Characterization and application of a biosurfactant isolated from Candida utilis in salad dressings.

This study aimed at characterizing a biosurfactant from Candida utilis, and use it in the preparation of salad dressings. The biosurfactant was produced in mineral medium supplemented with 6% glucose and 6% waste frying canola oil. The crude biosurfactant was then tested for stability in different conditions of pH, salt concentration, heating time and temperature. The critical micelle dilution, chemical composition, and structural analysis were determined. The compound was resistant to extreme conditions and presented stable surface tension and emulsification activity in alkaline pH and was characterized as a carbohydrate-lipid-protein complex showing the best formulation and consistency at 0.7% (w/v) with guar gum indicating potential applicability in food emulsions.

Influence of carvacrol and thymol on the physiological attributes, enterotoxin production and surface characteristics of Staphylococcus aureus strains isolated from foods.

This study evaluated the influence of the phenolic compounds carvacrol (CAR) and thymol (THY) on some physiological characteristics and on the modulation of the secretion of some staphylococcal virulence factors, that is, coagulase and enterotoxin. This study also investigated possible mechanisms for the establishment of the anti-staphylococcal activity of these compounds. Sublethal concentrations (0.3 and 0.15 µL/mL) of CAR and THY inhibited the activity of the enzymes coagulase and lipase and led to a decrease in salt tolerance. At the tested sublethal concentrations, both CAR and THY led to a total suppression of enterotoxin production. The loss of a 260-nm-absorbing material and an efflux of potassium ions occurred immediately after the addition of CAR and THY at 0.6 and 1.2 µL/mL and increased up to 120 min of exposure. Electron microscopy of cells exposed to CAR and THY (0.6 µL/mL) revealed that individual cells appeared to be deformed, with projections of cellular material. The observations of leakage of cellular material and an altered cell surface suggest that gross damage to a cell's cytoplasmic membrane, which results in a disruption in protein secretion, could be responsible for the anti-staphylococcal properties of CAR and THY.

Aproveitamento de soro lácteo na formulação de bebidas com frutas e hortaliças / The use of whey in the formulation of beverages with fruits and vegetables

O uso do soro lácteo como complemento na formulação de alimentos visando ao seu aproveitamento é uma alternativa para a obtenção de novos produtos. Neste trabalho, desenvolveram-se bebidas à base de soro oriundo de queijo coalho tipo A com frutas e hortaliças. Na formulação das bebidas, utilizaram-se diferentes proporções entre soro lácteo, frutas e hortaliças, com adição de 10% de açúcar. Seis bebidas foram formuladas e submetidas a um teste de preferência, e as três primeiras colocadas foram submetidas a um teste de aceitação sensorial. As três preferidas foram as bebidas sabor graviola, morango e goiaba. A bebida sabor graviola obteve aceitação com as melhores notas nos atributos sensoriais cor, sabor, aparência e qualidade global, seguida pela formulação de sabor morango, mas sem diferença significativa (P>0,05). A bebida sabor goiaba teve o diferencial no atributo odor e superou as bebidas sabor graviola e morango (P<0,05). Conclui-se que é viável a elaboração de bebidas à base de soro de queijo coalho com frutas.(AU)

The use of whey as complement in food formulation aiming it's an alternative for the attainment of new products. The aim of this work was developed a type A curd cheese whey derived drink with fruits and vegetables. On drink's formulation was used different ratios of whey, fruits and vegetables, with 10% of sugar. Six drinks were formulated and submited to a preference test. The three best drinks were submitted to a acceptance test. The three best drinks were graviola, strawberry and guava flavours. The graviola one had the greater acceptability with best grades in color's sensory attributes, flavor, appearance and overall quality, following the strawberry flavor, but without significant difference (P<0,05). The guava dink had it's differential on scent character, overcoming the graviola and strawberry drinks (P<0,05). In conclusion we can say that whey-based drink with fruits is viable.(AU)

