SOURCE:

Faculty: Biosences
Department: Applied Microbiology And Brewing

CONTRIBUTORS:

Dimejesi, S.A
Odibo, F.J.C;;

ABSTRACT:

Aspects of Microbiology, Physicochemical and Hazard Analysis Critical Control Points (HACCP) of “ogiri” production from creeping melon (Citrullus vulgaris), climbing melon (Cucumeropsis manii), castor oil (Ricinus communis) and fluted pumpkin (Telfairia occidentalis) seeds were studied. The processed and unprocessed samples as well as utensils, packaging materials and water used in the production of “ogiri” from these substrates were analyzed using standard methods. Hazard analysis was carried out at each stage of production. Samples were collected from different States of Nigeria. Microbial isolates were obtained from different sources(raw seeds, “ogiri” produced from the substrates by the local producers, ‘ogiri’ produced in the laboratory, handlers, utensils, packaging materials as well as at each stage of production process). The bacterial and fungal isolates were identified phenetically and by DNA sequencing using 16S rRDNA and ITS rDNA. The physicochemical analyses were carried out using standard methods. The critical control points were determined using decision tree and the result analysed statistically using Analysis of Variance (ANOVA). The mean viable microbial counts of raw and processed samples significantly (P<0.05) increased from 8.3 x 104 – 3.7 x 108cfu/g, 9.5 x 104 – 5.2 x 108cfu/g, 9.8 x 104 – 4.7 x 108cfu/g and 7.6 x 104 – 4.5 x 108cfu/g in climbing melon, castor oil, creeping melon and fluted pumpkin seeds respectively. The average heterotrophic bacterial counts of ‘ogiri’ produced from creeping melon, fluted pumpkin and climbing melon seeds were 4.8 x 108cfu/g, 3.8 x 108cfu/g and 2.7 x 108cfu/g respectively while that of castor oil was 5.6 x 108cfu/g. The mean coliform counts of the leaves, water, mortar and pestle, nasal and skin swabs and strings were 2.5 x 106cfu/ml, 2.1 x 106cfu/ml, 2.4 x 106cfu/ml, 2.8 x 103cfu/ml, 3.3 x 103cfu/ml and 1.2 x 104cfu/ml respectively and the counts are higher than the acceptable limits 104cfu/g and 102cfu/g for heterotrophic bacteria and coliform respectively. Fermentation for six days resulted in a significant (P<0.05) increase in the total bacterial counts of climbing melon, titrable and volatile acid contents, while the total bacterial counts in fluted pumpkin, castor oil and creeping melon seeds increased up to the 4th day and decreased thereafter. The total fungal counts decreased significantly (P<0.05) in all the samples. Seventeen bacterial and five fungal genera were identified and the most pathogenic ones are Staphylococcus aureus, Enterobacter cloacae, Klebsiellapneumoniae and Aspergillusfumigatus. There was significant decrease in the crude fibre, protein and ash contents in virtually all the samples. There was a significant difference (P<0.05) in the amino acid contents of raw and processed samples except proline where the difference was not significant (P>0.05). The total aflatoxin contents were higher in the locally produced samples than in the laboratory samples. The heavy metal contents were higher in the raw than fermented samples. The hazard analysis revealed sorting, washing, fermentation, mixing, boiling and packaging as critical control points. Microorganisms, heavy metals and aflatoxin were identified in locally produced ‘ogiri’. Awareness campaignon production and personal hygiene can help to address food safety problems. Boiling of “ogiri” before use in preparing cold ready-to-eat foods such as “abacha” is recommended.