Analysis of Groundnuts Sold by Street Vendors in Gaborone for Hygiene and Aflatoxin Content

Background: Street-vended foods are integral to urban food systems in developing countries, yet pose significant public health risks due to inadequate hygiene practices and contamination hazards. This study assessed the microbiological quality and aflatoxin contamination of ready-to-eat groundnuts sold by street vendors in Gaborone, Botswana.
Methods: A cross-sectional study was conducted among 37 street vendors operating in three commercial hubs of Gaborone between March and May 2019. Vendors were surveyed using structured questionnaires, and composite groundnut samples (one per vendor) were collected for laboratory analysis. Hygiene status was evaluated through enumeration of Escherichia coli using serial dilution and plating on selective agar. Aflatoxin concentrations (B1, B2, G1, G2) were quantified using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) following immunoaffinity column clean-up.
Results: All 37 composite samples (100%) exhibited unacceptable microbiological contamination, with E. coli counts ranging from 2.0 × 10⁵ to 1.86 × 10⁶ CFU/g (mean 8.42 × 10⁵ ± 4.95 × 10⁵ CFU/g), substantially exceeding the guideline threshold of <1 × 10² CFU/g for ready-to-eat foods. Aflatoxin analysis revealed severe contamination, with 94.6% (35/37) of samples exceeding Botswana's regulatory limit of 10 µg/kg for total aflatoxins. Total aflatoxin concentrations ranged from below the detection limit to 1966.72 µg/kg, with aflatoxin B1 as the predominant congener. Key contributing factors identified included lack of vendor licensing (97.3%), sourcing from Zambia (81.1%), inadequate storage in non-breathable containers (59.5%), and absence of personal protective equipment (70.3%).
Conclusion: Street-vended groundnuts in Gaborone present a dual public health threat from biological and chemical contamination. The findings underscore systemic failures in food safety governance within the informal sector and suggest the need for integrated interventions spanning regulation, vendor education, infrastructure improvement, and supply chain management.

Aflatoxin, Escherichia coli, Food Safety, Street Food, Groundnuts, Gaborone, Public Health

1. Ababio, P.F. and Lovatt, P. (2015) 'A review on food safety and food hygiene studies in Ghana', Food Control, 47, pp. 92-97. doi:10.1016/j.foodcont.2014.06.041. [Google Scholar] [Crossref]

2. Bartlett, J.E., Kotrlik, J.W. and Higgins, C.C. (2001) 'Organizational research: Determining appropriate sample size in survey research', Information Technology, Learning, and Performance Journal, 19(1), pp. 43-50. [Google Scholar] [Crossref]

3. Bhatnagar-Mathur, P., Sunkara, S., Bhatnagar-Panwar, M., Waliyar, F. and Sharma, K.K. (2015) 'Biotechnological advances for combating Aspergillus flavus and aflatoxin contamination in crops', Plant Science, 234, pp. 119-132. doi:10.1016/j.plantsci.2015.02.009. [Google Scholar] [Crossref]

4. Bhowmik, S.K. (2005) 'Street vendors in Asia: A review', Economic and Political Weekly, 40(22/23), pp. 2256-2264. [Google Scholar] [Crossref]

5. Cochran, W.G. (1977) Sampling Techniques. 3rd edn. New York: John Wiley and Sons. [Google Scholar] [Crossref]

6. Cortese, R.D.M., Veiros, M.B., Feldman, C. and Cavalli, S.B. (2016) 'Food safety and hygiene practices of vendors during the chain of street food production in Florianopolis, Brazil: A cross-sectional study', Food Control, 62, pp. 178-186. doi:10.1016/j.foodcont.2015.10.027. [Google Scholar] [Crossref]

7. Daniel, W.W. (1999) Biostatistics: A Foundation for Analysis in the Health Sciences. 7th edn. New York: John Wiley and Sons. [Google Scholar] [Crossref]

8. Dawson, R.J. and Canet, C. (1991) 'International activities in street foods', Food Control, 2(3), pp. 135-139. doi:10.1016/0956-7135(91)90015-Q. [Google Scholar] [Crossref]

9. Food and Agriculture Organization of the United Nations (FAO) (2007) Promises and challenges of the informal food sector in developing countries. Rome: FAO. [Google Scholar] [Crossref]

