ABSTRACT

Yoghurt is a nutritionally enriched dairy product consumed by all age groups particularly in summer as well as throughout all year; its microbial quality has always been crucially important to public health. The present study was conducted to assess the microbial quality of ice cream sold in Umuahia metropolis. A total of 5 samples were randomly purchased from fast-food joints, street vendors and hawkers within Umuahia metropolis respectively. It was recorded that the Total heterotrophic count for the yoghurt samples ranged from 5.4x105-8.8x105  (cfu/ml), with a mean count of  7.46±2.06(cfu/ml).  The Total Staphylococcal count of the samples ranged from 3.00x105 (cfu/ml) to 7.00x105 (cfu/ml). the highest count 7.00x105 (cfu/ml) was recorded in sample 4 (Y4) while the lowest count 3.00x105 (cfu/ml) was recorded in sample three (Y3).  The yoghurt samples had a mean Staphylococcal count of  5.2±2.2(cfu/ml). The Lactobacillus count ranged from 3.8x107-6.7x107 (cfu/ml) yoghurt samples with a mean of 5.06±1.26 (cfu/ml). The highest count 6.7x107 (cfu/ml) was recorded in sample 4 (Y4) while the least count 3.8x107 (cfu/ml) was recorded in sample two (Y2). The E.coli count (cfu/ml) was 1.00x105 (cfu/ml) in two yoghurt samples with a mean count of 0.4±0.6 (cfu/ml). E.coli was detected in only two samples. Salmonella spp. had a count 2.00x105 (cfu/ml) in only one sample, with a mean of 0.4±0.6(cfu/ml). Shigella spp. was only detected in one yoghurt sample and had a count 1.00x105(cfu/ml) with a mean count of  (cfu/ml).The Total coliform count ranged from 2.00x105-6.00x105 (cfu/ml) with a mean count of 3.00±1.00 (cfu/ml). The lowest count 2.00x105 [ (cfu/ml)] was recorded in sample five (Y5) while the highest count 6.00x105 [ (cfu/ml)] was recorded in sample 3 (Y3). The fungal count of the yoghurt samples ranged from 1.00x105-3.00x105  (cfu/ml). The least fungal count was recorded in sample Y2.  With a mean count of 2.2±1.2(cfu/ml). For the bacteria isolates, Lactobacillus spp, Staphlococcus spp and Bacillus spp.had the highest incidence (5 out of the 5 samples) and percentage occurrence (100%) while Shigella spp., Salmonella spp and Escherichia coli had the least incidence ( 1 out of the 5 samples) and percentage occurrence (20%). For the fungal isolates, Aspergillus spp.had the least incidence (1 out of the 5 samples) and percentage occurrence (20%), while Fusarium spp. had the highest incidence (5 out of the 5 samples) and percentage occurrence (100%). The proximate analysis shows the moisture content, protein, fibre, fat, ash and carbohydrate value of each yoghurt sample expressed as a percentage. Comparing the general counts, the study concluded that the microbial quality of yoghurt sold in Umuahia metropolis differ between samples. The presence of pathogenic organisms in the yoghurt samples should be viewed with concern by the consumers, producers, yoghurt manufacturing industries and the government since food poisoning by Staphylococcus aureus, Bacillus spp., Salmonella spp., and Shigellaspp. is possible through consumption of contaminated yoghurt.