The incidence of Escherichia coli in dairy products from retail markets in the Stellenbosch region

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dc.contributor.advisorGouws, Pieteren_ZA
dc.contributor.authorIssel, Cherylen_ZA
dc.contributor.otherStellenbosch University. Faculty of Agrisciences. Dept. of Food Science.en_ZA
dc.date.accessioned2024-03-01T08:54:34Z
dc.date.accessioned2024-04-26T18:27:12Z
dc.date.available2024-03-01T08:54:34Z
dc.date.available2024-04-26T18:27:12Z
dc.date.issued2024-03
dc.descriptionThesis (MScFoodSc)--Stellenbosch University, 2024. en_ZA
dc.description.abstractENGLISH 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.en_ZA
dc.description.abstractAFRIKAANSE OPSOMMING: Verskeie voedselgebaseerde uitbrake wat aan Escherichia coli (E. coli) gekoppel kan word, is internasionaal aangemeld en gedokumenteer, en die bron van baie van die uitbrake is melk en melkprodukte. Melk vanuit die melkklier is gewoonlik steriel, maar dit kan mikroorganismes vanaf verskeie bronne bevat tydens produksie, verwerking en verspreiding. Die doel van hierdie navorsingsprojek was om die voorkoms van E. coli in sommige van die suiwelprodukte wat by kleinhandel markte in die Stellenbosch area verkoop word te ondersoek en dan enige risikofaktore te identifiseer. ‘n Totaal van 83 monsters is verkry en ontleed om die mikrobiese lading en die teenwoordigheid van kolivorme en voorkoms en teenwoordigheid van Escherichia coli in rou melk, gepasteuriseerde melk, vars room en gewone jogurt te bepaal. Standaardmetodes is gebruik om die mikrobiese lading te bepaal asook die teenwoordigheid van kolivorme en E. coli en die produkte is volgens voorafbepaalde kriteria gekies. Standaardplaattelling is gebruik om die mikrobiese lading te bepaal en die Internationale Suiwelfederasie metode 73A van 1985 is gebruik vir die kolivorme en E. coli analises. Kolivorm en E. coli plate is onder UV-lig ondersoek na inkubasie en alle fluoresserende kolonies is as positief vir E. coli beskou. Die voorkoms van E. coli was 50% in die rou melkmonsters (n=20) en afwesig in alle ander produkte (gepasteuriseerde melk, vars room en gewone jogurt). Gewone jogurt was die enigste produk wat geen kolivorme of E. coli bevat het in enige van die monsters wat ontleed is nie. Wanneer geevalueer volgens die standaarde voorgeskryf in die Wet op Voedsel, Skoonheidsmiddels en Ontsmettingsmiddels, 1972 (Wet No. 54 van 1972), gepubliseer onder Goewermentskennisgewing No. R1555 van 21 November 1997, het 85%, 25% en 47% van die monsters nie voldoen aan die kolivorm standaarde vir rou melk, gepasteuriseerde melk en vars room, onderskeidelik nie. Die voorkoms van E. coli in melk en melkprodukte kan toegeskryf word aan verskeie risikofaktore soos dieregesondheid, behuising en boerderypraktyke, skoonmaak van toerusting, higiëne van personeel, verkoelings en vervoertoestande, asook verwerkings en verspreidingstoestande. Die resultate dui daarop dat meer klem op higiëniese en verkoelingstoestande tydens alle stadiums van produksie, verwerking en verspreiding geplaas moet word.af_ZA
dc.description.versionMastersen_ZA
dc.format.extent63 pages : illustrationsen_ZA
dc.identifier.urihttps://scholar.sun.ac.za/handle/10019.1/130461
dc.language.isoen_ZAen_ZA
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : Stellenbosch Universityen_ZA
dc.rights.holderStellenbosch Universityen_ZA
dc.subject.lcshEscherichia coli -- Pathogenesisen_ZA
dc.subject.lcshDairy products -- South Africa -- Stellenbosch -- Marketingen_ZA
dc.subject.lcshMilk -- Quality -- South Africa -- Stellenboschen_ZA
dc.subject.lcshMilk -- Microbiologyen_ZA
dc.subject.lcshMilk -- Effect of temperature onen_ZA
dc.subject.lcshFoodborne diseasesen_ZA
dc.subject.lcshDairy products -- Storageen_ZA
dc.subject.nameUCTDen_ZA
dc.titleThe incidence of Escherichia coli in dairy products from retail markets in the Stellenbosch regionen_ZA
dc.typeThesisen_ZA
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