Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 11: 564 - 569. Published October 31, 2008.
Management of spoilage and pathogenic organisms during fermentation of nono - an indigenous fermented milk product in Nigeria
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^Corresponding author e–mail:zzz
ABSTRACT
Objectives: The ability of lactic acid bacteria to suppress the growth of spoilage and pathogenic organisms during nono fermentation was investigated.
Methodology and results: Pasteurized milk samples were inoculated with selected spoilage and pathogenic organisms. Lactic acid bacteria (1%) were then inoculated singly or in-combination into the milk samples for evaluation as protective cultures. The treated milk was fermented at 30°C for 24h. Changes in pH, titratable acidity (TA) and viable counts of the inoculated indicator organisms were determined at specific intervals during nono fermentation. The pH of fermenting nono ranges between pH 4.08 and 5.9. A significant increase (P≤ 0.05) in TA values was observed ranging between 0.4 and 1%. There was a significant increase (P≤ 0.05) in the viable counts of Pseudomonas aeruginosa, Proteus vulgaris, Enterobacter aerogenes and Staphylococuss aureus. However, a significant decrease (P≤ 0.05) in the viable counts of E. coli, Bacillus cereus, Salmonella typhi and Klebsiella sp. were recorded after fermentation for 24 hours.
Conclusion and application of findings: This study shows that spoilage and pathogenic organisms could survive in milk during nono production. A mixture of L. plantarum and L. bulgaricus could be useful as protective culture against some of the organisms. However, more appropriate quality control measures should be put in place to prevent contamination during nono production.
Key words
Lactobacillus spp., milk, fermentation, protective cultures
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