Microbiological quality evaluation of ready-to-eat mixed vegetable salad, food ingredients and some water samples from a restaurant in Accra: A case study

Abstract

One serious threat to public health in both developed and developing countries is the microbial contamination of food. This problem poses a great challenge and consequently has economic implications. Causes of microbial contamination are diverse and these may be natural, environmental, or technological. The microbiological quality of most ready-to-eat foods is of great significance to human health because they require minimal or no processing when consumed.The aim of this research was to investigate the microbiological quality of some ready-to-eat mixed vegetable salad foods, ingredients as well as the wash water samples of an urban restaurant located in Accra, Ghana. A total of thirty (30) samples categorized into mixed vegetable salads, foods and water obtained from an urban restaurant in the national capital of Ghana, Accra. They were analyzed at the microbiology laboratory and food microbiology laboratories of School of Allied Health Sciences(UHAS)and Council for Scientific and Industrial Research-Food Research Institute (CSIR-FRI), Ghana,respectively. Standard microbiological methods that are per International Organization for Standardization(ISO) Methods and Nordic Committee on Food Analysis Methods (NMKL) were used in determining the presence and levels of bacteria and fungi.Data obtained were transformed from standard to logarithmic forms and reported as mean+standard deviations. The aerobic plate count samples ranged from 0-4.73 log 10CFU/g. E-coli counts also ranged between 0-2.53 log 10CFU, while Bacillus cereus counts were very low at0-<10log 10CFU/g. Clostridium perfringens and Staphylococcus aureus counts were also very low ranging from0-1.0log10CFU/g.Enterobacteriaceae counts also ranged from 0-1.90 log10CFU/g. Molds and yeasts counts were generally low and ranged from 0-2.48 log 10CFU/g and 0-1.0 log10CFU/g,respectively. None of the samples tested contained Listeria monocytogenes and Salmonella spp. Fungal microbial loads were minimal given the quantities, and were deleterious to the health of consumers. The study revealed that the bacterial loads on mixed vegetable salads, ingredients and water samples used and served by an urban restaurant in Accra were within safe limits according to American Public Health Association (APHA) and International Commission for Microbiological Specifications for Foods (ICMSF) guidelines and,therefore,good for human consumption.