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Microbiological Shelf Life of Pasteurized Milk in Bottle and Pouch

PETRUS, R. R.; LOIOLA, C. G.; OLIVEIRA, C. A. F.
Fonte: WILEY-BLACKWELL PUBLISHING, INC Publicador: WILEY-BLACKWELL PUBLISHING, INC
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
57.1%
Shelf life of pasteurized milk in Brazil ranges from 3 to 8 d, mainly due to poor cold chain conditions that prevail throughout the country and subject the product to repeated and/or severe temperature abuse. This study evaluated the influence of storage temperature on the microbiological stability of homogenized whole pasteurized milk (75 degrees C/15 s) packaged in high-density polyethylene (HDPE) bottle and low-density polyethylene (LDPE) pouch, both monolayer materials pigmented with titanium dioxide (TiO(2)). The storage temperatures investigated were 2, 4, 9, 14, and 16 degrees C. Microbiological evaluation was based on mesophilic and psychrotrophic counts with 7 log CFU/mL and 6 log CFU/mL, respectively, set as upper limits of acceptability for maintaining the quality of milk. The microbiological stability for pasteurized milk packaged in HDPE bottle and stored at 2, 4, 9, 14, and 16 degrees C was estimated at 43, 36, 8, 5, and 3 d, respectively. For milk samples packaged in LDPE pouch, shelf life was estimated at 37, 35, 7, 3, and 2 d, respectively. The determination of Q(10) and z values demonstrated that storage temperature has a greater influence on microbiological shelf life of pasteurized milk packaged in LDPE pouch compared to HDPE bottle. Based on the results of this study...

PCR detection of staphylococcal enterotoxin genes in Staphylococcus aureus strains isolated from raw and pasteurized milk

Rall, V. L. M.; Vieira, F. P.; Rall, R.; Vietis, R. L.; Fernandes, A.; Candeias, J. M. G.; Cardoso, K. F. G.; Araujo, J. P.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 408-413
Português
Relevância na Pesquisa
56.89%
Milk is considered a nutritious food because it contains several important nutrients including proteins and vitamins. Conversely, it can be a vehicle for several pathogenic bacteria such as Staphylococcus aureus. This study aimed to analyze the frequency of genes encoding the staphylococcal enterotoxins (SEs) SEA, SEB, SEC, SED, SEE, SEG, SEH, SEI and SEJ in S. aureus strains isolated from raw or pasteurized bovine milk. S. aureus was found in 38 (70.4%) out of 54 raw milk samples at concentrations of up to 8.9 X 10(5) CFU/ml. This microorganism was present in eight samples of pasteurized milk before the expiration date and in 11 samples analyzed on the expiration date. of the 57 strains studied, 68.4% were positive for one or more genes encoding the enterotoxins, and 12 different genotypes were identified. The gene coding for enterotoxin A, sea, was the most frequent ( 16 strains, 41%), followed by sec (8 strains, 20.5%), sed (5 strains, 12.8%). seb (3 strains. 7.7%) and see (2 strains, 5.1%). Among the genes encoding the other enterotoxins, seg was the most frequently observed (11 strains. 28.2%), followed by sei (10 strains) and seh and sej (3 strains each). With the recent identification of new SEs, the perceived frequency of enterotoxigenic strains has increased. suggesting that the pathogenic potential of staphylococci may be higher than previously thoughts however...

Occurrence of Mycobacterium bovis and non-tuberculous mycobacteria (NTM) in raw and pasteurized milk in the northwestern region of Paraná, Brazil

