Qualite microbiologique du lait cru destine a la fabrication d’un type de camembert dans une unite de l’est Algerien.

Abstract

Samples of raw milk (30), for the manufacture of Camembert type cheese at a dairy in eastern Algeria, were analyzed during the period of high lactation (February-April 2011). The results of physico-chemical characteristics (acidity and density) are close to the standards, only the fat content is low, with an average of 30.9 g / l, it depends mainly on the dietary factor. Microbiological analysis is focused on 9 microbial groups: among the groups hygiene indicators (total bacteria, psychrotrophic, thermoduric, coliform and Escherichia coli) and some groups potentially pathogens (Staphylococcus aureus, Salmonella). Contamination levels were interpreted on the basis of microbiological criteria set by the ministerial decree of 24 January 1998. Enumeration of total aerobic mesophilic flora, psychrotrophic and thermoduric of serves to underscore the severe contamination of the samples analyzed with respective averages of 28,8.106 CFU / ml, 12,3.105 CFU / ml and 44,2.104 CFU/ml. Milk samples are contaminated with total coliforms, fecal coliforms and fecal streptococci with average respective 50,3.105 CFU / ml, 36,7.104 CFU / ml and 55,4.105 CFU/ml. The germ E. coli is present in 64% of milk analyzed. The presence of pathogens is mainly attributed to staphylococci with an average of 37,5.102 CFU /ml, 80% of isolates were coagulase positive. The study of their susceptibility patterns to antibiotics showed a frequency of resistance (100%) vis-à-vis penicillin G, very little resistance vis-à-vis the oxaciline (8%) of tetracycline (17%) and trimethoprim + sulfamethoxazole association (17%). No resistance was observed for cefoxitin, erythromycin, enrofloxacin, and vancomycin. Moreover, we note the absence of Salmonella in all samples. In view of the Algerian standards (JORA, 1998), the hygienic quality of all milk samples analyzed, is bad. Milks are heavily polluted, revealing questionable hygiene practices, that even the best cooling conditions of milk, can not, under any circumstances, hide. These results can only strengthen the conviction of the urgent need for technical support in this area, coupled with the revision of payment of milk: the inclusion criteria daily as basic as the milk fat and protein and contamination by microorganisms. There will surely sustainability in Algeria of a dairy industry that is capable of distinguishing the various versions of a product as variable and perishable as milk.