10. Food and Agriculture Organization of the United Nations and World Health Organization (FAO/WHO) (2016) Addressing food safety in the informal sector. Rome and Geneva: FAO/WHO. [Google Scholar] [Crossref]

11. Gong, Y., Hounsa, A., Egal, S., Turner, P.C., Sutcliffe, A.E., Hall, A.J., Cardwell, K. and Wild, C.P. (2004) 'Postweaning exposure to aflatoxin results in impaired child growth: A longitudinal study in Benin, West Africa', Environmental Health Perspectives, 112(13), pp. 1334-1338. doi:10.1289/ehp.6954. [Google Scholar] [Crossref]

12. Government of Botswana (2011) Food Control: Subsidiary Legislation (Maximum Levels of Aflatoxins in Food) Regulation Chapter 65:05. Gaborone: Government Printer. [Google Scholar] [Crossref]

13. Grace, D. (2015) 'Food safety in low-and-middle income countries', International Journal of Environmental Research and Public Health, 12(9), pp. 10490-10507. doi:10.3390/ijerph120910490. [Google Scholar] [Crossref]

14. Graffham, A., Karehu, E. and MacGregor, J. (2005) 'Impact of supermarkets on food safety and nutrition in Kenya', Agricultural Economics, 33(s1), pp. 11-23. doi:10.1111/j.1574-0862.2005.00484.x. [Google Scholar] [Crossref]

15. Guchi, E. (2015) 'Aflatoxin contamination in groundnut (Arachis hypogaea L.) caused by Aspergillus species in Ethiopia', Journal of Applied and Environmental Microbiology, 3(1), pp. 11-19. doi:10.12691/jaem-3-1-3. [Google Scholar] [Crossref]

16. Havelaar, A.H., Kirk, M.D., Torgerson, P.R., Gibb, H.J., Hald, T., Lake, R.J., Praet, N., Bellinger, D.C., de Silva, N.R., Gargouri, N., Speybroeck, N., Cawthorne, A., Mathers, C., Stein, C., Angulo, F.J. and Devleesschauwer, B. (2015) 'World Health Organization global estimates and regional comparisons of the burden of foodborne disease in 2010', PLoS Medicine, 12(12), e1001923. doi:10.1371/journal.pmed.1001923. [Google Scholar] [Crossref]

17. Hell, K. and Mutegi, C. (2011) 'Aflatoxin control and prevention strategies in key crops of Sub-Saharan Africa', African Journal of Microbiology Research, 5(5), pp. 459-466. doi:10.5897/AJMR10.038. [Google Scholar] [Crossref]

18. International Agency for Research on Cancer (IARC) (2012) Chemical agents and related occupations: A review of human carcinogens. Lyon: World Health Organization. [Google Scholar] [Crossref]

19. Jongh, L. (2015) 'Street vending in urban Malawi: Strategies and practices of vendors and local authorities', available at: http://www.rczi.org/wpcontent/uploads/2014/12/D2-Jongh.pdf (Accessed: 15 January 2020). [Google Scholar] [Crossref]

20. Kensler, T.W., Roebuck, B.D., Wogan, G.N. and Groopman, J.D. (2010) 'Aflatoxin: A 50-year odyssey of mechanistic and translational toxicology', Toxicological Sciences, 120(Suppl. 1), pp. S28-S48. doi:10.1093/toxsci/kfq283. [Google Scholar] [Crossref]

21. Khairuzzaman, M., Chowdhury, F.M., Zaman, S., Al Mamun, A. and Bari, M. (2014) 'Food safety challenges towards safe, healthy, and nutritious street foods in Bangladesh', International Journal of Food Science, 2014, Article 483519. doi:10.1155/2014/483519. [Google Scholar] [Crossref]

22. Kimanya, M.E., De Meulenaer, B., Roberfroid, D., Lachat, C. and Kolsteren, P. (2010) 'Fumonisin exposure through maize in complementary foods is inversely associated with linear growth of infants in Tanzania', Molecular Nutrition and Food Research, 54(11), pp. 1659-1667. doi:10.1002/mnfr.200900483. [Google Scholar] [Crossref]

