Microbial Quality Assessment of Ice Cream Sold in Umuahia, South-Eastern Nigeria: A Comparative Study

Abstract

Microbial analysis was conducted on seventeen ice cream samples; industrially produced (X₁-X₇), locally produced (Y₁-Y₆) and fast food ice cream (Z₁-Z₄) purchased within Umuahia respectively. The total aerobic plate count (TAPC) and the total fungal count (TFC) ranged from 4.05×10⁴ (Z₄) to 1.83×10⁵ (Y₃) cfu/g (TAPC); and 1.00×10³ (Y₄) to 3.00×10³ (X₂, X₇, Y₁, Y₂, Y₃, Y₅, Y₆) cfu/g (TFC). The total coliform count (TCC), the total Staphylococcal (TSC) and Salmonella counts (SAC) ranged from 8.00×10³ (X₃), to 3.80×10⁴ (Y₆) cfu/g (TCC); 3.00×10³ cfu/g (X₂), to 1.50×10⁴ (Y₂) cfu/g (TSC); and 2.00×10³ (X₇), to 1.30×10⁴ (Y₁) cfu/g (SAC); with a zero count for the fast food samples. Escherichia coli (EC) and Shigella counts (SHC) ranged from 4.00×10³ (Y₂), to 1.20×10⁴ (Y₆) cfu/g (EC) and 4.00×10³ (Y₃), to 6.00×10³ (Y₂) cfu/g (SHC); with a zero count for both the industrially produced and fast food samples. The Lactobacillus count ranged from 3.65×10⁴ (X₅) to 9.35×10⁴ (X₄) cfu/g. The distribution of the isolates include: Staphylococcus aureus 7 (41.18%), Lactobacillus spp. 17 (100%), Bacillus spp. 13 (76.47%), Shigella spp. 2 (11.76%), Salmonella spp. 3 (17.65%), Escherichia coli 4 (23.53%), Streptococcus spp. 9 (52.94%), Aspergillus spp. 1(5.88%) and Fusarium spp. 16 (94.12%). Statistical analysis showed a significant difference between the ice cream sample categories (P<0.05; P<0.01). Comparing the general counts, the study concluded that the microbial quality of ice cream sold in fast food joints in Umuahia was better than the other two categories. The presence of food-borne pathogens beyond the acceptable limit is of public health importance.

Keywords: microbial quality, ice cream, Umuahia, comparative study.