Effect of washing agents on the bacterial quality of lettuce and cabbage sold in wukari market Taraba state, Nigeria.

Vegetables while growing may be exposed to many sources of contamination like contaminated sewage water used in watering the gardens from where these vegetables are grown. This study was conducted to determine the general bacterial quality of lettuce and cabbage and the effects of washing agents at different contact time so as to establish its microbiological safety. Cabbage and lettuce vegetables were weighed (5grams) each and washed in 250 ml solutions of vinegar, sodium chloride, sterile distilled water, and potable water. The volume of vinegar and quantity of sodium chloride used was 2 ml, 4 ml and 7 ml/g and 2g, 4g and 7g/ ml at < 1 minute, 2 minutes and 5 minutes contact time respectively. In the case of sterile distilled water, and potable water only contact time of 5 minutes was assessed. The results of the total aerobic plate count of bacterial cells ranged from 3.0x107 to 9.2x107cfu/ ml in lettuce and 3.2x107 to 6.9x107cfu/ ml in cabbage. Effect of different contact time for lettuce and cabbage showed some coliform counts for samples treated with sodium chloride at concentrations of (2g) in less than 1 minute and potable water at 5 minutes (4.3x107, 3.0x107, and 4.7x107 cfu/ ml) respectively. However, the samples treated with vinegar, sodium chloride and sterile distilled water at various concentrations of 4 and 7 ml with a contact time of 2 and 5 minutes showed zero coliform count. The following bacteria were isolated from the vegetable samples; Proteus vulgarius, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Salmonella typhi, Enterobacter aerogenes, Staphylococcus aureus, and Pseudomonas aeruginosa which could be due to natural flora in the soil or contaminants. The findings of this study revealed the efficiency of vinegar which had a significant effect on the microbial load reduction amongst the various washing agents used.in relation to the different contact time. Therefore, lettuce and cabbage should be washed in solutions of vinegar / sodium chloride so as to ensure safety of the consumers.