ISOLATION, CHARACTERIZATION AND IDENTIFICATION OF MICROORGANISMS RESPONSIBLE FOR SPOILAGE OF DAIRY PRODUCTS (MILK AND YOGHURT)

ABSTRACT Yoghurt and Milk is food that inherently favours microbial growth and due to its characteristics several precautions must be taken to prevent contamination in its production, processing and consumption, which are routinely subject to changes. This study was carried out to isolate and identify microorganisms responsible for spoilage of some dairy products (milk and yoghurt). Samples were collected from Owode market Offa Kwara State between July to August 2023. The samples were serially diluted and inoculated using the streaking technique. The findings revealed that the peak milk recorded the highest means bacterial count of 8.333 x 106cfu/ml, while hollandia milk recorded the least means bacterial count of 4.667 x106 CFU/ml and there was no significant difference between this and other values obtained at p≤0.05. Amongst the organisms isolated, Bacillus sp., Escherichia coli and Staphylococcus sp. findings from proximate analysis showed that holladia yoghurt recorded highest ash and fibre contents with values of 0.32 and 0.21 respectively. High heterotrophic count obtained in this work is an indication of poor sanitary condition and this call for scrupulous hygienic measures during the handling of milk and yoghurt.