Differences in muscle dimensional parameters between non-formalin-fixed (freeze-thawed) and formalin-fixed specimen in gorilla (Gorilla gorilla)

摘要

The objective of this work is to show that fresh and minimally processed vegetables sold in selected retail outlets in Durban South Africa may contain unacceptable level of pathogenic microorganisms and that L. monocytogenes ATCC 7644 may be resistant to combinations of sanitizers. Selected vegetables were purchased from three retail outlets in Durban and examined for the presence of aerobic bacteria (AB), aerobic sporeformers (ASF), anaerobic sporeformers (AnSF), S. aureus, and L. monocytogenes using ISO methods. Cucumber was also inoculated with 108 cfu/ml of L. monocytogenes ATCC 7688 and later washed with 200 ppm chlorine, hydrogen peroxide, hot water and combination of hot water and chlorine; and also hot water and hydrogen peroxide. Analysis of variance showed that there was no significant difference between mean values of AB, ASF and AnSF in vegetables from the three retail outlets. The mean values of AB, ASF and AnSF in the sampled vegetables from the retail outlets were of 6.01 log cfu/g, 3.62 log cfu/g and 2.91 log cfu/g, respectively. Presence of S. aureus was noticeably low; however, L. monocytogenes was present in 75% of the samples tested, 200 ppm chlorine was found to be most effective in reducing the level of L. monocytogenes ATCC 7644 although it was found like other sanitizers not to eradicate all the inoculated pathogens. Combination of heat treatment and chemical treatment proved not to be significantly effective when compared to the chemical treatments alone. This research indicated that sampled vegetables constitute public health risk and that sanitizers are not 100% effective as an intervention for produce safety.