Aproveitamento de soro lácteo na formulação de bebidas com frutas e hortaliças / The use of whey in the formulation of beverages with fruits and vegetables

O uso do soro lácteo como complemento na formulação de alimentos visando ao seu aproveitamento é uma alternativa para a obtenção de novos produtos. Neste trabalho, desenvolveram-se bebidas à base de soro oriundo de queijo coalho tipo A com frutas e hortaliças. Na formulação das bebidas, utilizaram-se diferentes proporções entre soro lácteo, frutas e hortaliças, com adição de 10% de açúcar. Seis bebidas foram formuladas e submetidas a um teste de preferência, e as três primeiras colocadas foram submetidas a um teste de aceitação sensorial. As três preferidas foram as bebidas sabor graviola, morango e goiaba. A bebida sabor graviola obteve aceitação com as melhores notas nos atributos sensoriais cor, sabor, aparência e qualidade global, seguida pela formulação de sabor morango, mas sem diferença significativa (P>0,05). A bebida sabor goiaba teve o diferencial no atributo odor e superou as bebidas sabor graviola e morango (P<0,05). Conclui-se que é viável a elaboração de bebidas à base de soro de queijo coalho com frutas.

The use of whey as complement in food formulation aiming it's an alternative for the attainment of new products. The aim of this work was developed a type A curd cheese whey derived drink with fruits and vegetables. On drink's formulation was used different ratios of whey, fruits and vegetables, with 10% of sugar. Six drinks were formulated and submited to a preference test. The three best drinks were submitted to a acceptance test. The three best drinks were graviola, strawberry and guava flavours. The graviola one had the greater acceptability with best grades in color's sensory attributes, flavor, appearance and overall quality, following the strawberry flavor, but without significant difference (P<0,05). The guava dink had it's differential on scent character, overcoming the graviola and strawberry drinks (P<0,05). In conclusion we can say that whey-based drink with fruits is viable.

Influence of carvacrol and thymol on the physiological attributes, enterotoxin production and surface characteristics of Staphylococcus aureus strains isolated from foods

This study evaluated the influence of the phenolic compounds carvacrol (CAR) and thymol (THY) on some physiological characteristics and on the modulation of the secretion of some staphylococcal virulence factors, that is, coagulase and enterotoxin. This study also investigated possible mechanisms for the establishment of the anti-staphylococcal activity of these compounds. Sublethal concentrations (0.3 and 0.15 µL/mL) of CAR and THY inhibited the activity of the enzymes coagulase and lipase and led to a decrease in salt tolerance. At the tested sublethal concentrations, both CAR and THY led to a total suppression of enterotoxin production. The loss of a 260-nm-absorbing material and an efflux of potassium ions occurred immediately after the addition of CAR and THY at 0.6 and 1.2 µL/mL and increased up to 120 min of exposure. Electron microscopy of cells exposed to CAR and THY (0.6 µL/mL) revealed that individual cells appeared to be deformed, with projections of cellular material. The observations of leakage of cellular material and an altered cell surface suggest that gross damage to a cell's cytoplasmic membrane, which results in a disruption in protein secretion, could be responsible for the anti-staphylococcal properties of CAR and THY.

Influence of carvacrol and thymol on the physiological attributes, enterotoxin production and surface characteristics of Staphylococcus aureus strains isolated from foods

This study evaluated the influence of the phenolic compounds carvacrol (CAR) and thymol (THY) on some physiological characteristics and on the modulation of the secretion of some staphylococcal virulence factors, that is, coagulase and enterotoxin. This study also investigated possible mechanisms for the establishment of the anti-staphylococcal activity of these compounds. Sublethal concentrations (0.3 and 0.15 µL/mL) of CAR and THY inhibited the activity of the enzymes coagulase and lipase and led to a decrease in salt tolerance. At the tested sublethal concentrations, both CAR and THY led to a total suppression of enterotoxin production. The loss of a 260-nm-absorbing material and an efflux of potassium ions occurred immediately after the addition of CAR and THY at 0.6 and 1.2 µL/mL and increased up to 120 min of exposure. Electron microscopy of cells exposed to CAR and THY (0.6 µL/mL) revealed that individual cells appeared to be deformed, with projections of cellular material. The observations of leakage of cellular material and an altered cell surface suggest that gross damage to a cell's cytoplasmic membrane, which results in a disruption in protein secretion, could be responsible for the anti-staphylococcal properties of CAR and THY.(AU)