Sgarioni, Sônia Aparecida; Hirata, Rosario Dominguez Crespo; Hiroyuki Hirata, Mario; Leite, Clarice Queico Fujimura; Prince, Karinaandrade De; Leite, Sergio Roberto De Andrade; Vedovello Filho, Dirceu; Siqueira, Vera Lucia Dias; Caleffi-ferracioli, Katia
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: 707-711
Português
Relevância na Pesquisa
57.06%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Milk is widely consumed in Brazil and can be the vehicle of agent transmission. In this study, was evaluated the occurrence of Mycobacterium bovis and non-tuberculous mycobacteria (NTM) in raw and pasteurized milk consumed in the northwestern region of Paraná, Brazil. Fifty-two milk samples (20 pasteurized and 32 raw) from dairy farms near the municipality of Maringa, Parana State, Brazil were collected. Milk samples were decontaminated using 5% oxalic acid method and cultured on Lowenstein-Jensen and Stonebrink media at 35 °C and 30 °C, with and without 5-10% CO2. Mycobacteria isolates were identified by morphological features, PCR-Restriction Fragment Length Polymorphism Analysis (PCR-PRA) and Mycolic acids analysis. Thirteen (25%) raw and 2 (4%) pasteurized milk samples were positive for acid fast bacilli growth. Nine different species of NTM were isolated (M. nonchromogenicum, M. peregrinum, M. smegmatis, M. neoaurum, M. fortuitum, M. chelonae, M. flavescens, M. kansasii and M. scrofulaceum). M. bovis was not detected. Raw and pasteurized milk may be considered one source for NTM human infection. The paper reinforces the need for intensification of measures in order to avoid the milk contamination and consequently prevent diseases in the south of Brazil.

Efeito do tempo de armazenamento do leite cru e da temperatura de esticagem do leite pasteurizado sobre sua vida de prateleira.; Effects of raw milk storage time and pasteurized milk storage temperature on milk shelflife.

Gustavo Braga Sanvido
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 30/07/2007 Português
Relevância na Pesquisa
67.3%
O objetivo do trabalho foi avaliar o efeito do tempo de armazenamento do leite cru e da temperatura de estocagem do leite pasteurizado sobre sua qualidade físicoquímica, microbiológica e vida de prateleira. Para cada experimento utilizouse 150 litros de leite cru que foram divididos em 3 latões de 50 litros armazenados por 0, 4 ou 7 dias a 5 ± 1ºC antes da pasteurização. Durante o armazenamento refrigerado, amostras de leite cru foram avaliadas quando a presença de resíduos de antibióticos, contagem de células somáticas, pH, acidez, densidade, extrato seco total, gordura, nitrogênio total e solúvel em pH 4,6 e em TCA 24%, coliformes a 3035 ºC e a 45ºC e a contagem dos seguintes microorganismos: aeróbios mesófilos, psicrotróficos, Pseudomonas spp., termodúricos mesófilos e psicrotróficos, esporos mesófilos e psicrotróficos. Após o período de armazenamento refrigerado o leite foi pasteurizado (7275 ºC/1520 segundos), refrigerado (5±1ºC) e envasado em embalagens plásticas de polietileno, as quais foram divididas em dois lotes e estocadas a 5±1ºC ou a 10±1ºC. Durante o armazenamento refrigerado amostras dos leites pasteurizados foram avaliadas para as mesmas características, excetuandose contagem de células somáticas e a presença de resíduos de antibióticos e incluindose os testes de eficiência de pasteurização (peroxidase e fosfatase) e a pesquisa de Salmonela spp. O final da vida de prateleira do leite pasteurizado foi estabelecido como sendo o primeiro dia em que as amostras apresentassem contagem total de microorganismos mesófilos aeróbios superior a 8 x 10 4 UFC/mL. O experimento completo foi repetido três vezes e o delineamento experimental utilizado foi o Splitsplitplot com três fatores. Durante o armazenamento refrigerado do leite cru observouse o aumento significativo da proteólise...

