Analyse physico-chimique et microbiologique de lait cru de vache élevée dans la région d’Ain Témouchent.

Abstract

The present work focused on physicochemical and microbiological analysis of eight samples of raw cows' milk from two SARL and Sidi Saïd dairies located in the region of Ain Témouchent. The physicochemical analyzes showed that the temperatures and pH values measured in the eight samples of raw milk were between 4 and 6 °C and 6.6 and 6.8 respectively, and this was within the required standards. On the other hand, the measured dornic acidities were 18.62 ± 1.69 °D for the SARL dairy and 20.5 ± 0.25 °D for the dairy Sidi Saïd, these values are higher than the norms. The results of alcohol and C.O.B tests were negative for the four samples from the SARL dairy. On the other hand, Dairy Sidi Saïd, showed a positive alcohol test for three samples, and a C.O.B test, positive for two samples. The microbiological analyzes showed that the dairy milk of the SARL dairy contains 1.68 × 103 CFU / ml of the FAMT, 0.71 × 103 CFU / ml of total coliforms and 0.95 × 103 CFU / ml of faecal coliforms. On the other hand, milk from the Sidi Saïd dairy contains 6.124 × 103 CFU / ml of FAMT, 4.97 × 103 CFU / ml of total coliforms and 18.95 × 103 CFU / ml of faecal coliforms. The values of these microbial comply the standards required by the Algerian official journal, except for the value of faecal coliforms from the dairy Sidi Saïd, which has been well above the norm. Staphylococcus aureus, Gram positive and catalase positive, were present in the raw milk of the dairy Sidi Said with an average load equal to 5.17 × 103 CFU /ml, but totally absent in that of the dairy SARL. For Salmonella, there was a complete absence of this germ in the raw milk analyzed for both dairies. At the end of this study we can conclude that the milk of the dairy SARL is of good microbiological quality, while that of the dairy of Sidi Saïd requires more extensive tests to better understand the origin of the noted contaminations.