Biological Hazard Evaluation and Management Plan for Safety Improvement of Sandwich Produced in Food Truck

Abstract

The aim of this study was to analyze microbiology hazard of egg mayonnaise sandwiches sold in the food truck and questionnaire survey on the hygienic evaluation of sandwich food truck to provide improvement and management plan for the problem during production process. Therefore, the microbiological hazard evaluation of food materials, the semi-finished products in different processes, environment, tools and employees were analyzed, and questionnaire survey was conducted on food materials in food truck, cooking process, equipment/tools and personal hygiene. In the pre-treated food materials of the egg mayonnaise sandwich, all the total plate count were detected. Staphylococcus aureus and coliforms were detected on lettuce, tomato and egg mayonnaise. The range of total plate count, coliforms, and Staphylococcus aureus was from 2.09±0.24 log CFU/g to 5.18±0.08 log CFU/g, 3.82±0.11 log CFU/g to 5.05±0.04 log CFU/g, 2.24±0.08 log CFU/g to 2.53±0.13 log CFU/g, respectively. There were slicing, filling, and packaging three processes in the food truck due to space limitation. During the packaging process, the total plate count level and Staphylococcus aureus level reached the highest levels of 4.16±0.09 log CFU/g, 4.71±0.20 log CFU/g and 2.36±0.12 log CFU/g. Meanwhile, the result of airborne bacteria detection showed that the total plate count level of airborne bacteria was 4.40±0.57 CFU/plat·15min and no coliforms were detected. And the result of surface contamination detection showed that coliforms were not detected in the surface of processing space, but the 1.40±0.28 log CFU/g~2.01±0.09 log CFU/g of total plate count were detected. And the highest level of total plate count detected on the floor, it may be caused by high level of airborne bacteria. The results of surface contamination of the six kinds of tools used during sandwich production process showed that the range of total plate count level was 1.57±0.10 log CFU/g to 4.11±0.07 log CFU/g, and the range of coliforms level was 1.62±0.10 log CFU/g to 3.47±0.11 log CFU/g. The hygienic index bacteria level of tomato clip was the highest among all tools, it may related to the cross-contamination between food and tools as a result of the fact that lettuce and tomatoes were picked up by one clip successively. Finally, Staphylococcus aureus was detected on the employees’ hand and it was considered as potential risk of causing foodborne diseases. According to the results of questionnaire survey, the sample food truck had refrigerated equipment. However, there were harmful operations during processing which may lead food contamination. And tools such as clip were not used distinctively. And the employees in sample food truck did not wear sanitary clothes, sanitary caps and wearing sanitary masks but jewelry that may lead to cross-contamination. Meanwhile the sample food truck was not equipped with a clear water reservoir and a drainage facility so that employees cannot be cleaned or disinfected before and after the production process, thus it may affect food safety and health. Refer to the results of the microbiological hazard evaluation and questionnaire survey, the sample food truck should strengthen the hygienic management of food materials. And complete different processing in the food truck. A clear water reservoir and a drainage facility should be added. Finally, employees need to pay attention to personal hygiene management and work follow the principles, receive health education regularly so that food truck can ensure food safety and hygiene.