The microbial quality of pre-packed mixed vegetable salad in some retail outlets in Lagos, Nigeria.

Abstract

Pre-packed mixed vegetable salad and salad ingredients- carrots, cucumber, cabbage, and lettuce were analyzed fortheir microbial quality. The salads were obtained from fast food outlets (well packaged at 4 oC) and open markets(exposed at 35oC) within Lagos metropolis. The analysis was both qualitative and quantitative. Microorganismsisolated from salad samples from fast food outlets include Aspergillus fumigatus, Trichoderma spp, Staphylococcusaureus and Proteus mirabilis, while those isolated from open market samples include Mucor spp, A. fumigatus,Aspergillus niger, Trichoderma spp, Neurospora crassa, Proteus vulgaris, S. aureus, Citrobacter freundii, Proteusmirabilis, and Corynebacterium spp. Those from salad ingredients include Mucor spp, A. fumigatus, Trichodermaspp, N. crassa, Rhizopus spp, A. niger, P. vulgaris, P. mirabilis, S. aureus, Pseudomonas aeruginosa and C. fruendii.The total viable count was highest in salad samples from open markets (5.9×106cfu/g) and lowest in salad samplesfrom fast food outlets (2.6 × 104cfu/g). The total viable counts obtained from the salad ingredients were generallylower than those obtained from salads. Among the salad ingredients the highest count was however obtained fromcarrot (3.0 × 102cfu/g) and lowest count from cucumber (1.3 × 102cfu/g). Gentamicin, chloramphenicol,cotrimoxazoleoflaxacin were most effective against the bacterial isolates yielding greater zones of inhibition. Thestorage temperature and the dirty nature of the open markets must have been responsible for the occurrence ofmore microorganisms in salad samples from open markets than those from fast food outlets. The need for safesalad can not be overemphasized.