Efeito do armazenamento refrigerado e da microfiltração na qualidade e vida útil do leite pasteurizado; Effect of refrigerated storage and microfiltration in quality and shelf life of pasteurized milk

Veridiana de Carvalho Antunes
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 25/02/2013 Português
Relevância na Pesquisa
57.11%
A extensão da vida de prateleira do leite pasteurizado é um desafio e uma necessidade para a indústria de laticínios. A microfiltração tem sido utilizada para remoção de micro-organismos e aumento da qualidade e vida de prateleira de leite fluido, sendo geralmente realizada em membranas cerâmicas sob o conceito de Pressão Transmembranar Uniforme (PTU). O objetivo desse trabalho foi avaliar o desempenho de um novo tipo de membrana (Isoflux®) capaz de manter o fluxo de permeado constante ao longo do comprimento da membrana e também o efeito do armazenamento refrigerado e da microfiltração na qualidade e vida útil do leite pasteurizado. O desempenho da membrana Isoflux , na microfiltração do leite cru, foi avaliado através da determinação do fluxo de permeado, retenção de células somáticas, microorganismos, gordura e caseína. Em geral, o fluxo da membrana estudada foi baixo, variando de 130 a 200 Kg/h/m2. A retenção de micro-organismos mesófilos e psicrotróficos foi maior que 99%, enquanto a retenção de coliformes foi de 90%, e de 100% para células somáticas. A membrana reteve, em média, 11,2% de caseína e 34,6% de gordura. O efeito do armazenamento refrigerado do leite cru (7 ºC/ 6 dias) e o impacto da microfiltração na microbiota...

Isolation and serological identification of enteropathogenic Escherichia coli in pasteurized milk in Brazil

Silva,Zoraide N da; Cunha,Adriana S da; Lins,Márcia C; Carneiro,Letícia de AM; Almeida,Angela C de F; Queiroz,Mara LP
Fonte: Faculdade de Saúde Pública da Universidade de São Paulo Publicador: Faculdade de Saúde Pública da Universidade de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2001 Português
Relevância na Pesquisa
67.05%
OBJECTIVE: To evaluate the microbiological quality of pasteurized milk commercialized in Rio de Janeiro, Brazil, and determine serologically enteropathogenic Escherichia coli (EPEC) strains in E. coli isolates obtained from milk samples. METHODS: Ninety samples of pasteurized milk -- types B and C -- of three different commercial brands, purchased in supermarkets and bakeries in Rio de Janeiro, were examined. The amount of total and fecal coliform bacteria was estimated using the Most Probable Number technique. Mesophilic, psychrotrophic, and thermoduric microorganism counts were determined by the Standard Plate Count technique. Isolation and identification of E. coli were carried out using conventional physiological tests. Commercial antisera were used for serological characterization of EPEC. RESULTS: The three milk brands analyzed revealed bacterial counts above the regulated values of the Brazilian government. It was found that among 208 strains of E. coli isolated, 46 (22.1%) were serologically classified as EPEC. The most common EPEC serogroup was O55 (15.2%). CONCLUSIONS: Though recent studies on virulence factors indicate that not all strains serologically classified as EPEC are able to attaching/effacing lesion, it is believed that the isolation of EPEC serogroups from pasteurized milk represent a potential risk for children...

Antimicrobial resistance profiles of enterococci isolated from poultry meat and pasteurized milk in Rio de Janeiro, Brazil

Fracalanzza,Suely Aparecida Pimenta; Scheidegger,Erica Miranda Damásio; Santos,Patricia Faria dos; Leite,Paola Cardarelli; Teixeira,Lúcia Martins
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2007 Português
Relevância na Pesquisa
66.76%
The enterococci are important nosocomial pathogens with a remarkable capacity of expressing resistance to several antimicrobial agents. Their ubiquitous nature and resistance to adverse environmental conditions take account for their ability to colonize different habitats and for their potential for easy spreading through the food chain. In the present study we evaluated the distribution of species and antimicrobial susceptibility among enterococcal isolates recovered from food obtained in retail stores in Rio de Janeiro, Brazil. The following species were identified among 167 isolates obtained from poultry meat and 127 from pasteurized milk: Enterococcus faecalis (62.6%), E. casseliflavus (17.3%), E. durans (6.5%), E. gallinarum (3.0%), E. gilvus (2.4%), E. faecium (2.0%), E. hirae (1.4%), and E. sulfureus (1.0%). The overall percentages of antimicrobial resistant isolates were: 31.2 % to tetracycline, 23.8% to erythromycin, 11.3% to streptomycin, 4.3% to chloramphenicol, 3.9% to gentamicin, 1.4% to norfloxacin, 1.1% to imipenem, 0.7% to ciprofloxacin, nitrofurantoin, and penicillin, and 0.4% to ampicillin. Intermediate resistance was detected in frequencies varying from 0.5% for linezolid to 58.2% for erythromycin. None of the isolates showed resistance to glycopeptides. High-level resistance to aminoglycosides was observed in 13.1% of the isolates. Multiresistance was observed in E. faecalis...

