Contamination of Escherichia coli and Salmonella sp. inNham (Fermented Pork)

Abstract

Contamination of Escherichia coli and Salmonella sp. in samples of Nham were studied. All samples were collected during September 2010 to January 2011. The results showed the pH of samples were in the range of 2.3-6.9, samples of Nham were classified into 3 groups according to pH; 1) Nham which have pH lower than standard pH of Nham (2.3-4.3), it will be found 1 sample (5%) in September, 6 samples (30%) in October, 1 sample (5%) in December and 1 sample (5%) in January, 2) Nham which have pH similar to standard pH of Nham (4.4-4.6), it will be found 2 samples (10%) in September, 3 samples (15%) in October, 5 samples (25%) in November, 1 sample (5%) in December and 3 samples (15%) in January, 3) Nham which have pH higher than standard pH of Nham (4.7-6.9), it will be found 17 samples (85%) in September, 11 samples (55%) in October, 15 samples (75%) in November, 18 samples (90%) in December and 16 samples (80%) in January. Nham samples were tested for the total microorganisms count. The results showed the samples gave total microganisms count from 7.0-9.0 log CFU/g which is higher than the microbiological standard level of non-heated processing food. Colifrom and fecal colifrom bacteria were determined in Nham. The percentage of coliform bacteria on September, October, November, December 2010 and January 2011 were 15%, 5%, 15%, 10% and 15% respectively, the fecal coliform bacteria on September, October, November, December 2010 and January 2011 were 70%, 60%, 60%, 65% and 35% respectively. The results showed that amount of these bacteria exceeded the standard level. The biochemical test for fecal coliform bacteria identification, it can be classified as E.coli type II. In addition, Salmonella sp. were also tested, there were found 10% and 5% in September and December respectively, that exceeded the microbiological standard level.