The Prevalence of Bacterial Pathogens in Vegetable Salads and Juices in Urban West Region of Zanzibar, Tanzania

Abstract

Fruit juices and vegetable salads are the most common street foods vended in developing countries. Improperly processed juices and vegetables can cause food borne illnesses, which is a long-standing problem in Zanzibar. The study’s objective was to determine the bacterial quality in the vegetable salads and juices in Zanzibar. The cross-sectional design that involved field sampling of juices and vegetables was used. Bacteriological analysis was performed using standard techniques of culturing in designated media. The investigated samples were mango juice (n= 49), tamarind juice (n= 49), and vegetable salads (n= 98). One-way analysis of variance (ANOVA) was used to compare the mean bacterial counts between tamarind and mango juice as well as bacterial counts in salads. The result of this study revealed that 88/98 (89.7%) of salad samples had high counts of E. coli with colony-forming units between 2.7 × 102 to 7.8 × 103 and E. coli contamination levels of 55% (27/49) in tamarind juice and 30/49 (61%) in mango juice respectively. Salmonella Typhi was found in two samples of mango juice but none in tamarind juice and salad. The overall E. coli contamination level in all juices was 58%. Average Most Probable Number (MPN) of coliforms in tamarind and mango juice were 450.48 MPN/m and 952.08 MPN/ml, respectively. Comparatively, mango juice is more contaminated than tamarind juice. The majority of the juice and salads in the study were found to be severely contaminated, which implies that there was inadequate handling and hygiene during the food processing process. Health authorities should keep a close eye on the quality of food being sold on the streets.