Bacterial contamination of Kale (Brassica oleracea acephala) along the supply chain in Nairobi and its environment

Objective: To assess the microbiological safety of kale (Brassica oleracea Acephala) produced from farms and those sold at the markets with special focus on coliforms, E.coli and Salmonella.Design: A cross sectional study.Setting: Peri-Urban farms (in Athi River, Ngong and Wangige), wet markets (in Kawangware, Kangemi and Githurai), supermarkets and high-end specialty store both within Nairobi city.Results: Mean coliform count on vegetables from farms were 2.6x105 ±5.0x105 cfu/g while those from the wet markets were 4.6x106 ±9.1x106 cfu/g, supermarkets, 2.6x106 ±2.7x106 and high-end specialty store 4.7x105 ±8.9x105. Coliform numbers obtained on kales from the wet markets and supermarkets were significantly higher (p<0.05) compared to those from farms, while kale samples purchased from high- end specialtystore had similar levels of coliform loads as those from the farms. E. coli prevalence in the wet markets, supermarkets and high-end specialty store were: 40, 20 and 20%, respectively. Salmonella was detected on 4.5 and 6.3% of samples collected from the farms in Wangige and wet market in Kawangware, respectively. Fecal coliforms in water used on farms (for irrigation) and in the markets (for washing the vegetables) exceeded levels recommended by World Health Organization (WHO) of 103 organisms per 100 milliliter while Salmonella was detected in 12.5% of washing water samples collected from Kangemi market.Conclusion: Poor cultivation practices and poor handling of vegetables along the supply chain could increase the risk of pathogen contamination thus puting the health of the public at risk, therefore good agricultural and handling practices should be observed

MICROBIOLOGICAL AND ACIDITY CHANGES DURING THE TRADITIONAL PRODUCTION OF KIRARIO: AN INDIGENOUS KENYAN FERMENTED PORRIDGE PRODUCED FROM GREEN MAIZE AND MILLET

ABSTRACT Using a previously pre-tested structured questionnaire, the traditional processing method for kirario (a traditional fermented porridge of the Merus in Kenya) was studied and documented. The biochemical and microbial profile changes during fermentation of kirario, both by the traditional method and in the laboratory were monitored for 48 hours. Samples of kirario from ten localities in the study region were analyzed. Samples of the final products from the traditional method were analyzed for total viable counts (TVC), lactic acid bacteria (LAB), lactococci, yeasts and moulds and coliforms, while the laboratory samples were taken at six (6)-hour intervals and analyzed for TVC, LAB, lactococci, and yeasts and moulds for 48 hours. The traditional product showed average TVC, LAB, lactococci, yeasts and moulds of 9.30, 9.63, 8.62, and 4.83 log 10 cfu/ml, respectively. Coliform counts were detected in only two of the samples at <1 log 10 cfu/ml. Analysis of the laboratory samples showed similar results. This showed that the production of kirario was reproducible and could be simulated in an industrial set-up for commercialization. In both the laboratory and traditional samples, the microbial counts were monitored at 6 hourly intervals for 48 hours. The initial pH of 6.4 dropped to 3.3 at the end of the fermentation, while the total titratable acidity increased to 3.15% from an initial value of 1.04%. The TVC, LAB, lactococci, yeasts and molds increased from initial counts of 8.20, 8.18, 7.20 and 5.86 log 10 cfu/ml to 9.64, 9.55, 5.38 and 0.70 log 10 cfu/ml, respectively at the end of the 48-hour fermentation. The coliform counts were low or not detected at all in majority of the samples. These results indicated high degree of hygiene in traditional processing of kirario as indicated by the very low or undetectable coliforms. This was also attributed to the effect of inhibition of growth of coliforms during fermentation. The results were also substantiated by unusually high levels of acid in both the traditional and laboratory products, corresponding to pH 3.0 to 3.5, which indicated high activity of the lactic acid bacteria in kirario

Microbiological And Acidity Changes During The Traditional Production Of Kirario: An Indigenous Kenyan Fermented Porridge Produced From Green Maize And Millet

Using a previously pre-tested structured questionnaire, the traditional processing method for kirario (a traditional fermented porridge of the Merus in Kenya) was studied and documented. The biochemical and microbial profile changes during fermentation of kirario, both by the traditional method and in the laboratorywere monitored for 48 hours. Samples of kirario from ten localities in the study region were analyzed. Samples of the final products from the traditional method were analyzed for total viable counts (TVC), lactic acid bacteria (LAB), lactococci, yeasts and moulds and coliforms, while the laboratory samples were taken at six (6)-hour intervals and analyzed for TVC, LAB, lactococci, and yeasts and moulds for 48 hours. The traditional product showed average TVC, LAB, lactococci, yeasts and moulds of 9.30, 9.63, 8.62, and 4.83 log10 cfu/ml, respectively. Coliform counts were detected in only two of the samples at <1 log10 cfu/ml. Analysis of the laboratory samples showed similar results. This showed that the production of kirario was reproducible and could be simulated in an industrial set-up for commercialization. In both the laboratory and traditional samples, the microbial counts were monitored at 6 hourly intervals for 48 hours. The initial pH of 6.4 dropped to 3.3 at the end of the fermentation, while the total titratable acidity increased to 3.15% from an initial value of 1.04%. The TVC, LAB, lactococci, yeasts and molds increased from initial counts of 8.20, 8.18, 7.20 and 5.86 log10 cfu/ml to 9.64, 9.55, 5.38 and 0.70 log10 cfu/ml, respectively at the end of the 48-hour fermentation. The coliform counts were low or not detected at all in majority of the samples. These results indicated high degree of hygiene in traditional processing of kirario as indicated by the very low or undetectable coliforms. This was also attributed to the effect of inhibition of growth of coliforms during fermentation. The results were also substantiated by unusually high levels of acid in both the traditional and laboratory products, corresponding to pH 3.0 to 3.5, which indicated high activity of the lactic acid bacteria in kirario