Evaluation of the PetrifilmTM and TEMPO® systems and the conventional method for counting microorganisms in pasteurized milk

Cirolini,Andréia; Baseggio,Andressa Mara; Miotto,Marília; Ramos,Roberta Juliano; Cattani,Cristhiane Stecanella de Oliveira; Vieira,Cleide Rosana Werneck
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 Português
Relevância na Pesquisa
56.93%
New microbiological methods have been developed and commercialized, but their performance must be guaranteed. The aim of the present study was to evaluate the PetrifilmTM and TEMPO® systems compared to the conventional method for counting microorganisms in pasteurized milk. A total of 141 samples of pasteurized milk were analyzed by counting mesophilic aerobic, Coliforms at 35 ºC, Coliforms at 45 ºC, and Escherichia coli microorganisms. High correlation was found between the methods for counting Coliforms at 35 ºC, but low correlation was found for counting mesophilic aerobic, Coliforms at 45 ºC, and Escherichia coli. No significant statistical difference was found among the three methods for counting Coliforms at 35 ºC; however, the mean counts of mesophilic aerobic, Coliforms at 45 ºC, and Escherichia coli showed significant statistical difference. PetrifilmTM and TEMPO® systems had satisfactory results for Coliforms at 35 ºC in pasteurized milk but low performance for mesophilic aerobic, Coliforms at 45 ºC and Escherichia coli.

Assessment of the efficiency of SimPlate™ total plate count color indicator (TPC CI) to quantify mesophilic aerobic microorganisms in pasteurized milk

Nero,Luís Augusto; Beloti,Vanerli; Barros,Márcia de Aguiar Ferreira; Santana,Elsa Helena Walter de; Pereira,Mykel Steffani; Gusmão,Viviane Vieira; Moraes,Luciane Bilia de
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2002 Português
Relevância na Pesquisa
56.92%
The SimPlate™ TPC CI system is a rapid method to count mesophilic aerobic microorganisms (MAM) in foods, based on the use of resazurine to indicate bacterial growth. Its efficiency in pasteurized milk was evaluated using 142 pasteurized milk samples (38 type A, 43 type B and 61 type C) collected in Londrina, PR. The standard plating method, using Plate Count Agar (PCA) was used for comparison. The plates of both systems were incubated at 35ºC and read after 24h and 48h. The occurrence of false-positive and false-negative wells and the predominant microorganisms in them were also evaluated. The results were compared by simple correlation and mean variance analyses. The correlation (r) and mean variance values were 0.6811 and 0.7583 for the results obtained after 24h, respectively, and 0.9126 and 0.0842 for the results obtained after 48h, respectively. These results indicate that the performance of the system increases when the plates are incubated for 48h. When the three types of milk were evaluated separately, these values were 0.9285 and 0.0817 for type A milk, 0.9231 and 0.0466 for type B milk and 0.7209 and 0.1082 for type C milk. These results indicate that the better the quality of the milk the better the performance of SimPlate™ TPC CI. False-negative wells...

First isolation of Mycobacterium avium subsp paratuberculosis from commercial pasteurized milk in Argentina

Paolicchi,Fernando; Cirone,Karina; Morsella,Claudia; Gioffré,Andrea
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2012 Português
Relevância na Pesquisa
66.95%
Mycobacterium avium subsp paratuberculosis was isolated from two out of seventy samples (2.86 %) of pasteurized and ultra-pasteurized milk. The isolates were positives to IS900 PCR and showed a C17 RFLP pattern, the most prevalent in Argentina. The present study is the first report of Mycobacterium avium subsp paratuberculosis culture from pasteurized milk in Argentina.

