Hygienic quality of raw pork and chorizo (raw pork sausage) on retail sale in Mexico City

A survey of raw pork and a raw fermented pork sausage, chorizo, was undertaken in Mexico City to assess the hygienic quality of these two products on retail sale in a variety of outlets. Total bacterial counts and Enterobacteriaceae counts were determined and the samples were analyzed for the presence of Salmonella spp. Pork sold from refrigerated display cabinets in supermarkets and butchers' shops was of a poor microbial quality similar to that sold in street markets. In all types of outlets, a high proportion (76%) of samples contained Salmonella spp. Hygiene scores for vendors did not correlate with microbiological quality. For chorizo, the microbial quality was related to the type of producer. The product of major commercial companies had a lower mean Enterobacteriaceae count than that of small-scale producers, but although this difference was statistically significant, counts were high for a fermented meat product. Twenty percent of chorizo samples from major producers were positive for Salmonella spp. Small-scale or ''back-shop'' production resulted in 72% of samples being positive for Salmonella spp. Thus neither type of chorizo could be described as being a good quality and hygienic product. It is apparent that both animal husbandry and slaughter procedures for pigs require further study, as does the pork-processing industry, in order to define how the meat becomes so heavily contaminated. Improving the quality of the raw meat will benefit consumers in the Mexico City area and will be an essential prerequisite for improving the quality of chorizo.