MICROBIOLOGICAL QUALITY AND PROXIMATE EVALUATION OF LOCALLY FERMENTED MILK (NONO) PRODUCED FROM SELECTED LOCATIONS IN MINNA, NIGER STATE

Abstract

‘Nono’ is a locally fermented diary product from cow milk which is common in northern Nigeria. This study was designed to determine the microbiological quality and proximate properties of ‘nono’ produced in three locations in Minna, Niger state. Five samples were collected from different stages of ‘nono’ production (sample collected directly from the udder, after mixing the milk form several cows, after sieving the milk, after fermentation, after churning) from three different location. The samples were cultured on Nutrient, Macconkey and Sabouraud dextrose agar for total bacterial, total coliform and fungal counts respectively using pour plate method. Results revealed that microbial counts in the different stages of ‘nono’ production ranged from 1.00x106±0.00 - 10.50x106±0.50 cfu/mL for total viable count, 1.00x106±0.00 - 7.50x106±0.50 cfu/mL for total coliform count and 1.00x106±0.00 - 1.02x106±0.01 cfu/mL for fungal count. A total of 89 isolates were recorded (A=36, B=31 and C=22). The Bacteria isolated include Klebsiella pneumoniae, Bacillus subtilis, Pseudomonas aeruginosa, Micrococcus luteus, Salmonella enterica, Escherichia coli, Klebsiella aerogenes, Bacillus cereus, Klebsiella oxytoca, Citrobacter freundii, Staphylococcus aureus, Kocuria rosea, and species of Lactobacillus, Streptococcus, Proteus, Lactococcus, Vibrio and Shigella. Klebsiella pneumoniae had the highest frequency 12 (14.63 %) followed by Bacillus subtilis 10 (12.19 %) and pseudomonas aeruginosa 8 (9.76 %) while the lowest frequency of 1 (1.1 %) was recorded for Klebsiella oxytoca, Citrobacter freundii, Kocuria rosea and Vibrio sp. The fungal species isolated include Aspergillus niger, Aspergillus terreus, Aspergillus fumigatus, Trichophyton verrucossum, Torulopsis dottila and Rhizopus arrhizus. The frequency of occurrence of fungal isolates revealed that Aspergillus niger had the highest frequency of (2) 28.60 %. The proximate analysis result showed that the protein values ranged from, 3.35±0.50-6.50±0.21 %, ash content ranged from 0.72±0.02-1.02±0.6 %, moisture content ranged from 81.21±0.1-82.17±0.07 %, total fat ranged from 2.10±0.022.58±0.05 %, and carbohydrate content raged from 9.17±0.22-11.32±0.03 %. The result of the physicochemical analysis revealed that pH values ranged from 4.54±0.054.87±0.02, titratable acidity ranged from 3.46±0.6-3.90±0.70, and viscosity ranged from 134.50±1.40-143.14±0.25 cP. Consumption of ‘nono’ produced in the study area pose potential public health threat due to the presence of pathogenic organisms.