Aproveitamento de soro de queijo para produção de iogurte probiótico / The use of cheese whey for probiotic yogurt production

Desenvolveu-se um iogurte natural aproveitando o soro de queijo de coalho, avaliando diferentes processos de pasteurização e concentração de leite em pó. Os iogurtes submetidos a 90ºC/5min nas concentrações de 8 por cento e 10 por cento de leite em pó não apresentaram diferenças entre si (P>0,05) quanto à aceitação sensorial. Os produtos foram caracterizados como integral, atenderam às exigências de proteínas e forneceram mais de 15 por cento do requisito diário recomendado de cálcio para crianças de um a 10 anos, satisfazendo as exigências de cálcio. Em ambas as formulações, o pH decresceu de aproximadamente 4,6 para 4,2 e a acidez aumentou de 0,7g a 1,0g de ácido láctico/100g do produto durante 28 dias de armazenamento. Não houve contaminação por Staphilococcus aureus, coliformes fecais, bolores e leveduras. A contagem de bactérias láticas variou de 5,6x10(9) a 8,0x10(8)UFC/g durante a vida de prateleira, sugerindo a promoção de efeitos benéficos por este alimento probiótico. Concluiu-se que a utilização do soro para a produção de iogurte é uma alternativa viável ao agregar valor econômico, nutricional e funcional ao subproduto.

The objective of this work was to develop a natural yogurt utilizing the resultant whey of a "coalho" cheese production, assaying different processes of pasteurization and powdered milk concentrations. The yogurt submitted to 90ºC/5min with 8 and 10 percent of powdered milk achieved the highest grade on sensorial analysis, with no significant difference (P>0,05). Products were characterized as integral, attended the request for protein, and supplied over 15 percent of the daily feed intake of calcium for children aged 1 to 10, characterizing it as calcium enriched. In both formulations, the pH decreased from 4.6 to 4.2 approximately and the acidity increased from 0.7g to 1.0g lactic acid/100g of product during 28 days of storage. There was no contamination by S. aureus, fecal coliforms, molds and yeasts. The counting of lactic bacteria varied from 5.6x10(9) to 8.0x10(8)CFU/g during shelf life, suggesting the promotion benefits from this probiotic product. It was concluded that whey utilization for yogurt production is a viable alternative to increase economic, nutritional, and functional value.

Aproveitamento de soro de queijo para produção de iogurte probiótico / The use of cheese whey for probiotic yogurt production

Desenvolveu-se um iogurte natural aproveitando o soro de queijo de coalho, avaliando diferentes processos de pasteurização e concentração de leite em pó. Os iogurtes submetidos a 90ºC/5min nas concentrações de 8 por cento e 10 por cento de leite em pó não apresentaram diferenças entre si (P>0,05) quanto à aceitação sensorial. Os produtos foram caracterizados como integral, atenderam às exigências de proteínas e forneceram mais de 15 por cento do requisito diário recomendado de cálcio para crianças de um a 10 anos, satisfazendo as exigências de cálcio. Em ambas as formulações, o pH decresceu de aproximadamente 4,6 para 4,2 e a acidez aumentou de 0,7g a 1,0g de ácido láctico/100g do produto durante 28 dias de armazenamento. Não houve contaminação por Staphilococcus aureus, coliformes fecais, bolores e leveduras. A contagem de bactérias láticas variou de 5,6x10(9) a 8,0x10(8)UFC/g durante a vida de prateleira, sugerindo a promoção de efeitos benéficos por este alimento probiótico. Concluiu-se que a utilização do soro para a produção de iogurte é uma alternativa viável ao agregar valor econômico, nutricional e funcional ao subproduto.(AU)