Occurrence of Mycobacterium bovis and non-tuberculous mycobacteria (NTM) in raw and pasteurized milk in the northwestern region of Paraná, Brazil

Sgarioni,Sônia Aparecida; Hirata,Rosario Dominguez Crespo; Hiroyuki Hirata,Mario; Leite,Clarice Queico Fujimura; Prince,KarinaAndrade de; Leite,Sergio Roberto de Andrade; Vedovello Filho,Dirceu; Siqueira,Vera Lucia Dias; Caleffi-Ferracioli,Katiany Rizzie
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 Português
Relevância na Pesquisa
57.06%
Milk is widely consumed in Brazil and can be the vehicle of agent transmission. In this study, was evaluated the occurrence of Mycobacterium bovis and non-tuberculous mycobacteria (NTM) in raw and pasteurized milk consumed in the northwestern region of Paraná, Brazil. Fifty-two milk samples (20 pasteurized and 32 raw) from dairy farms near the municipality of Maringa, Parana State, Brazil were collected. Milk samples were decontaminated using 5% oxalic acid method and cultured on Lowenstein-Jensen and Stonebrink media at 35 °C and 30 °C, with and without 5-10% CO2. Mycobacteria isolates were identified by morphological features, PCR-Restriction Fragment Length Polymorphism Analysis (PCR-PRA) and Mycolic acids analysis. Thirteen (25%) raw and 2 (4%) pasteurized milk samples were positive for acid fast bacilli growth. Nine different species of NTM were isolated (M. nonchromogenicum, M. peregrinum, M. smegmatis, M. neoaurum, M. fortuitum, M. chelonae, M. flavescens, M. kansasii and M. scrofulaceum). M. bovis was not detected. Raw and pasteurized milk may be considered one source for NTM human infection. The paper reinforces the need for intensification of measures in order to avoid the milk contamination and consequently prevent diseases in the south of Brazil.

Inhibition of food-related bacteria by antibacterial substances produced by Pseudomonas sp. strains isolated from pasteurized milk

Rangel,Ana Beatriz Ferreira; Soares,Jean Thiago Alves; Pereira,Mariana Maciel; Peçanha,Bruna Rachel de Britto; Costa,Leonardo Emanuel de Oliveira; Nascimento,Janaína dos Santos
Fonte: Instituto de Tecnologia de Alimentos - ITAL Publicador: Instituto de Tecnologia de Alimentos - ITAL
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 Português
Relevância na Pesquisa
56.81%
In this work, the production of antimicrobial substances by strains of Pseudomonas sp. isolated from pasteurized milk and their potential action against food-related bacteria were investigated. Samples of pasteurized milk were purchased from arbitrarily chosen commercial establishments in the city of Rio de Janeiro, Brazil. Of the four samples analyzed, three presented several typical colonies of Pseudomonas. About 100 colonies were chosen and subjected to biochemical tests for confirmation of their identity. Eighteen strains of the Pseudomonas genus were identified and submitted to tests for the production of antimicrobial substances. Twelve strains (66.7%) were identified as Pseudomonas fluorescens, four (22.2%) as P. aeruginosa, one (5.5%) as P. mendocina and one (5.5%) as P. pseudoalcaligenes. Only two P. fluorescens strains were unable to produce any antimicrobial substance against any of the indicator strains tested. Most of the strains presented a broad spectrum of action, inhibiting reference and food-related strains such as Proteus vulgaris, Proteus mirabilis, Hafnia alvei, Yersinia enterocolitica, Escherichia coli and Salmonella typhi. Five antimicrobial substance-producing strains, which presented the broadest spectrum of action...

