A comparison of selected public health criteria in milk from milk-shops and from a national distributor.
Selected public health criteria of pasteurised milk available to the consumer from milk-shops in a pre-defined area of Pretoria compared with a national distributor's milk was evaluated. Of the 135 milk samples purchased from milk-shops, 87% were not fit for human consumption on the basis of the minimum standards prescribed in the Foodstuffs, Cosmetics and Disinfectants Act, 1972 (Act 54 of1972). The national distributor's milk (n = 79) did not contain any pathogens, toxins nor inhibitory substances and passed all the criteria laid down in the Act. Even though milk-shop milk was sold as having been pasteurised, 38.5% of samples were alkaline phosphatase positive, indicating probable inadequate pasteurisation. Milk-shop milk quality varied between milk-shops and between sampling days and differed significantly (P < 0.05) from the national distributor's milk. Total aerobic plate and coliform counts were generally high for all milk-shop milk samples. Somatic cell counts of milk-shop milk differed significantly (P < 0.05) from the national distributor's milk. Escherichia coli was detected in 1 ml of 17% of milk-shop milk, 95% of which originated from milk which was alkaline phosphatase positive. Salmonella spp. could not be detected in 1 ml in any of the E. coli-positive milk tested. Staphylococcus aureus was isolated from 40% of milk-shop milk samples, and S. aureus enterotoxins from 7.8% of 51 cultures. Inhibitory substances were detected in 54.1% of milk-shop milk. The presence of inhibitory substances and the isolation of E. coli and S. aureus (some of which were able to produce enterotoxins) indicated potentially unsafe milk and poses a serious public health risk to consumers.
O'Ferrall-Berndt
M More
MM
Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa. romamof@icon.co.za
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis; D002417:Cattle; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004926:Escherichia coli / Q000254:growth & development / Q000378:metabolism; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D006801:Humans; D008414:Mastitis, Bovine / Q000453:epidemiology; D008892:Milk / Q000166:cytology / Q000382:microbiology / Q000592:standards*; D011634:Public Health; D013211:Staphylococcus aureus / Q000254:growth & development / Q000378:metabolism
D001427:Bacterial Toxins; D000469:Alkaline Phosphatase