The objective of this work was to develop a natural yogurt utilizing the resultant whey of a "coalho" cheese production, assaying different processes of pasteurization and powdered milk concentrations. The yogurt submitted to 90ºC/5min with 8 and 10 percent of powdered milk achieved the highest grade on sensorial analysis, with no significant difference (P>0,05). Products were characterized as integral, attended the request for protein, and supplied over 15 percent of the daily feed intake of calcium for children aged 1 to 10, characterizing it as calcium enriched. In both formulations, the pH decreased from 4.6 to 4.2 approximately and the acidity increased from 0.7g to 1.0g lactic acid/100g of product during 28 days of storage. There was no contamination by S. aureus, fecal coliforms, molds and yeasts. The counting of lactic bacteria varied from 5.6x10(9) to 8.0x10(8)CFU/g during shelf life, suggesting the promotion benefits from this probiotic product. It was concluded that whey utilization for yogurt production is a viable alternative to increase economic, nutritional, and functional value.(AU)

Ocorrência de oocistos de Cryptosporidium spp. em águas superficiais na região metropolitana de Recife-PE / Occurrence of Cryptosporidium spp. oocysts in surface water from Recife Metropolitan area, Brazil

The occurrence of Cryptosporidium spp. in superficial waters at the Metropolitan Region of Recife, PE, was studied. Raw and treated water were analyzed by filtration of the samples on a membrane (47mm, 3µm) under negative pressure, by the direct immunofluorescence assay (IFA), and by the 4'6'-diamidino-2-phenylindole (DAPI) method. The samples were analyzed during drought (September to February) and raining (March to August) seasons. Oocysts were not found in treated water. Cryptosporidium spp. oocysts were found in non-treated water by IFA/DAPI technique in 40% (2/5) of the locations and in 5% (3/60) of the samples investigated, with the number varying from 16 oocysts/l to 40/l, in dry and raining seasons, respectively. This is the first report of Cryptosporidium spp. in surface water in the state of Pernambuco, Northeast of Brazil.

Ocorrência de oocistos de Cryptosporidium spp. em águas superficiais na região metropolitana de Recife-PE / Occurrence of Cryptosporidium spp. oocysts in surface water from Recife Metropolitan area, Brazil

The occurrence of Cryptosporidium spp. in superficial waters at the Metropolitan Region of Recife, PE, was studied. Raw and treated water were analyzed by filtration of the samples on a membrane (47mm, 3µm) under negative pressure, by the direct immunofluorescence assay (IFA), and by the 4'6'-diamidino-2-phenylindole (DAPI) method. The samples were analyzed during drought (September to February) and raining (March to August) seasons. Oocysts were not found in treated water. Cryptosporidium spp. oocysts were found in non-treated water by IFA/DAPI technique in 40% (2/5) of the locations and in 5% (3/60) of the samples investigated, with the number varying from 16 oocysts/l to 40/l, in dry and raining seasons, respectively. This is the first report of Cryptosporidium spp. in surface water in the state of Pernambuco, Northeast of Brazil. (AU)

Effectiveness of Cryptosporidium spp. oocysts detection and enumeration methods in water and milk samples

Cryptosporidium spp. oocyst recovery in water and milk samples was evaluated. Samples were inoculated with a suspension of 1.2×10(7) Cryptosporidium spp. oocysts and submitted to centrifugal flotation, using different solutions (sucrose, NaCl, MgSO4, ZnSO4, AlSO4, NH4SO4 40 percent and NH4SO4 80 percent). Centrifugation of the samples was carried out in two stages for concentration using two methods that differed in the order in which the saturated solutions were used, namely only in the first stage of method I and only in the second stage of method II. Oocyst identification was performed using the Kinyoun and Koster histochemical staining techniques. Samples analyzed by method I showed different degree of oocyst recovery, namely 10.9 percent with NaCl and 42.5 percent with MgSO4 in water and milk samples, while those samples analyzed by method II showed 10.6 percent with NaCl and 5.3 percent with sucrose in water and milk, respectively. Histochemical staining methods have no influence on the degree of oocysts recovery. The efficiency of Cryptosporidium spp. oocysts recovery methods depends on the nature and composition of the sample and on the methodology used for oocyst concentration.

