Microbiological quality and HACCP of nono production in a Fulani settlement, Zaria Kaduna state, Nigeria

Abstract

This research studied the frequency of occurrence of Escherichia coli, Bacillus cereus, yeasts and moulds in some retail uncontrolled fermented milk samples (nono), and a hazard analysis was conducted to trace the sources of contamination during processing and suggest critical control measures. Fifty (50) nono samples purchased from Fulani milkmaids in Samaru market of Zaria town, Kaduna, Nigeria, were analyzed for presence of E. coli, B. cereus, Yeasts and Moulds. The traditional processing of nono by 3 producers of some of the market samples analyzed was studied by observing processing steps, processing environment, collecting raw and fermented milk samples, cow dung, hand swabs, swabs of milk contact surfaces, and exposing sterile plates to milking environment. Nono processing for all 3 producers involved spontaneous fermentation of fresh unpasteurized milk in calabashes at ambient temperature (25±40C) for 24 hours, fat separation from fermented milk, addition of water, whisking, packaging in calabashes and storing at ambient temperature before sale. Mean plate counts of market nono samples were at levels considered unsatisfactory for E. coli (≥ 102) in 76 %of samples, potentially hazardous for B. cereus (≥104) in 78% of samples and exceeded satisfactory limits for yeasts and moulds (<10) in all samples (100%). E. coli, B. cereus, yeasts and moulds were present in all 9 milk samples collected before and after fermentation during traditional processing. Yeasts and moulds were isolated from all samples (100%) during traditional processing except for wooden spoons (78%) and hand swabs (78%). Substandard practices like using unclean hands in manual milking and use of unpasteurized milk observed during traditional processing could explain presence of these microorganisms in market samples, as was also detected in raw and fermented milk during traditional processing. Findings of this study support that of previous researchers which established the impact of substandard processing techniques and hygiene on food quality.