Genetic heterogeneity of Escherichia coli isolated from pasteurized milk in State of Paraná, Brazil

Oltramari,Karine; Cardoso,Rosilene Fressati; Patussi,Eliana Valéria; Santos,Adolfo Carlos Barreto; Mikcha,Jane Martha Graton
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 Português
Relevância na Pesquisa
67.07%
Food contamination caused by enteric pathogens is a major cause of diarrheal disease worldwide, resulting in high morbidity and mortality and significant economic losses. Bacteria are important agents of foodborne diseases, particularly diarrheagenic Escherichia coli. The present study assessed the genetic diversity and antimicrobial resistance of E. coli isolates from pasteurized milk processed in 21 dairies in northwestern State of Parana, Brazil. The 95 E. coli isolates were subjected to antimicrobial susceptibility testing according to the recommendations of the Clinical and Laboratory Standards Institute and assessed genotypically by Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR). The highest rate of resistance was observed for cephalothin (55.78%). ERIC-PCR revealed high genetic diversity, clustering the 95 bacterial isolates into 90 different genotypic patterns. These results showed a heterogeneous population of E. coli in milk samples produced in the northwestern region of Paraná and the need for good manufacturing practices throughout the processing of pasteurized milk to reduce the risk of foodborne illnesses.

Genetic heterogeneity of Escherichia coli isolated from pasteurized milk in State of Paraná, Brazil

Oltramari, Karine; Cardoso, Rosilene Fressati; Patussi, Eliana Valeria; Barreto Santos, Adolfo Carlos; Graton Mikcha, Jane Martha
Fonte: Universidade de São Paulo, Conjunto Químicas Publicador: Universidade de São Paulo, Conjunto Químicas
Tipo: Artigo de Revista Científica Formato: 337-343
Português
Relevância na Pesquisa
67.07%
Food contamination caused by enteric pathogens is a major cause of diarrheal disease worldwide, resulting in high morbidity and mortality and significant economic losses. Bacteria are important agents of foodborne diseases, particularly diarrheagenic Escherichia coli. The present study assessed the genetic diversity and antimicrobial resistance of E. coli isolates from pasteurized milk processed in 21 dairies in northwestern State of Parana, Brazil. The 95 E. coli isolates were subjected to antimicrobial susceptibility testing according to the recommendations of the Clinical and Laboratory Standards Institute and assessed genotypically by Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR). The highest rate of resistance was observed for cephalothin (55.78%). ERIC-PCR revealed high genetic diversity, clustering the 95 bacterial isolates into 90 different genotypic patterns. These results showed a heterogeneous population of E. coli in milk samples produced in the northwestern region of Parana and the need for good manufacturing practices throughout the processing of pasteurized milk to reduce the risk of foodborne illnesses.; A contaminação de alimentos por patógenos entéricos é uma das principais causas de doenças diarréicas em todo o mundo...

Frequency of 2,3,5-triphenyltetrazolium chloride (TTC) non-reducing bacteria in pasteurized milk

Beloti,Vanerli; Barros,Márcia A.F.; Freitas,Júlio C. de; Nero,Luís A.; Souza,Juliana A. de; Santana,Elsa H.W.; Franco,Bernadette. D.G.M.
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/1999 Português
Relevância na Pesquisa
66.93%
2,3,5-triphenyltetrazolium chloride (TTC) is a dye largely used for enumeration of microbial colonies in solid culture media, being a key component of the dry rehydratable film system used for microbiological analysis of food. This dye is colorless in the oxidized form and red when reduced by microorganisms, due to formation of formazan. In this study, TTC was added to Plate Count Agar (PCA) for enumeration of microorganisms in thirty four pasteurized milk samples, with the aim to verify the frequency of microorganisms that are unable to reduce TTC. Milk samples were decimally diluted in saline and pour-plated in PCA plus 0.015% TTC. Colonies were counted after 24h and 48 h of incubation at 35oC. From a total of 50,574 colonies, 19,665 (38.88%) did not reduce TTC in 48h. It was observed that 571 (6.36%) colonies that were colorless in 24h became red in 48h. From those that didn't reduce TTC in 48h, 233 were purified and Gram stained. 229 (98.71%) of them were Gram positive cocci and bacilli. The results show that there is a high percentage of microorganisms unable to reduce TTC in pasteurized milk, which cannot be detected by laboratory procedures based on the formation of red colonies.

