Green leafy vegetables are consumed fresh or dried by human beings as good sources of food rich in nutritional quality including beta-carotene, minerals, fibers, which play significant physiological role in human body including stimulating enzymes, reducing diseases like diabetes, destroying bacteria like Salmonella species, Escherichia coli. The aim of the study is to evaluate the bacteriological load in Moringa oleifera Lam. leaves consumed in guinea savannah Vegetation zones of Nigeria, via: Abuja (Gwagwalada market), in Southern guinea savannah, Katsina (Daura market), in Northern guinea savannah and Sokoto (Central market), in Sudan guinea savannah. Three fresh and dried Moringa oleifera Lam. leafy samples each 50 grams were randomly collected per market location for analysis of total viable cells (cfu/mL) using standard procedures of analyses. Bacterial load in each sample was determined in triplicates and analyzed with SPSS Version 16. Bacterial isolates were classified on the basis of cultural morphology, Gram reaction and Biochemical tests. Results showed there was bacterial growth on Nutrient, Mannitol, MacConkey media. Sabouraud dextrose, Brilliant green, Salmonella- Shigella media recorded no growth in all the leave extracts analyzed. This could be ascribed to the selective nature of Sabouraud dextrose, Brilliant green, Salmonella- Shigella media, and suggested that fungi/yeast, Salmonella species, Salmonella-Shigella species were not among the bacterial contaminants or that the active ingredient component-Pterygospermin, in Moringa oleifera leaves extract inhibited the growth of micro-organisms in the leaves extract. The bacterial load in the dried leave extracts increased by 86.70 – 88.96% compared with the fresh leave extracts. The highest viable cell count (12.2 x 104±6.95 cfu/mL) was recorded by Katsina dried leave, west of the market; while the lowest microbial load (1.0 x 104±0.68 cfu/mL) was reported by Katsina and Sokoto fresh leave extracts. The study recorded two pathogenic bacteria from all the locations, with Staphylococcus aureus being more dominating, followed by Escherichia coli. Organisms are indicator for poor hygienic conditions suggesting health hazards. Consumers and vegetable vendors should be educated on proper hygienic handling, transportation and storage of vegetables to avoid bacteriological food spoilage and other related health issues.
Keywords: Moringa oleifera leaves, Nutritional quality, Bacteriological load, Vegetables