Evaluation of biofilm-forming abilities of Listeria monocytogenes (ATCC 19115) and efficacy of different washing methods for removal of biofilm on apple

• Published in: Food Research (Online) Vol. 5; no. 4; pp. 259 - 265
• Main Authors: Ali, Y., Mah, H.Y., Phuah, E.T., Chen, S.N., Yeo, S.K., Kuan, C.S., Radu, Son, New, C.Y., Kuan, C.H., Azizi, P.
• Format: Journal Article
• Language: English
• Published: 08.08.2021
• ISSN: 2550-2166; 2550-2166
• DOI: 10.26656/fr.2017.5(4).037

Fresh produce can be contaminated at any stage along the food supply chain. In this study, apple was chosen to determine the time course of biofilm formation by Listeria monocytogenes (ATCC 19115), as well as to compare the efficacy of different household washing methods such as scrubbing with hands under running tap water, soaking with and without commercial vegetable wash with different treatment times in removing the biofilm formation by L. monocytogenes on apple surface. The biofilm formation was quantified using crystal violet assay and the result showed that L. monocytogenes took 18 hrs to form matured biofilm on apple surface. Besides, scrubbing apples with hands under running tap water for 30 s and 60 s were the most effective method which significantly removed (P<0.05) biofilm formed on the apple surface with approximately 5.93 log reduction. Soaking apples with vegetable wash for 5 mins and 10 mins were also found to be significantly effective (P<0.05) in reducing L. monocytogenes biofilm. Since L. monocytogenes can form matured biofilm on fresh produce, therefore efficient washing step is important before consuming fresh produce to lower the risk of foodborne illness.