Public health issues in the processing of cassava (Manihot esculenta) for the production of lafun and the application of hazard analysis control measures

Abstract

Eight hundred samples of water, fermenting broths and dried lafun obtained from processors from two villages in Ogbomoso, Nigeria were analysed within a period of five months for microbiological attributes through the enumeration and isolation of mould/yeast, mesophilic aerobic bacteria, coliform, staphylococci, Salmonella and lactobacilli. In addition, the public health implications of the incidence of bacteria and fungi were investigated through antibiotic sensitivity testing and determination of aflatoxigenic potential of fungal isolates. The raw materials and environments in which lafun processing was carried out was observed to identify sources of hazards associated with the production process, to construct a workable hazard analysis and critical control points plan for lafun production, which was implemented in the production of laboratory-prepared lafun. The cumulative microbial counts of the water and fermenting broths ranged from 1.35×104 to 1.04×105 cfu/ml, while that of lafun samples ranged from 2.21×104 to 9.91×104 cfu/g. There were occurrences of Staphylococcus aureus, Escherichia coli, Salmonella Typhimurium, Lactobacillus sp., Bacillus cereus, Klebsiella oxytoca, Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Absidia corymbifera and Rhizopus oryzae in the samples. Many of these isolates showed multi-drug resistance to 2-10 antibiotics, while about 39% of the fungi produced aflatoxins ranging from 1 to 1,600 μg/kg. The critical control points identified in the production were steeping, drying, packaging/storage, and the implementation of the corrective measures led to the production of laboratory-prepared lafun with improved microbiological safety. The results showed potential hazards that may be associated with the consumption of lafun with attendant public health consequences of aflatoxin food poisoning and illnesses that may be occasioned by multi-drug resistant bacteria. Education of processors on the hazards, critical control points and importance of hygienic environment is therefore necessary in the production of quality lafun to safeguard public health.