A CONTROL OF MICROORGANIC CONTAMINATION IN THE MAJOR RAW MATERIALS OF STERILIZED MILK

Abstract

The raw milk, the milk-powder and the sugar are the main raw materials used in the sterilized milk process in Viet Nam. Owing to the small breeding scale and the bad hygienic condition of breeding facilities, the raw milk's hygienic quality is not stable. The milk-powder and the sugar are generally sustained a thermal treatment process, therefore their contaminaited bacteria and their spores tend to be thermostolerant. The contamination of pathogenous bacterium influences on the sensory properties and the nutritional quality of milk product. Consequently, the control of bacterial contamination is indispensable. This paper studied onbacterial contamination level of raw materials and some strains at several critical points of sterilized milk process. The result showed a high level of bacterial contamination in these raw materials. The infe.ctious microorganisms in milk-powder, semi-product and spoilted milk belonged to groups of Bacillus, Enterobacteriacea, Pseudomonas and Micrococcus