bromelina isolada e purificada. Os efeitos do tipo de enzima e da temperatura simultaneamente não afetam a solubilidade alcançada pelas proteínas da carne bovina hidrolisadas com bromelina. Hidrolisados de carne bovina inoculados com esporos de Bacillus stearothermophilus FS 1518 a valor de pH 4,5 não apresentaram sobreviventes mesmo aos 30 segundos de tratamento térmico. Os valores do tempo de redução decimal (D) de esporos de Bacillus stearothermophilus foram de 0,57 min (pH 5,6) e de 0,96 min (pH 6,6); os valores da resistência do microrganismo a diferentes temperaturas (Z) foram de 6,3 °C (pH 5,6) e de 5,9 °C (pH 6,6). O modelo matemático para a atividade enzimática de bromelina de suco de abacaxi é: ^y = 171,63 +13,13 x1 + 18,25 x2 + 18,35 x1.x2 - 25,59x12 - 53,45 x22 A superfície de resposta é do tipo paraboloide elíptica. O valor de pH interfere mais sobre a atividade que a temperatura e o ponto estacionário de máximo indicado pelo modelo é 66,8° e valor de pH 6,4. O modelo matemático para a concentração de sólidos solúveis de carne é: ^ y = 7,13 - 1,02 x1 + 0,81 x2 + 0,45 x1.x2 - 0,42 x12 - 1,52 x22 A superfície de resposta é do tipo paraboloide elíptica. O ponto estacionário de máximo para concentração de sólidos solúveis, indicado pelo modelo é 89,5° e valor de pH 7,1. As condições ótimas indicadas pelo modelo para a atividade enzimática de bromelina de suco de abacaxi atendem a condições satisfatórias de teores de sólidos solúveis. As condições ótimas do processo biotecnológico de hidrólise da carne bovina indicadas pelo acoplamento dos modelos é : temperatura = 66,8 °C, valor de pH = 6,4, atividade enzimática = 175,94 ug/ml.min e concentração de sólidos solúveis = 7,6 g/100g.The protein hydrolyzates production has the aim of preparation of small peptides or amino acids for its use in dietetic foods or with special purposes. The objectives of the research consist in establishing the optimization of the hydrolytic process of bovine meat by bromelain (statistics and mathematical models). The purpose of the study is the development of a preserved product to be used in diets. There is an interaction effect of pH and temperature on enzymic activity over casein by bromelain isolated or from ananas Ananas comosus juice. The bromelain from ananas juice has more activity then the isolated one. The effects of enzyme and temperature together do not affect the solubility of hydrolysed meat proteins. Meat hydrolysates, pH 4,5, inoculated with spores of Bacillus stearothermophilus FS 1518 did not show survivers after 30 sec of treatment. The values of thermal death time (D) were 0,57 min (pH 5,6) and 0,96 min (pH 6,6) and, the Z value 6,3 (pH 5,6) and 5,9 (pH 6,6). The mathematical model for the enzymic activity of bromelain from ananas juice is: ^ = 171,63 +13,13 x1 + 18,25 x2 + 18,35 x1.x2 - 25,59x12 - 53,45 x22 The surface response is paraboloid elipcal. The stationary maximum point indicated by the model is 66,8 °C and pH 6 ,4. The mathematical model for the soluble solids of meat proteins is: ^y = 7,13 - 1,02 x1 + 0,81 x2 + 0,45 x1.x2 - 0,42 x12 - 1,52 x22 The surface response is paraboloid elipcal. The stationary maximum point indicated by the model is 89,5 °C and pH 7,1. The optimum conditions indicated by the enzymic activity model satisfies the soluble solids contents of meat proteins. The optimum conditions of the biotechnological process of hydrolysis of bovine meat are: temperature = 66,8 °C, pH = 6,4, enzymic activity = 175,94 ug/ml.min and soluble solids contents = 7,6 g/100g

Effect of inulin as prebiotic and synbiotic interactions between probiotics to improve fermented milk firmness

Inulin behaved as a prebiotic to improve firmness of skim milk fermented by (a) pure cultures of Lactobacillus acidophilus (La), Lactobacillus rhamnosus (Lr), Lactobacillus bulgaricus (Lb) and Bifidobacterium lactis (Bl), (b) binary co-cultures of them with Streptococcus thermophilus (St), or (c) a cocktail containing all them. Inulin addition to co-cultures and cocktail enhanced products firmness, either after 1 day (D1) or 7 days (D7) of cold storage, likely due to the increase in microbial growth induced by metabolic interactions among lactic acid bacteria and partial inulin metabolization. Co-culture firmness did in fact range from 0.33 N without inulin (St-Lb) after D1 and 0.55 N with inulin (St-Lr) after D7. Also cocktail cultures exhibited high values of firmness, ranging, as an average, from 0.43 N (D1) to 0.46 N (D7), which suggests that they could have been potentiated by the reciprocal synergistic effects of microorganisms in complex mixture. (C) 2011 Elsevier Ltd. All rights reserved.FAPESPCAPES, Brazi

Growth, organic acids profile and sugar metabolism of Bifidobacterium lactis in co-culture with Streptococcus thermophilus: the inulin effect

The organic acids profile, sugar metabolism and biomass growth of Streptococcus thermophilus (St) and Bifidobacterium lactis (BI) have been studied in pure cultures or binary co-culture (St-BI) in skim milk either containing 40 mg/g of inulin or not. With inulin, the time required by St. BI and St-BI to complete fermentation (i.e., when the pH reached 4.5) was about 14, 8 and 49% shorter than without inulin, respectively. This prebiotic also enhanced the levels of lactic and acetic acids and volatile compounds, showing a positive synbiotic effect between pre- and probiotics. In particular, the St-BI co-culture showed final concentrations of both microorganisms about 15 and 38% higher than in their respective pure cultures, thus highlighting a clear synergistic effect between these microorganisms due to mutual interactions. In addition, the well-known bifidogenic effect of inulin was confirmed. (c) 2012 Elsevier Ltd. All rights reserved.FAPESP (Sao Paulo State Research Foundation)Sao Paulo State Research Foundation (FAPESP)CAPES (Coordination of Improvement of Higher Education)CAPES (Coordination of Improvement of Higher Education

Effect of inulin on growth and acidification performance of different probiotic bacteria in co-cultures and mixed culture with Streptococcus thermophilus

Inulin was used as a prebiotic to improve the quality and consistency of skim milk fermented by Lactobacillus acidophilus (La), Lactobacillus rhamnosus (Lr), Lactobacillus bulgaricus (Lb) and Bifidobacterium lactis (BI) with Streptococcus thermophilus (St), either in binary co-cultures or in cocktail containing all microorganisms. We compared, either in the presence of 40 mg inulin g(-1) or not, the results of the maximum acidification rate (V(max)) and the times to reach it (t(max)), to reach pH 5.0 (t(PH5.0)) and to complete the fermentation (t(f)). Post-acidification, lactic acid formation and cell counts were also compared after either 1 day (D1) or 7 days of storage at 4 degrees C (N). In co-culture, inulin addition to the milk increased V(max), decreased t(max) and t(f), favored post-acidification and exerted a bifidogenic effect. S. thermophilus proved to stimulate the metabolism of the other lactic bacteria and enhanced the product features. After D7, a significant prebiotic effect of inulin was observed in all co-cultures. Either after D1 or D7, the enumerations of Lr and BI in mixed culture markedly decreased compared to their respective co-cultures because of greater competition for the same substrates. (C) 2008 Elsevier Ltd. All rights reserved