The antimicrobial activity of donkey milk was initially scanned against nine microorganisms using agar diffusion assay, and was further investigated via in situ inhibition by monitoring the growth of Salmonella choleraesuis (CGMCC 1.1859) and Shigella dysenteriae (CGMCC 1.1869) in it. The changes of microflora of donkey milk during prolonged storage at 4 and 20 °C were also studied. The results of the agar diffusion showed that S. choleraesuis and S. dysenteriae were the most sensitive strains towards the antimicrobial activity of donkey milk. In situ test revealed that the donkey milk exerted a definite bactericidal activity against S. dysenteriae and the viable counts decreased to below detectable level in a 1-ml sample at 20 °C. In the microbiological flora analysis, initial raw donkey milk contained a low microbial content. At 20 °C, lactic acid bacteria, coliforms and fungi grew well in donkey milk to give a total number of 6.66 log cfu/ml, 5.88 and 2.95, respectively, after 24 h storage. At 4 °C, no significant changes of microflora were observed after 96 h except coliforms which gave an 1 log increase. 相似文献
The aim of this study was to assess the microbial populations causing the spoilage of chilled beef during storage and to evaluate the effect of the use of an antimicrobial packaging for the meat storage. A nisin activated antimicrobial packaging was developed by using a nisin, HCL and EDTA solution and used for the storage of beef cuts at 1 °C. The common spoilage related microbial groups were monitored during the storage of beef in activated and non activated plastic bags by using selective media. The use of the antimicrobial packaging caused an overall significant reduction of viable counts of Gram positive bacteria such as carnobacteria, lactic acid bacteria and Brochotrix thermosphacta whose development was inhibited for at least 11 days of storage compared to the control. Moreover, a 1–3 log cycles reduction of enterobacteria was also registered between 22 and 32 days of storage. The microbiota was assessed at species level by using Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis of 16S rRNA gene of DNA extracted directly from meat and from bulk cells from selective media plates and showed that the species occurring within the targeted microbial groups did not change according to storage conditions. In conclusion, the use of the nisin activated packaging reduced the number of spoilage populations but did not affect the species diversity. Improved antimicrobial packaging is needed, possibly coupled with vacuum storage, to possibly achieve a simultaneous inhibition of more spoilage microbial groups and to preserve the microbiological quality of beef during chilled storage. 相似文献
The effect of dried-ground Urtica dioica L. on microbiological characteristics of Turkish dry-fermented sausage (sucuk) were investigated. Dried-ground Urtica dioica L. was added to sucuk batters by the rate of 0%, 1%, 3% and 5%, and microbiological analysis were made on the 0, 3, 7, 10 and 14 days of ripening period.
According to the results, both the level of Urtica dioica L. and ripening time had a significant effects on the total aerobic mesophylic bacteria, lactic acid bacteria, Micrococcus/Staphylococcus, yeast-mould and Enterobacteriaceae counts (p<0.01). It was determined that the interactions ripening time × the levels of Urtica dioica L. had a significant effects on the counts of total aerobic mesophylic bacteria, lactic acid bacteria, Micrococcus/Staphylococcus, yeast-mould and Enterobacteriaceae (p<0.01). Enterobacteriaceae count were also found to be under the detectable level (<100 cfu/g) in sucuks (in day 14 of ripening) containing 3% and 5% Urtica dioica L. 相似文献