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Advisor(s)
Abstract(s)
O objetivo do presente estudo, foi avaliar a atividade antibacteriana dos extratos orgânico e aquoso de múkua e mulala. Para tal, foi utilizada uma metodologia modificada a partir de Vuyst, Callewaert & Pol (1996), utilizando como indicadores Pseudomonas aeruginosa, Salmonella Enteritidis, Staphylococcus aureus, Listeria monocytogenes e Escherichia coli. O extrato orgânico de mulala demonstrou ter efeito inibitório em P. aeruginosa, S. Enteritidis e S. aureus e não evidenciou nenhum efeito inibitório sobre L. monocytogenes e E. coli. No caso do extrato aquoso de múkua, observou-se um efeito inibitório em P. aeruginosa, S. Enteritidis e E. coli, não tendo sido registado efeito inibitório em S. aureus e L. monocytogenes. Posteriormente, realizou-se um ensaio experimental de aplicação dos extratos de múkua e mulala no fabrico de um preparado de carne tendo-se utilizado como modelo almôndegas. Para avaliar o efeito antimicrobiano sobre a microbiota da carne, adicionou-se 5%, de extrato de múkua e 1,5% de extrato de mulala. As almôndegas foram embaladas em atmosfera protetora e em aerobiose sendo conservadas a 4 ˚C durante 22 dias. Efetuaram-se contagens de microrganismos aeróbios totais a 30 ˚C, Brochothrix thermosphacta, bactérias ácido lácticas, Enterobacteriaceae e Staphylococcus coagulase-negativa ao longo do período de armazenamento (0, 4, 8, 12, 18 e 22 dias). Nas almôndegas adicionadas de 5% de múkua observou-se um maior efeito inibitório para todos os grupos de microrganismos estudados, sendo maior nas Enterobacteriaceae, Staphylococcus coagulase-negativa e B. thermosphacta. Realizou-se um segundo ensaio com a aplicação do extrato de 1% de múkua em salsichas embaladas em atmosfera protetora, conservadas a 7 ˚C durante 30 dias. Efetuaram-se contagens de microrganismos aeróbios totais a 30 ºC, Enterobacteriaceae e bactérias ácido lácticas ao longo do período de armazenamento (0, 5, 10, 20 e 30 dias). Os extratos vegetais utilizados, mostraram ser efetivos na inibição dos microrganismos patogénicos e de deterioração estudados, tendo-se revelado o extrato aquoso com adição de 5% de múkua o melhor candidato como aditivo natural a utilizar em produtos cárneos. Os resultados evidenciaram que a adição de múkua aos preparados de carne durante o armazenamento reduziu o pH do produto, o que favorece a inibição da multiplicação bacteriana. Os resultados demonstraram que a cor não foi influenciado significativamnete P>(0,05) pelos diferentes tipos de embalagem (aerobiose e atmosfera protetora) a que foram sujeitos os preparados de carne durante os dias de armazenamento. Nas salsichas adicionadas de 1% de múkua observou-se um efeito inibitório nas Enterobacteriaceae no dia 20 mas de modo geral não ocorreu qualquer inibição da microbiota presente.
