Browsing by Author "Issel, Cheryl"

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    The incidence of Escherichia coli in dairy products from retail markets in the Stellenbosch region
    (Stellenbosch : Stellenbosch University, 2024-03) Issel, Cheryl; Gouws, Pieter; Stellenbosch University. Faculty of Agrisciences. Dept. of Food Science.
    ENGLISH ABSTRACT: Several foodborne outbreaks linked to Escherichia coli (E. coli) have been reported and documented internationally and the source of many of the outbreaks were milk and milk products. Milk from the mammary gland is normally sterile, however, it can contain microorganisms from various sources during production, processing and distribution. The purpose of this research project was to investigate the incidence of E. coli in some of the dairy products sold at retail markets in the Stellenbosch region and to identify any risk factors. A total of 83 samples were sourced and analysed to determine the microbial load and the presence of coliforms and incidence and presence of Escherichia coli in raw milk, pasteurised milk, fresh cream and plain yoghurt. Standard methods were used to determine the microbial load and presence of coliforms and E. coli in the products. The products were chosen according to predetermined criteria. Standard Plate Count was used to determine the microbial load and International Dairy Federation method 73A of 1985 was used for the coliforms and E. coli enumeration. Coliform and E. coli plates were examined under UV light after incubation and all fluorescent colonies were regarded as positive for E. coli. The incidence of E. coli was 50% in the raw milk samples (n=20) and absent in all other products (pasteurised milk, fresh cream and plain yoghurt). However, plain yoghurt was the only product that contained no coliforms or E. coli in any of the samples analysed. When evaluated according to the standards prescribed in the Foodstuffs, Cosmetics and Disinfectant’s Act, 1972 (Act No. 54 of 1972), published under Government Notice No. R.1555 of 21 November 1997, 85%, 25% and 47% of samples were non-compliant to coliform standards for raw milk, pasteurised milk and fresh cream respectively. The incidence of E. coli in milk and milk products can be attributed to several risk factors like animal health, housing and husbandry practices, cleaning of equipment, hygiene of personnel, cooling conditions and transport, processing and distribution conditions. The results indicate more emphasis should be placed on hygienic and cooling conditions during all stages of production, processing and distribution.