RESUMO

The present study outlines a comprehensive correlation between the natural microbial load, which is predominantly composed of heat-resistant sporous-forming Bacillus, and the changes in the original properties related to the superficial color of vacuum-packaged cooked sausages. For this purpose, microbial growth curves were plotted by stimulating the growth of the natural microbiota in sausage packages at different temperatures. The correlations were investigated during sample incubation by the instrumental evaluation of color and the ropy slime detection on the sausage surface. The entrance of the natural microbiota into the stationary phase (ca. 9.3 log cfu/g) resulted in changes in the superficial color, which was demonstrated by the discoloration of vacuum-packaged cooked sausages. Therefore, it seems to be a suitable borderline for predictive models applied in durability studies that aim to estimate the period in which vacuum-packaged cooked sausages keep their typical superficial color, anticipating product refusal in markets.

Assuntos

RESUMO

In the development of functional probiotic food, the carrier matrices should be carefully selected and optimized to ensure the highest levels of probiotic survival in the symbiotic food along storage. Because milk and honey food matrices are rich in antioxidant substances, the aim of the research was to evaluate their effect in protecting lactobacilli from reactive oxygen species (ROS) generated by the addition of hydrogen peroxide. Viability assays were performed with and without the addition of H2O2, in three different matrices: 0.9% peptone saline, 5% honey, or 12% reconstituted skim milk. The milk matrix provided protection for the Lacticaseibacillus paracasei DTA83 and Lacticaseibacillus rhamnosus DTA76. However, this protective effect was not observed in the survival of Lactobacillus acidophilus La 5. Honey solution did not maintain the viability of probiotic microorganisms exposed to hydrogen peroxide and, on the contrary, caused a significant reduction in the population of L. rhamnosus DTA76 (p < 0.001). Lower membrane lipid peroxidation due to H2O2 exposure was observed in L. acidophilus La 5 and L. rhamnosus DTA76, but this marker showed no relation with viability. It was concluded: (i) lactobacilli from the Lacticaseibacillus genus were the ones that benefited most from the lactic environment; (ii) the absence of the protective effect of honey was possibly due to the presence of Fe2+ which reacts with H2O2 to produce hydroxyl radicals; and (iii) cell viability did not correlate with membrane lipid peroxidation, and it is not a good marker to evaluate this type of damage in cells of different microorganisms.

Assuntos

RESUMO

The aim of this research was to optimize the growth parameters (pH, ethanol tolerance, initial cell concentration and temperature) for Saccharomyces boulardii and its tolerance to in vitro gastrointestinal conditions for probiotic alcoholic beverage development. Placket-Burman screening was used to select only statistically significant variables, and the polynomial mathematical model for yeast growth was obtained by central composite rotatable design. Confirmation experiments to determine the kinetic parameters for yeast growth were carried out by controlling the temperature and pH. Soon after, the survivability of yeast was tested under in vitro conditions mimicking the human upper gastrointestinal transit. S. boulardii had suitable resistance to alcohol and gastrointestinal conditions for probiotic alcoholic beverage development.

RESUMO

ABSTRACT: Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host. The aim of this study was to identify genotypically lactobacilli strains isolated from newborn stools and selecting strain based on probiotic properties (gastrointestinal tolerance, antibiotic susceptibility, inhibition of pathogen biofilm formation, absence of alfa or gamma-blood hemolysis, and lysozyme sensibility) and technological properties of surviving either in ice cream bar or ice-lolly. Reduction of 1.2log cfu ml-1 of the Lactobacillus paracasei strain was observed after exposure through in vitro gastrointestinal conditions. It inhibited biofilms of Escherichia coli, Salmonella Typhimurium and Candida albicans by mechanisms of competition, exclusion and displacement, and was resistant up to 3000μg ml-1 of egg white lysozyme. It presented neither alfa nor gamma-hemolysis or was antibiotic resistant to usual antibiotics for human use. Microbial survivability in ice cream bar or ice-lolly was assessed up to 21 days of storage at -18°C. Viability was maintained in ice cream bar, but there was a reduction of almost 2.0logs in ice-lolly.

RESUMO: Probióticos são microrganismos vivos que, quando administrados em quantidade adequadas, conferem benefícios à saúde do hospedeiro. O objetivo desta pesquisa foi identificar genotipicamente lactobacilos isolados de material fecal de recém-nascidos, assim como selecionar uma cepa com base em suas propriedades probióticas (tolerância às condições gastrointestinais, susceptibilidade à antibióticos, inibição da formação de biofilmes por microrganismos patogênicos, ausência de hemólise alfa ou gama e sensibilidade à lisozima) e tecnológicas de sobrevivência em picolé à base de água ou leite. Houve redução de 1,2log ufc ml-1 do isolado identificado como Lactobacillus paracasei após passagem pelas condições gastrointestinais in vitro. Esta cepa inibiu a formação de biofilmes de Escherichia coli, Salmonella Typhimurium e Candida albicans pelos mecanismos de competição, exclusão e desacoplamento e apresentou resistência até 3000μg ml-1 frente a lisozima de ovo. Entre os aspectos de segurança, a cepa não apresentou hemólise alfa ou gama e não foi resistente a antibióticos comumente ministrados em humanos. A sobrevivência microbiana em picolé a base de água ou leite foi analisada ao longo de 21 dias de estocagem a -18°C. Houve manutenção da viabilidade no produto à base de leite, mas naquele à base de água, ocorreu redução de quase 2,0logs.

