A Preliminary Study on Microbial Contamination of Leafy Vegetables in Sokoto Metropolis, Nigeria

Five leafy vegetables commonly consumed in Sokoto metropolis were evaluated for microbiological quality using standard procedures involving standard plate count (SPC). The vegetables investigated included Lactuaca sativa (Lettuce), Amaranthus hybridus (Spinach), Vernonia amagdalina (Bitter leaf), Brassica oleracea (Cabbage) and Moringa oleifera Lam (Horse radish). Ten fungal species which include Alternaria alternata, Absidia corymbifera, Aspergillus Niger, A. flavus, Cladosporium herbarum, Fusarium oxysporium, Geotrichum candidum, Mucor racemoses, Rhizopus stolonifer and Trichoderma harzianum and four species of bacteria: Bacillus cereus, Escherichia coli, Listeria monocystogens and Staphyllococus aureus were isolated from the leafy vegetables. The total colony counts of fungi ranged from 1.8 x 106 – 6.28 x 105 (cfu/g) of the vegetables while that of bacteria ranged from 1.0 x 106 to 2.94 x 106 cfu/g of the vegetables. The highest counts of microbial organisms were found on A. hybridus while M. oleifera and B. olerarea had the lowest fungal and bacterial counts respectively. There is a need to reduce the levels of microbial contamination on leafy vegetables through appropriate production practices, careful handling by the vendors and appropriate processing with a view to minimize the risk of human exposure to fungal and bacterial pathogens associated with the vegetables

Qualitative And Quantitative Phytochemical Screening Ofcola Nuts (Cola Nitida And Cola Acuminata)

A study was carried out to evaluate the phytochemical constituent ofaqueous and methanol nut extracts of Colanitida and Colaacuminata. The phytochemical screening which involves both the qualitative and quantitative analysis revealed the presence of secondary metabolites; alkaloid, tannins, glycoside, steroids and saponins glycoside with higher contain in methanol and aqueous extracts. The saponins content is higher in the aqueous extract  and not detected in the methanol extract of the two species. Flavonoids expressed strong presence in methanol extract of C.nitida and not detected in the aqueous extract as well as the aqueous and methanol extracts of C. acuminata. For cardiac glycoside and volatile oil, they show moderate and trace presence in the methanol and aqueous extracts respectively. Anteraquinones are not detected in all the extracts of the two species. The quantitative result shows that, there were significant differences (p<0.05) in glycoside, tannins, saponins and alkaloid content of C. acuminata compared to C.nitida, withC. acuminata having the highest percentage of alkaloid (1.00%) while C. nitidahad (0.80%) alkaloid content,C. acuminatahad (0.80%) saponins, with C. nitida having (0.40%), more over the tanninscontent of C. acuminatawas higher (0.89%) compared to C. nitidawith (0.77%) while the glycoside content of C. acuminatawas (0.53%) and that of C. nitida was (0.43%). The results as indicated above disclose the scientific basis for the traditional uses of cola nut. Finally, the study  recommend the isolation of these metabolites using highly purify methods in other  to obtain their maximum therapeutic potentials. Keywords:Colanitida, Cola acuminate,Qualitative and Quantitative PhytochemicalScreening