English

Abstract

Sachets of various brands of yoghurt were randomly purchased from different retail outlets within Omoku schools and its pH and microbiological quality were determined using standard method. Total bacterial count (TBC) and Coliform count were done using standard plate count method after making serial dilutions of yoghurt samples. Nutrient agar (NA) was used for enumeration of TBC. NA plates were incubated at 37°C for 48 h. Coliform count was carried out using MacConkey agar (MCA) incubated at 37°C for 48 h. Total fungi were determined by using potato dextrose agar (PDA) and the plates were incubated at room temperature for 5-7 days. The pH of yoghurt samples ranged from 2.38±0.81 to 3.2±0.08, TBC ranged from 3.1 x 105  to 5.1x 105  cfu/mL. Total fungi count ranged from 3.2 x 103 to 4.9 x 103 cfu/mL. Total coliform count ranged from 0 to 1.0 cfu/mL. There was no significant difference in TBC and total coliform counts (p>0.05), but there was significant differences in total fungi counts (p<0.05). Results indicate that yoghurt sold in Omoku schools is of poor microbiological quality and thus their production and sale should be closely monitored in order to protect students and pupils and the general public from food-borne infection. Key words:  Contaminated, total bacteria count, total coliform, total fungi, bacteria, pathogens, yoghurt.