Avaliou-se a recuperação de oocistos de Cryptosporidium spp. em amostras de água e leite. As amostras foram contaminadas experimentalmente com uma suspensão de 1,2×10(7) oocistos de Cryptosporidium spp. e concentradas por centrífugo-flutuação para comparação entre diferentes substâncias (sacarose, NaCl, MgSO4, ZnSO4, AlSO4, NH4SO4 40 por cento e NH4SO4 80 por cento). A centrifugação das amostras foi realizada em duas etapas para concentração utilizando-se dois métodos, diferentes pela ordem do uso das soluções saturadas no procedimento, na primeira etapa de concentração do método I, e na segunda etapa, do método II. A identificação do oocisto foi realizada mediante as técnicas de coloração histoquímica Kinyoun e Koster modificado. O grau de recuperação de oocistos foi 10,9 por cento com NaCl e 42,5 por cento com MgSO4 nas amostras de água e leite, respectivamente (método I), e de 10,6 por cento com NaCl e 5,3 por cento com sacarose nas amostras de água e leite, respectivamente (método II). Os métodos de coloração histoquímica não influenciaram nos resultados. A eficácia dos métodos de recuperação de oocistos de Cryptosporidium spp. depende da natureza e composição da amostra e da metodologia usada para a concentração dos oocistos na amostra.

Effectiveness of Cryptosporidium spp. oocysts detection and enumeration methods in water and milk samples / Eficácia de métodos de detecção e enumeração de oocistos de Cryptosporidium spp. em amostras de água e leite

Cryptosporidium spp. oocyst recovery in water and milk samples was evaluated. Samples were inoculated with a suspension of 1.2×107 Cryptosporidium spp. oocysts and submitted to centrifugal flotation, using different solutions (sucrose, NaCl, MgSO4, ZnSO4, AlSO4, NH4SO4 40% and NH4SO4 80%). Centrifugation of the samples was carried out in two stages for concentration using two methods that differed in the order in which the saturated solutions were used, namely only in the first stage of method I and only in the second stage of method II. Oocyst identification was performed using the Kinyoun and Koster histochemical staining techniques. Samples analyzed by method I showed different degree of oocyst recovery, namely 10.9% with NaCl and 42.5% with MgSO4 in water and milk samples, while those samples analyzed by method II showed 10.6% with NaCl and 5.3% with sucrose in water and milk, respectively. Histochemical staining methods have no influence on the degree of oocysts recovery. The efficiency of Cryptosporidium spp. oocysts recovery methods depends on the nature and composition of the sample and on the methodology used for oocyst concentration.(AU)

Avaliou-se a recuperação de oocistos de Cryptosporidium spp. em amostras de água e leite. As amostras foram contaminadas experimentalmente com uma suspensão de 1,2×107 oocistos de Cryptosporidium spp. e concentradas por centrífugo-flutuação para comparação entre diferentes substâncias (sacarose, NaCl, MgSO4, ZnSO4, AlSO4, NH4SO4 40% e NH4SO4 80%). A centrifugação das amostras foi realizada em duas etapas para concentração utilizando-se dois métodos, diferentes pela ordem do uso das soluções saturadas no procedimento, na primeira etapa de concentração do método I, e na segunda etapa, do método II. A identificação do oocisto foi realizada mediante as técnicas de coloração histoquímica Kinyoun e Koster modificado. O grau de recuperação de oocistos foi 10,9% com NaCl e 42,5% com MgSO4 nas amostras de água e leite, respectivamente (método I), e de 10,6% com NaCl e 5,3% com sacarose nas amostras de água e leite, respectivamente (método II). Os métodos de coloração histoquímica não influenciaram nos resultados. A eficácia dos métodos de recuperação de oocistos de Cryptosporidium spp. depende da natureza e composição da amostra e da metodologia usada para a concentração dos oocistos na amostra.(AU)

