Microbiological Status and Food Safety Compliance of Commercial Basil Production Systems

Abstract

Basil has been implicated in a number of microbe-associated foodborne illnesses across the world, and the source of contamination has often been traced back to the production and/or processing stages of the supply chain. The aim of this study was to evaluate the microbiological quality of fresh basil from the point of production to the retail outlet in the Gauteng and Northwest Provinces of South Africa. A total of 463 samples were collected over a 3-month period from two large-scale commercial herb producing and processing companies and three retail outlets. The microbiological quality of the samples was assessed based on the presence or absence of Escherichia coli O157:H7 and Salmonella Typhimurium and the levels of the indicator bacteria E. coli and total coliforms. Salmonella Typhimurium was detected on four basil samples (0.9%) arriving at the processing facility and at dispatch, but no E. coli O157:H7 was detected throughout the study. Total coliform counts were 0.4 to 4.1 CFU/g for basil, 1.9 to 3.4 log CFU/ml for water, and 0.2 to 1.7 log CFU/cm(2) for contact surfaces, whereas E. coli was detected in the water samples and only once on basil. The Colilert-18 and membrane filter methods were used to analyze water samples, and a comparison of results revealed that the Colilert-18 method was more sensitive. Strong evidence suggests that high numbers of coliforms do not necessarily indicate the presence of Salmonella Typhimurium. The study results highlight the importance of effective implementation of food safety management systems in the fresh produce industry.