ABSTRACT - The aim of this study was to evaluate the antibacterial activity of organic and aqueous extracts múkuaand mulala. Therefore, a modified method of Vuyst, Callewaert Pol (1996), was employed to test their inhibitory effect using Pseudomonas aeruginosa, Salmonella Enteritidis, Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli as indicators. The organic extract of mulala demonstrated an inhibitory effect on P. aeruginosa, S. Enteritidis and S. aureus but did not shown any inhibitory effect on L. monocytogenes and E. coli. In the case of the aqueous extract of múkuawas shown an inhibitory effect on P. aeruginosa, S. Enteritidis and E. coli but no effect on S. aureus and L. monocytogenes. In the case of the aqueous extract of múkua, an inhibitory effect was observed in P. aeruginosa, S. Enteritidis and E. coli; no inhibitory effect was observed on S aureus and L. monocytogenes. Subsequently, an experimental test of mukua and mulala extracts application was carried out in the manufacture of a prepared meat product using meatballs as an model. To evaluate the antibacterial effect on the meat microbe added 5% of extract múkua and 1,5 % extract mulala was added. The almondegas were packed in a protected atmosphere and aerobiose being conserved at 4º C during 22 days. The total microorganism aerobic at 30 ° C, Brochothrix thermosphacta, lactic acid bacteria, Enterobacteriaceae and S. coagulase-negative counts were performed, during the storage period (0, 4, 8, 12, 18 and 22 days). A strong inhibitory effect for all groups of microorganisms studied were observed in 5% múkua meatballs, mainly on Enterobacteriaceae, coagulase-negative staphylococci and Brochothrix thermosphacta. A second experimental application with 1% múkua extract in sausages packed in a protected atmosphere and stored at 7 °C for 30 days was assessed. The total microorganism aerobic at 30 °C, Enterobacteriaceae and lactic acid bacteria counts were evaluated throughout the storage period (0, 5, 10, 20 and 30 days). In the meatballs with 5% múkua was observed an inhibitory effect on microbiota development, which may be considered a good candidate as natural preservative. The results showed that addition of múkua to the meat pre-cooked during storage reduced the pH of the product, increasing the inhibition of bacterium multiplication. The results showed that the color was not signicantly influenced P> 0, 05 by the different types of aerobic packaging and protetive atmosphere to which the meat preparations were subjected during storage days. In the added sausages with 1% mukua an inhibitory effect was observed on Enterobacteriaceae at day 20, but generally no inhibition occurred in the present microbiota.
ABSTRACT - The aim of this study was to evaluate the antibacterial activity of organic and aqueous extracts múkuaand mulala. Therefore, a modified method of Vuyst, Callewaert Pol (1996), was employed to test their inhibitory effect using Pseudomonas aeruginosa, Salmonella Enteritidis, Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli as indicators. The organic extract of mulala demonstrated an inhibitory effect on P. aeruginosa, S. Enteritidis and S. aureus but did not shown any inhibitory effect on L. monocytogenes and E. coli. In the case of the aqueous extract of múkuawas shown an inhibitory effect on P. aeruginosa, S. Enteritidis and E. coli but no effect on S. aureus and L. monocytogenes. In the case of the aqueous extract of múkua, an inhibitory effect was observed in P. aeruginosa, S. Enteritidis and E. coli; no inhibitory effect was observed on S aureus and L. monocytogenes. Subsequently, an experimental test of mukua and mulala extracts application was carried out in the manufacture of a prepared meat product using meatballs as an model. To evaluate the antibacterial effect on the meat microbe added 5% of extract múkua and 1,5 % extract mulala was added. The almondegas were packed in a protected atmosphere and aerobiose being conserved at 4º C during 22 days. The total microorganism aerobic at 30 ° C, Brochothrix thermosphacta, lactic acid bacteria, Enterobacteriaceae and S. coagulase-negative counts were performed, during the storage period (0, 4, 8, 12, 18 and 22 days). A strong inhibitory effect for all groups of microorganisms studied were observed in 5% múkua meatballs, mainly on Enterobacteriaceae, coagulase-negative staphylococci and Brochothrix thermosphacta. A second experimental application with 1% múkua extract in sausages packed in a protected atmosphere and stored at 7 °C for 30 days was assessed. The total microorganism aerobic at 30 °C, Enterobacteriaceae and lactic acid bacteria counts were evaluated throughout the storage period (0, 5, 10, 20 and 30 days). In the meatballs with 5% múkua was observed an inhibitory effect on microbiota development, which may be considered a good candidate as natural preservative. The results showed that addition of múkua to the meat pre-cooked during storage reduced the pH of the product, increasing the inhibition of bacterium multiplication. The results showed that the color was not signicantly influenced P> 0, 05 by the different types of aerobic packaging and protetive atmosphere to which the meat preparations were subjected during storage days. In the added sausages with 1% mukua an inhibitory effect was observed on Enterobacteriaceae at day 20, but generally no inhibition occurred in the present microbiota.
Description
Dissertação de Mestrado em Segurança Alimentar
Keywords
Adansonia digitata Euclea natalensis atividade antibacteriana conservante natural antibacterial activity natural preservatives
Pedagogical Context
Citation
Valente, M.A.S.Q. (2017). Avaliação da atividade antibacteriana de Adansonia digitata L. e Euclea natalensis A.DC : sua potencial aplicação num produto cárneo. Dissertação de mestrado. Universidade de Lisboa, Faculdade de Medicina Veterinária, Lisboa.
Publisher
Universidade de Lisboa, Faculdade de Medicina Veterinária