Perfil de sensibilidade antimicrobiana in vitro de staphylococcus coagulase positivos isolados de leite de vacas com mastite no agreste do estado de pernambuco / Profile of in vitro antimicrobial susceptibility of coagulase-positive staphylococcus isolated from cows' milk with mastitis in the rural area of the state of pernambuco

RESUMO A mastite, inflamação da glândula mamária, é uma das principais doenças da bovinocultura de leite tendo como principal agente infeccioso bactérias do gênero Staphylococcus spp. que comumente apresentam resistência aos antibióticos utilizados no tratamento da mastite. Desta forma, objetivouse com este estudo traçar o perfil de sensibilidade antimicrobiana de 59 cepas de estafilococos coagulase positivo, isolados de amostras de leite de vaca com mastite. Os testes de sensibilidade antimicrobiana foram realizados através da técnica de difusão com discos para 13 antibióticos, verificando-se que os mais eficazes foram a vancomicina com 100% de sensibilidade e a norfloxacina com 96%. O menos eficaz foi a penicilina com 20% de sensibilidade. Em alguns municípios estudados as cepas de estafilococos apresentaram resistência múltipla para 6 a 9 antibióticos simultaneamente. Conclui-se que a análise da sensibilidade antimicrobiana in vitro deve ser considerada pelos proprietários antes da tomada de decisões para a escolha do tratamento adequado para reduzir perdas na produção de leite e em programas de controle da doença em questão.

ABSTRACT Mastitis, inflammation of the mammary gland, is one of the main diseases of milk cattle, having as the main infectious agent the Staphylococcus spp. bacteria, which commonly presents resistance to the antibiotics used in the treatment of mastitis. For this reason, this study was aimed at drawing the profile of anti-microbial sensibility of 59 strains of coagulase-positive staphylococcus, isolated from samples of cow milk with mastitis. The tests of anti-microbial sensibility were accomplished through a diffusion technique with disks for 13 antibiotics, it being verified that the most effective were vancomycin with 100% of susceptibility and norfloxacin with 96%. The least effective was penicillin with 20% of susceptibility. In some of the studied coutries the staphylococcus strains presented multiple resistance to from 6 to 9 antibiotics simultaneously. The conclusion is that the analysis of the anti-microbial susceptibility in vitro should be considered by the proprietors before taking decisions about the choice of the appropriate treatment in order to reduce losses in the production of milk and in control programs of the disease in question.

Características microbiológicas da carne de caprinos submetidos a diferentes formas de manejo / Characteristics microbiological of the meat of goats submitted to peculiar forms of management

A manipulação da carcaça no abate propicia a proliferação de microorganismos. A produção de carne caprina que atenda aos requisitos de segurança microbiológica agrega valor ao produto, além de traduzir a eficiência do processamento em todas as suas etapas. O objetivo deste trabalho foi observar se o perfil microbiológico da carne caprina dos animais pesquisados encontra-se de acordo com padrões propostos na Resolução - RDC n. 12, de 2 de janeiro de 2001, que define o Regulamento Técnico sobre Padrões Microbiológicos para Alimentos. Determinou-se o pH, a atividade de água e o número mais provável de coliformes totais e fecais, Salmonella sp e Staphylococcus coagulase positiva. Amostras constituídas pelo conjunto de músculos que formam a perna do caprino (total de 24 animais) foram analisadas. Os resultados demonstraram que, de um modo geral, amostras desse estudo atenderam aos requisitos de segurança microbiológica da referida RDC, com exceção pra um dos grupos pesquisados (C - 30), que apresentou uma concentração de Coliformes fecais de 2,1 x 10 , valor este acima do estabelecido pela legislação vigente que é de 10. Este artigo serve de interesse para cientistas de alimentos que pesquisam a carne, e microbiologistas que trabalham com saúde pública e se interessam pela segurança das carnes em geral e da carne caprina em particular.

