The effectiveness of water, salt and vinegar in reducing the bacteria population in fresh green cabbage

Abstract

Green cabbage has great nutritional and therapeutical values and is usually used as the main ingredient for preparing fresh vegetable salad for consumption. The aim of this work was to identify the bacteria population in different sections of green cabbage heads obtained from some selected markets in Accra and also to determine the most appropriate method for washing to reduce the bacteria population prior to consumption. In the investigation, samples were obtained from five open markets in the Greater Accra Region of Ghana. Fresh leaves taken from the outer, middle and inner sections of the samples were analyzed for aerobic mesophilic organisms, coliforms and Escherichia coli. They were then washed with tap water, 5% salt solution or 50% vinegar solution for five minutes, and the effectiveness of the treatments in reducing the bacteria population determined. Results from the analysis showed that the outer sections of fresh green cabbage heads had high microbial load followed by the middle sections whilst the inner sections were almost sterile. The aerobic mesophilic counts ranged from 106–108 CFU/g for the untreated outer section of the samples, 104–106 CFU/g for the untreated middle sections, and 101–102 CFU/g for the untreated inner sections. Coliforms ranged from 104–106 CFU/g for the untreated outer section of the samples, 102–104 CFU/g for the untreated middle sections and 101 CFU/g for the untreated inner sections. E.coli ranged from 102–103 CFU/g for the untreated outer section of the samples and 101 CFU/g for the untreated middle sections. E. coli was however not detected in the untreated inner sections of the cabbage heads analyzed. The pathogens Bacillus cereus and Staphylococcus aureus were also identified on the samples from the five markets. The treatment with 50% vinegar solution was most effective in reducing the bacteria population on the samples analyzed followed by 5% salt solution and tap water the least effective. The outcome of this work serves as a basis for creating awareness against the use of ordinary tap water by caterers and promote the use of vinegar or salt solutions as a means of reducing bacteria population in freshly served cabbages