STUDY OF MODIFICATIONS THAT OCCUR IN PASTEURIZED FROZEN MILK DURING THE STORAGE; ESTUDO DAS MODIFICAÇÕES QUE OCORREM NO LEITE PASTEURIZADO CONGELADO, DURANTE O ARMAZENAMENTO

BENEDET, HONÓRIO DOMINGOS; Universidade Federal de Santa Catarina
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 14/08/2009 Português
Relevância na Pesquisa
56.76%
Pasteurized milk, after freezing at -18°C were stored during twelve weeks with the finality to verify modifications ocurred. Determinations of peroxide, pH, acidity, total counting of mesophyllus, psicrophyllus and acceptability tests were carried out.; Leite pasteurizado e congelado a -18°C foi armazenado durante 12 semanas com a finalidade de verificar as modificações ocorridas. Foram realizadas determinações de peróxidos, pH, acidez, contagem total de mesófilos e psicrófilos, bem como, testada a aceitabilidade. Os resultados obtidos indicam que as alterações ocorridas não foram significativas, indicando que esse procedimento pode prolongar-se por tempo maior.

“COAGULUM” CHEESE ELABORATED FROM A PASTEURIZED AND INOCULATED MILK WITH Streptococcus thermophyllus E Lactobacillus bulgaricus: SENSORIAL AND BIOCHEMICAL ASPECTS; ELABORAÇÃO DE QUEIJO DE COALHO A PARTIR DE LEITE PASTEURIZADO E INOCULADO COM Streptococcus thermophyllus E Lactobacillus bulgaricus: ASPECTOS BIOQUÍMICO E SENSORIAL

LIMA, MARCIA HELENA PORTELA; Núcleo de tecnologia Industrial; TELLES, FRANCISCO JOSÉ SIQUEIRA; Universidade Federal do Ceará; MACEDO, BENEMÁRIA ARAÚJO; Universidade Estadual do Ceará; BENEVIDES, SELENE DAIHA; Universidade Federal do Ceará
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 15/04/2009 Português
Relevância na Pesquisa
56.98%
Coagulum type cheeses made from milk heat-treated (LTLT pasteurization) and inoculated with 1% starter (Streptococcus thermophillus and Lactobacillus bulgaricus) were compared to those cheeses traditionally obtained from raw milk concerning the intensity of cure and acceptability. The cheese ripening was realized at room temperature (29 °C) and in cold chamber (12 °C) during ten days. The cheeses presented approximate ripening rates, however values were slightly higher for those inoculated with lactic ferment and with the ripening done at room temperature. The cheeses were considered equal in a 5% level of significance. It means that it is possible to obtain coagulum cheeses from pasteurized milk with the thermophylic culture used. The sensory tests indicated a preference for those cheeses made from pasteurized/inoculated milk ripened at room temperature.;  Queijos de coalho elaborados a partir de leite tratado termicamente e inoculado a 1% com cultura termofílica (Streptococcus thermophyllus e Lactobacillus bulgaricus) foram comparados com queijos obtidos tradicionalmente. Considerou-se no estudo a intensidade de cura e a aceitabilidade do produto. A maturação foi realizada a temperatura ambiente (29 °C) e em câmara fria (12 °C) durante dez dias. Os queijos apresentaram índices de maturação próximos e valores ligeiramente maiores para aqueles inoculados com fermento lático e maturação a temperatura ambiente. A média de aceitabilidade (ao nível de 5% de significância) evidenciou a possibilidade de obtenção de queijo de coalho a partir de leite pasteurizado e inoculado com S. thermophyllus e L. bulgaricus. As médias atribuídas pelos provadores indicaram certa preferência por este queijo...

