Microbiological Criteria in the Manufacture of Pasteurized Milk

Abstract

The process hygiene criterion is a microbiological criterion that applies to the process offood production and processing and indicates the proper functioning of the production process byrepresenting the value of the contamination above which corrective measures are taken to maintainthe process hygiene. Pasteurized milk is a product obtained by heat treatment of raw milk at atemperature of 63° C for 30 minutes or 72° C for 15 seconds. Pasteurization has two purposes, thefirst one is to elimination of all pathogenic microorganisms, and the second is to reduce the numberof saprophytic microorganisms, which prolongs the shelf life without changing the nutritional andbiological value of the milk.The aim of the study is to examine the safety of pasteurized milk and the conditions of hygiene inthe production process based on the results of the examination of pasteurized milk on the criteria ofhygiene in the production process, as well as to develop a proposal for the recommendedmicroorganisms to be tested in the process of the production of pasteurized milk.Samples of pasteurized milk come from a pasteurizing plant that purchases milk from the territoryof Republika Srpska, and were sampled in the six-month period (January-June), within self-controland official control. For microbiological testing of raw milk, standard BAS ISO methods were used.The results of pasteurized milk testing in relation to the hygiene criteria in the production processare satisfactory in relation to the Rulebook on Microbiological Criteria for Food. The results of selfcontrolon the recommended microbiological criteria in the process of obtaining pasteurized milk,which are given in the Guideline on the Application of Microbiological Criteria for Food, aresatisfactory in relation to the finding of Listeria monocytogenes, Salmonella spp. and coagulasepositive staphylococci, and unsatisfactory for a number of microorganisms.The results of official controls in the production process of pasteurized milk are unsatisfactory dueto the increased number of microorganisms in 12.50% of the samples. 22.20% of pasteurized milksamples had the number of microorganisms larger than 105CFU/ml within self-control and officialcontrols. Examination of pasteurized milk in the self-control of the production process should beperformed on enterobacteria and the total count of microorganisms, and in the interpretation of theresults the recommended limit values from the Guideline on the application of microbiologicalcriteria for food should be used.

Assessing hygiene indicators in two dairies in Algeria in producing pasteurized milk

“…Foodborne diseases caused by pathogenic microorganisms are more frequent than those due to harmful chemicals and plants [6]. The application of heat treatment, such as pasteurization, is sufficient to reduce 99.99% of pathogenic and non-pathogenic microorganisms in raw milk [7]. This treatment eliminates or inactivates all vegetative forms of bacteria, psychrotrophic microorganisms, yeasts and molds, and certain unwanted enzymes while preserving the food value of milk [4,8].…”

“…In the US dairy industry, coliforms have been used since 1914 as indicator organisms [17]. They were recommended by the US Public Health Service in the first edition of the Pasteurized Milk Ordinance published in 1924 [6,7]. They continue to be used for this purpose.…”