Características microbiológicas da carne de caprinos submetidos a diferentes formas de manejo / Characteristics microbiological of the meat of goats submitted to peculiar forms of management

A manipulação da carcaça no abate propicia a proliferação de microorganismos. A produção de carne caprina que atenda aos requisitos de segurança microbiológica agrega valor ao produto, além de traduzir a eficiência do processamento em todas as suas etapas. O objetivo deste trabalho foi observar se o perfil microbiológico da carne caprina dos animais pesquisados encontra-se de acordo com padrões propostos na Resolução - RDC n. 12, de 2 de janeiro de 2001, que define o Regulamento Técnico sobre Padrões Microbiológicos para Alimentos. Determinou-se o pH, a atividade de água e o número mais provável de coliformes totais e fecais, Salmonella sp e Staphylococcus coagulase positiva. Amostras constituídas pelo conjunto de músculos que formam a perna do caprino (total de 24 animais) foram analisadas. Os resultados demonstraram que, de um modo geral, amostras desse estudo atenderam aos requisitos de segurança microbiológica da referida RDC, com exceção pra um dos grupos pesquisados (C - 30), que apresentou uma concentração de Coliformes fecais de 2,1 x 10 , valor este acima do estabelecido pela legislação vigente que é de 10. Este artigo serve de interesse para cientistas de alimentos que pesquisam a carne, e microbiologistas que trabalham com saúde pública e se interessam pela segurança das carnes em geral e da carne caprina em particular.(AU)

The manipulation of the carcass in abates it propitiates the proliferation of I microrganismos. The production of goat meat that takes care of to the requirements of microbiological security adds value to the product, besides translating the efficiency of the processing in all its stages. The objective of this work was to observe if the microbiological profile of the goat meat of the searched animals in accordance with meets the standards considered in the Resolution? RDC nº 12, of 2 of January of 2001, that it defines the Regulation Technician on Microbiological Standards for Foods. PH was deter· mined, the activity of water and the most likely number of total and fecals coliformes, Salmonella sp and positive Staphylococcus coagulase. Samples consisting of the set of muscles that form the leg of the goat one (total of 24 animals) had been analyzed. (...)(AU)

Functional properties of yam bean (Pachyrhizus erosus) starch.

The study was carried out in order to determine and establish the functional characters of starch extracted from yam bean (Pachyrhizus erosus (L) Urban) compared with cassava starch. Yam bean is a tropical tuber legume easily grown and holds a great potential as a new source of starch. Yam bean starch shows functional properties which are peculiar to those of most starch root crops. Gelatinization temperature (53-63 degrees C) and the pasting temperature (64.5 degrees C) are less than those of cereal starch, however, the swelling power is high (54.4 g gel/g dried starch). Yam bean starch paste presents a high viscosity profile, high retrogradation tendency and low stability on cooking. The functional properties of yam bean starch, similar to those of cassava starch, allows yam bean to be used as a potential new source of starch.

Production and characterization of a thermostable glucoamylase from Streptosporangium sp. endophyte of maize leaves.

Thermostable amylolytic enzymes are currently investigated to improve industrial processes of starch degradation. Streptosporangium sp. an endophytic actinomycete isolated from leaves of maize (Zea mays L.) showed glucoamylase production, using starch-Czapek medium, and the highest rate was obtained in the initial growth phase, after incubation for 24 h at pH 8.0. Maximum glucoamylase activity (158 U mg(-1) protein) was obtained at pH 4.5 and 70 degrees C. The isolated enzyme exhibited thermostable properties as indicated by retention of 100% of residual activity at 70 degrees C for 30 min with total inhibition at 100 degrees C. Extracellular enzyme from Streptosporangium sp. was purified by fractionated precipitation with ammonium sulphate. After 60% saturation produced 421 U mg(-1) protein, and yield was 74% with purification 2.7 fold. The enzyme produced by Streptosporangium sp. has potential for industrial applications.

