Physicochemical Properties, Proximate Composition and Total Viable Counts of Staphylococcus aureus in ‘Nono’ And Yoghurt Samples in Kaduna, Nigeria

Abstract

The study aims at determining the physicochemical, proximate composition and the total viable count of Staphylococcus aureus in ‘Nono’ and yoghurt samples in Kaduna, Nigeria.Three hundred and eighty-four (384) fermented milk samples (Nono and yoghurt) were obtained from different selling points and were evaluated for the occurrence of S. aureus. The physicochemical and proximate analyses (pH, total titratable acidity, moisture content, ash content, protein content, and fat content) were determined. The results of the analyses showed that Nono had pH range of 3.56-3.61, total titratable acidity: 0.71-1.72, moisture content: 82.23-83.87%, ash content: 0.30-0.31%, crude protein content: 1.50-1.61%, crude fat content: 0.35-0.38 %. For yoghurt, the pH ranged from 3.76 -3.82, total titratable acidity: 1.10 -1.15, moisture content: 77.76-80.06%, ash content: 0.68- 0.70%, crude protein content: 3.40-3.45% and crude fat content: 1.76-1.79% from all the study areas. One hundred and four of the total samples were contaminated with S. aureus. Out of the 104 isolates of S. aureus that were isolated and identified, 88 were coagulase positive S.aureus. The Microgen Staph ID kit (Oxoid) was used to further confirm the characteristics of the 60 isolates of the coagulase positive S. aureus. The kit confirmed 43 isolates as S. aureus, the results indicated the presence of S. aureus in the milk samples which is of public health importance, as this can contribute to food-borne intoxication which can lead to food poisoning. There is a need for proper pasteurisation of raw milk to help eradicate S. aureus infection before human consumption.