Evaluation of the Microbial Contamination of Some Snacks: A Case Study of Lagos Mainland, Lagos State, Nigeria

Abstract

This study was undertaken to evaluate the microbial contamination of some locally prepared snacks sold by street vendors in Lagos mainland, Lagos State, Nigeria. A total of (20) twenty snack samples- Meat-pie, Sausage roll, Egg roll, Puff puff and Doughnut were aseptically purchased in a sterilized polythene bags from four different locations in Lagos Mainland Local Government Area. The snacks were analyzed by standard microbiological methods using Bergey’s manual to determine the colony-forming units per gram, to isolate and determine the number of microbiological population contaminants. Unilag showed the bacteria count on snacks as follows: Meat-pie 1.50 × 106 cfu/ g), Sausage 2.20× 106 cfu/ g, Doughnut 3.20× 105 cfu/ g, Puffpuff 1.58x 106 cfµ/ g and Egg roll 9.80x105 cfµ/ g. At Yaba - Meat pie had bacteria count of 1.82x102cfµ / g, Sausage 7.00x101cfµ / g, Doughnut 1.09x 102 cfµ /g, Puff puff 3.64x104 cfµ/ g and Egg roll 5.00x101 cfµ/g.  Snacks from Oyingbo had no growth on Meat pie, Doughnut and Puff puff but had bacteria cou nts on Sausage (1.00x102) and on Egg roll (1.95× 105 cfµ/ g).At Abule-Oja- Meat pie had bacteria count of 9.75x104 cfµ/ g, Puff puff 1.65x105 cfµ/ g and Egg roll 1.95x105 cfu/ g.The location with lowest bacteria count was Oyingbo which had no growth on a Meat pie, Doughnut and Puff puff, but had on Sausage 1.00x102 cfµ/ g and Egg roll 9.60x102 cfµ/ g. There were no coliforms in all the locations. Bacteria percentage range was 10.52%   to 36.84%while Fungi percentage range was 0.71% - 37.59%. Four bacteria and seven fungi were identified: Bacillus cereus, Bacillus substillis, Staphylococcus aureus, Lactobacillus delbruckii with Aspergillus niger, Penicillium notatum, Trichoderma spp., Aspergillus fumigatus, Saccharomyces cerevisiae, Fusarium spp. and Aspergillus flavus. Bacillus cereus had the highest prevalence of 36.84%, Bacillus substillis 31.58%, Staphylococcus aureus 21.05% and Lactobacillus delbruckii 10.52%. Bacillus species were present at all sampled sites. It is concluded that the quality of these snacks   can be improved by following quality control protocol and good manufacturing practices (GMP) in food.