Quality Control of Milk in the Dairy Industry

The quality has always been a requirement of safety in the modern economy in Algeria; it is also an ongoing concern, if not a priority or a necessity as well and foremost for the consumer and for the producer and the processor, activating within the chain of production and marketing of milk and dairy products. Series of analyzes were performed on milk powder as raw material and the reconstituted milk pasteurized and packaged in one-litter bag as a finished product to determine quality health and hygiene. In addition, further analyses were also performed on the water incorporated in the reconstitution of milk on equipment surfaces and finally the atmosphere to determine and assess the degree of potability and hygiene at the central dairy. The test results showed that of the 31 samples of milk powder made, we have found no microbiological, radioactive and antibiotics contamination. Regarding physical chemistry, 04 samples showed a slight acidity between 16 and 17° D. While the humidity and solubility index of milk powder were consistent with the regulations. Microbiological results of reconstituted milk and pasteurized showed that out of 35 samples, no contamination by germs alteration or contamination was found, but the physico-chemical analyzes showed the presence of a wetting caused by low content of total solids and density on selected samples. The fat content in all samples was consistent with the regulations and it was between 1.5 and 1.7%. No changes did affect the organoleptic quality of the milk powder and reconstituted milk, on the point of view taste, odour and colour. The microbiological analyzes of the 16 samples of water recovery showed that 07 of them were of poor quality, given the presence of aerobic bacteria and aerobic coliforms in their level, which are probably due to poor maintenance of the piping which carries water to the interior of the central dairy. The control of local atmosphere and surface equipments revealed the presence of many of total germs within the powder, recovery and packaging rooms, among others with little yeasts and moulds, which explains that air can be suspected to play the role of particles spread milk powder into the atmosphere and deposited on the floor of the rooms or areas. The results also showed the absence of Salmonella, yeasts and moulds and the presence of some tolerable total germs on surfaces of equipment used in the process of manufacture of reconstituted milk, after the operation of cleaning and disinfection.