Changes in Saccharomyces cerevisiae development induced by magnetic fields.

Saccharomyces cerevisiae cultures exposed to 110 mT and 220 mT steady magnetic fields (SMF) were studied to observe eventual induced growth alterations and changes in metabolic activity. Cell mass (biomass) growth was evaluated by light spectrometry, and metabolic alterations were estimated on the basis of the CO2 pressure produced and by the culture media pH changes, measured at the beginning and the end of the observation. The yeast strain DAUFPE-1012, cultivated in a nonaerated liquid agar Sabouraud glucose medium, was exposed to SMF generated by NdFeBr magnets. Results showed alterations induced by 220 mT SMF as an increment in cell proliferation (1.84%) and an increased CO2 production (36.1%) as compared to control groups. Furthermore, the initial-to-final pH difference in 220 mT SMF exposed cultures was higher than the 110 mT SMF and the control values. The whole acidification and the rise in CO2 production observed after 220 mT SMF exposure did not correspond to the biomass growth values, as compared to the other cultures, and was apparently provoked by a enhancement in the cellular metabolic rate. This technique becomes very promising for future biotechnological applications in fermentative processes.

Production and characterization of a thermostable alpha-amylase from Nocardiopsis sp. endophyte of yam bean.

Thermostable amylolytic enzymes have been currently investigated to improve industrial processes of starch degradation. Studies on production of alpha-amylase by Nocardiopsis sp., an endophytic actinomycete isolated from yam bean (Pachyrhizus erosus L. Urban), showed that higher enzyme levels were obtained at the end of the logarithmic growth phase after incubation for 72 h at pH 8.6. Maximum activity of alpha-amylase was obtained at pH 5.0 and 70 degrees C. The isolated enzyme exhibited thermostable properties as indicated by retention of 100% of residual activity at 70 degrees C, and 50% of residual activity at 90 degrees C for 10 min. Extracellular enzyme from Nocardiopsis sp. was purified by fractional precipitation with ammonium sulphate. After 60% saturation produced 1130 U mg-1 protein and yield was 28% with purification 2.7-fold. The enzyme produced by Nocardiopsis sp. has potential for industrial applications.

Avaliaçäo microbiológica de refeiçöes servidas por empresas aéreas nacionais / Microbiological evaluation of food services in aviation

Avaliou-se a qualidade microbiológica de refeiçöes servidas por empresas aéreas nacionais, sendo constituídas por pratos à base de pescado, carnes e produtos cárneos, produtos lácteos e sobremesas, além da água utilizada nos locais de processamento dos alimentos e das mäos dos manipuladores. Foram determinadas contagens de bactérias mesófilas, de coliformes totais e E. coli e contagem e identificaçäo de S. aureus. Dos resultados obtidos constatou-se que todas as amostras de alimentos apresentavam contagens para bactérias mesófilas e coliformes totais abaixo dos limites máximos estabelecidos pelos padröes internacionais (RIBEIRO, 1974; ICMSF, 1982). A presença de E. coli em três amostras de queijo ricota, duas com valores 6,5 x 100 UFC/g e uma com valores maiores que 3,0 x 10.000 UFC/g, sendo estes resultados acima do permitido pela legislaçäo brasileira (BRASIL, 1997), demonstram a baixa qualidade do produto artesanal e as precárias condiçöes higiênico-sanitárias durante a produçäo. Verificou-se ausência de S. aureus em 100 por cento das amostras de alimentos analisados. Constatou-se, também, ausência de coliformes totais nas 10 (100 por cento) amostras de água e ausência de E. coli e S. aureus em todas as amostras das mäos dos manipuladores de alimentos. Os resultados encontrados sugerem a existência de condiçöes higiências adequadas durante o processamento e manipulaçäo das refeiçöes oferecidas pelas empresas aéreas nacionais, sendo próprias para consumo.