23. Liu, Y. and Wu, F. (2010) 'Global burden of aflatoxin-induced hepatocellular carcinoma: A risk assessment', Environmental Health Perspectives, 118(6), pp. 818-824. doi:10.1289/ehp.0901388. [Google Scholar] [Crossref]

24. Lwanga, S.K. and Lemeshow, S. (1991) Sample Size Determination in Health Studies: A Practical Manual. Geneva: World Health Organization. [Google Scholar] [Crossref]

25. Muinde, O.K. and Kuria, E. (2005) 'Hygienic and sanitary practices of vendors of street foods in Nairobi, Kenya', African Journal of Food, Agriculture, Nutrition and Development, 5(1). Available at: https://www.ajol.info/index.php/ajfand/article/view/13566 (Accessed: 10 January 2020). [Google Scholar] [Crossref]

26. Mupunga, I. (2013) A comparative study of natural contamination with aflatoxins and fumonisins in selected food commodities from Botswana and Zimbabwe. Master's thesis. University of Zimbabwe. [Google Scholar] [Crossref]

27. Naing, L., Winn, T. and Rusli, B.N. (2006) 'Practical issues in calculating the sample size for prevalence studies', Archives of Orofacial Sciences, 1, pp. 9-14. [Google Scholar] [Crossref]

28. National Climate Change Response Strategy (NCCRS) (2010) National Climate Change Response Strategy (First Draft). Lusaka: Ministry of Tourism, Environment and Natural Resources, Government of Zambia. [Google Scholar] [Crossref]

29. Omemu, A.M. and Aderoju, S.T. (2008) 'Food safety knowledge and practices of street food vendors in the city of Abeokuta, Nigeria', Food Control, 19(4), pp. 396-401. doi:10.1016/j.foodcont.2007.04.021. [Google Scholar] [Crossref]

30. Rane, S. (2011) 'Street vending and food safety in India', Journal of Environmental and Public Health, 2011, Article 763480. doi:10.1155/2011/763480. [Google Scholar] [Crossref]

31. Steyn, N.P. and Labadarios, D. (2011) 'Street foods and fast foods: The nutrition transition in South Africa', South African Journal of Clinical Nutrition, 24(1), pp. 22-28. doi:10.1080/16070658.2011.11734306. [Google Scholar] [Crossref]

32. Tsang, D. (2002) Microbiological guidelines for ready to eat food. Hong Kong: Food and Environmental Hygiene Department. [Google Scholar] [Crossref]

33. Unnevehr, L. and Grace, D. (2013) Aflatoxins: Finding solutions for improved food safety. Washington, DC: International Food Policy Research Institute. [Google Scholar] [Crossref]

34. Williams, J.H., Phillips, T.D., Jolly, P.E., Stiles, J.K., Jolly, C.M. and Aggarwal, D. (2004) 'Human aflatoxicosis in developing countries: A review of toxicology, exposure, potential health consequences, and interventions', American Journal of Clinical Nutrition, 80(5), pp. 1106-1122. doi:10.1093/ajcn/80.5.1106. [Google Scholar] [Crossref]

35. World Health Organization (WHO) (2015) WHO estimates of the global burden of foodborne diseases: Foodborne disease burden epidemiology reference group 2007-2015. Geneva: WHO Press. [Google Scholar] [Crossref]

36. World Health Organization (WHO) (2022) WHO Global Strategy for Food Safety 2022-2030. Geneva: WHO Press. [Google Scholar] [Crossref]

37. Zain, M.E. (2011) 'Impact of mycotoxins on humans and animals', Journal of Saudi Chemical Society, 15(2), pp. 129-144. doi:10.1016/j.jscs.2010.06.006. [Google Scholar] [Crossref]

• Methane Emissions from Municipal Solid Waste - Case Study in Cai Rang District, Can Tho City, Vietnam
• Youth Activism, Intentional Integration of Policies to Raise Awareness on Climate Change Action among the Youth
• Breathing Spaces: Environmental & User Experience in Dhanmondi and Zigatola Multistoried Apartments, Dhaka, Bangladesh
• Effects of Solid Waste Disposal on Soil Quality in Makurdi Metropolis, Benue State, Nigeria
• Environmental Impact of Artisanal and Small-Scale Gold Mining in Borgu Local Government Area