STUDY OF PHYSICOCHEMICAL AND MICROBIOLOGICAL QUALITY OF PASTEURIZED MILK IN AN INDUSTRY FROM SANTA CATARINA (BRAZIL); ESTUDO DA QUALIDADE FÍSICO-QUÍMICA E MICROBIOLÓGICA DO LEITE PASTEURIZADO NUMA INDÚSTRIA DE SANTA CATARINA

DE SOUZA, SOLANGE; BENEDET, HONÓRIO DOMINGOS
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 20/08/2009 Português
Relevância na Pesquisa
66.81%
Twenty samples of raw milk were analysed frem different parts of the procesing line: at the packing, storage and expedition. The results of density, crioscopy, fat, inhibitors, preservatives, microorganisms and absence of inhibitors and preservatives. Recontamination occurred in 20% of total pasteurized milk.; Em três pontos da linha de processamento de leite pasteurizado ou seja: na empacotadeira, câmara de estocagem e local de expedição foram coletadas e analisadas no mês de abril de 1987, 20 amostras de leite em termos de densidade, crioscopia, gordura, inibidores, conservantes e microrganismos, observando-se a ausência de inibidores e conservantes e, que ocorreu recontaminação em 20% do total de leite pasteurizado.

Determination of the presence of 10 antimicrobial residues in mexican pasteurized milk

Gutiérrez Tolentino,Rey; Noa Pérez,Mario; Díaz González,Gilberto; Vega y León,Salvador; González López,Magdalena; Prado Flores,Guadalupe
Fonte: ASOCIACIÓN INTERCIENCIA Publicador: ASOCIACIÓN INTERCIENCIA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2005 Português
Relevância na Pesquisa
66.94%
Residues of 9 antimicrobial agents approved in México for veterinary use in dairy cattle (sulfathiazole, sulfamerazine, sulfamethazine, sulfachloropyridazine, sulfamonomethoxine, sulfamethoxazole, nitrofurazone, furaltadone, and furazolidone) and non-approved chloramphenicol residues were studied every two weeks in four commercial brands of Mexican pasteurized milk (A, B, C and D) during one year (n=4×24=96). Drug residues were analyzed by high pressure liquid chromatography HPLC with UV detection. Percentage of positive samples to sulfonamide residues were 47.2% (Milk A), 58.3% (Milk B), 44.7% (Milk C) and 50% (Milk D). Sulfonamide residues ranged between 1.9 and 180µg/kg. sulfathiazole and sulfamerazine were the most common residues found. Only three samples (Milk B) exceeded maximum residue levels established for sulfonamides. Nitrofuran residues were not detected in any milk sample. Illegal Chloramphenicol residues were detected in one milk sample (Milk A) in levels of 27.2µg/kg.

Isolation and serological identification of enteropathogenic Escherichia coli in pasteurized milk in Brazil

Silva,Zoraide N da; Cunha,Adriana S da; Lins,Márcia C; Carneiro,Letícia de AM; Almeida,Angela C de F; Queiroz,Mara LP
Fonte: Faculdade de Saúde Pública da Universidade de São Paulo Publicador: Faculdade de Saúde Pública da Universidade de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2001 Português
Relevância na Pesquisa
67.05%
OBJECTIVE: To evaluate the microbiological quality of pasteurized milk commercialized in Rio de Janeiro, Brazil, and determine serologically enteropathogenic Escherichia coli (EPEC) strains in E. coli isolates obtained from milk samples. METHODS: Ninety samples of pasteurized milk -- types B and C -- of three different commercial brands, purchased in supermarkets and bakeries in Rio de Janeiro, were examined. The amount of total and fecal coliform bacteria was estimated using the Most Probable Number technique. Mesophilic, psychrotrophic, and thermoduric microorganism counts were determined by the Standard Plate Count technique. Isolation and identification of E. coli were carried out using conventional physiological tests. Commercial antisera were used for serological characterization of EPEC. RESULTS: The three milk brands analyzed revealed bacterial counts above the regulated values of the Brazilian government. It was found that among 208 strains of E. coli isolated, 46 (22.1%) were serologically classified as EPEC. The most common EPEC serogroup was O55 (15.2%). CONCLUSIONS: Though recent studies on virulence factors indicate that not all strains serologically classified as EPEC are able to attaching/effacing lesion, it is believed that the isolation of EPEC serogroups from pasteurized milk represent a potential risk for children...