Onyinye Theresa ANOCHIE

This research was undertaken in order to investigate the bacteria associated with locally processed juices and screen for their sensitivity to antibiotics and chitosan. Tigernut milk, zobo and ginger lemon juice samples were purchased from three (3) different shopping malls in Benin City and transported to the laboratory for bacteriological analysis using pour plate isolation method. Susceptibility of bacteria to antibiotics was carried out using disc diffusion method. Antimicrobial activity of chitosan against isolated organisms was carried out using agar well diffusion method. Total bacterial count on nutrient agar ranged from 13.5×10 3cfu/ml for zobo drink (ZN) to 114×10 3cfu/ml for tigernut milk (TNMFJ). On eosin methylene blue agar, total bacterial count ranged from 5×10 3cfu/ml for zobo drink (ZN) to 52×10 3cfu/ml for tigernut milk (TNMN). Organisms isolated include Lactobacillus fermentii, Staphylococcus spp and Salmonella spp. While Lactobacillus fermentii was the least prevalent (60%), Salmonella spp was the most prevalent (100%). The pH ranged from 3.56 in zobo drink (ZN) to 4.78 in tigernut milk (TNMFJ). Tigernut milk (TNMF) had the highest value of total dissolved solids (2.27mg/ml) while ginger lemon juice (GLN) had the least (0.10mg/ml). The titratable acidity of juice samples ranged from 0.02mg/L in zobo juice (ZN) and ginger lemon juice (GLN) to 0.48mg/L in tigernut milk (TNMFJ). The bacterial isolates showed various levels of sensitivity and resistance to a variety of ten (10) antibiotics. Antimicrobial effects of chitosan against Staphylococcus spp and Salmonella spp showed that Salmonella spp was more susceptible to chitosan at a concentration of 25mg/ml. The results indicate that locally processed juices were contaminated with bacterial isolates and should be subjected to good manufacturing practice (GMP). The inhibitory effect of chisotan show it as a potential preservative in food.