RESUMO

ABSTRACT: Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host. The aim of this study was to identify genotypically lactobacilli strains isolated from newborn stools and selecting strain based on probiotic properties (gastrointestinal tolerance, antibiotic susceptibility, inhibition of pathogen biofilm formation, absence of alfa or gamma-blood hemolysis, and lysozyme sensibility) and technological properties of surviving either in ice cream bar or ice-lolly. Reduction of 1.2log cfu ml-1 of the Lactobacillus paracasei strain was observed after exposure through in vitro gastrointestinal conditions. It inhibited biofilms of Escherichia coli, Salmonella Typhimurium and Candida albicans by mechanisms of competition, exclusion and displacement, and was resistant up to 3000g ml-1 of egg white lysozyme. It presented neither alfa nor gamma-hemolysis or was antibiotic resistant to usual antibiotics for human use. Microbial survivability in ice cream bar or ice-lolly was assessed up to 21 days of storage at -18°C. Viability was maintained in ice cream bar, but there was a reduction of almost 2.0logs in ice-lolly.

RESUMO: Probióticos são microrganismos vivos que, quando administrados em quantidade adequadas, conferem benefícios à saúde do hospedeiro. O objetivo desta pesquisa foi identificar genotipicamente lactobacilos isolados de material fecal de recém-nascidos, assim como selecionar uma cepa com base em suas propriedades probióticas (tolerância às condições gastrointestinais, susceptibilidade à antibióticos, inibição da formação de biofilmes por microrganismos patogênicos, ausência de hemólise alfa ou gama e sensibilidade à lisozima) e tecnológicas de sobrevivência em picolé à base de água ou leite. Houve redução de 1,2log ufc ml-1 do isolado identificado como Lactobacillus paracasei após passagem pelas condições gastrointestinais in vitro. Esta cepa inibiu a formação de biofilmes de Escherichia coli, Salmonella Typhimurium e Candida albicans pelos mecanismos de competição, exclusão e desacoplamento e apresentou resistência até 3000g ml-1 frente a lisozima de ovo. Entre os aspectos de segurança, a cepa não apresentou hemólise alfa ou gama e não foi resistente a antibióticos comumente ministrados em humanos. A sobrevivência microbiana em picolé a base de água ou leite foi analisada ao longo de 21 dias de estocagem a -18°C. Houve manutenção da viabilidade no produto à base de leite, mas naquele à base de água, ocorreu redução de quase 2,0logs.

RESUMO

Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host. The aim of this study was to identify genotypically lactobacilli strains isolated from newborn stools and selecting strain based on probiotic properties (gastrointestinal tolerance, antibiotic susceptibility, inhibition of pathogen biofilm formation, absence of alfa or gamma-blood hemolysis, and lysozyme sensibility) and technological properties of surviving either in ice cream bar or ice-lolly. Reduction of 1.2log cfu ml-1 of the Lactobacillus paracasei strain was observed after exposure through in vitro gastrointestinal conditions. It inhibited biofilms of Escherichia coli, Salmonella Typhimurium and Candida albicans by mechanisms of competition, exclusion and displacement, and was resistant up to 3000μg ml-1 of egg white lysozyme. It presented neither alfa nor gamma-hemolysis or was antibiotic resistant to usual antibiotics for human use. Microbial survivability in ice cream bar or ice-lolly was assessed up to 21 days of storage at -18°C. Viability was maintained in ice cream bar, but there was a reduction of almost 2.0logs in ice-lolly.(AU)

Probióticos são microrganismos vivos que, quando administrados em quantidade adequadas, conferem benefícios à saúde do hospedeiro. O objetivo desta pesquisa foi identificar genotipicamente lactobacilos isolados de material fecal de recém-nascidos, assim como selecionar uma cepa com base em suas propriedades probióticas (tolerância às condições gastrointestinais, susceptibilidade à antibióticos, inibição da formação de biofilmes por microrganismos patogênicos, ausência de hemólise alfa ou gama e sensibilidade à lisozima) e tecnológicas de sobrevivência em picolé à base de água ou leite. Houve redução de 1,2log ufc ml-1 do isolado identificado como Lactobacillus paracasei após passagem pelas condições gastrointestinais in vitro. Esta cepa inibiu a formação de biofilmes de Escherichia coli, Salmonella Typhimurium e Candida albicans pelos mecanismos de competição, exclusão e desacoplamento e apresentou resistência até 3000μg ml-1 frente a lisozima de ovo. Entre os aspectos de segurança, a cepa não apresentou hemólise alfa ou gama e não foi resistente a antibióticos comumente ministrados em humanos. A sobrevivência microbiana em picolé a base de água ou leite foi analisada ao longo de 21 dias de estocagem a -18°C. Houve manutenção da viabilidade no produto à base de leite, mas naquele à base de água, ocorreu redução de quase 2,0logs.(AU)

Assuntos

RESUMO

A qualidade da água consumida pela população distrito de Sana, Macaé,RJ foi avaliada por meio de análises microbiológicas para pesquisa de coliformes termotolerantes e totais e bactérias heterotróficas baseando-se na portaria nº518/2004- Ministério da Saúde. A água consumida...

Assuntos