Main Article Content



acetic acid, combined treatments, decontamination, oregano essential oil


This study determined the microbiological quality of lettuce purchased at Durban markets, and evaluated the antimicrobial effects of oregano essential oil (OEO), acetic acid (AA) and combination (OEO+AA)] on the survival of Escherichia coli and L. monocytogenes on lettuce for 6 days. Aerobic and anaerobic spore formers, Staphylococcus aureus, Escherichia coli and L. monocytogenes were microscopically and phenotypically identified from the lettuce. Decontamination was higher and significantly different (p>0.05) at 5ºC with combined 0.3%  AA+0.1%  EOE, and complete inhibition of pathogens was observed on day 2. This formulation can increase antimicrobial efficacy and balance sensory attributes of treated lettuce.

Abstract 257 | pdf Downloads 143


Akbas M.Y. and Olmez H.O. 2007. Inactivation Of Escherichia Coli And Listeria Monocytogenes on Iceberg Lettuce By Dip Wash Treatments With Organic Acids. Letters In Applied Microbiology, 44:619-624.

Beharielal T., Thamaga-Chitja J. and Schmidt S. 2018. Pre-And Post-Harvest Practices Of Smallholder Farmers In Rural Kwazulu-Natal, South Africa: Microbiological Quality And Potential Market Access Implications. Food Control, 92:53-62.

Callejón R.M., Rodríguez-Naranjo M.I., Ubeda C., Hornedo-Ortega R., Garcia-Parrilla M.C. and Troncoso A.M. 2015. Reported Foodborne Outbreaks Due to Fresh Produce In The United States And European Union: Trends And Causes. Foodborne Pathogens and Disease, 12:32-38.

Carella L. 2014. Use Of Oregano Essential Oil and Acetic Acid to Reduce Salmonella Contamination On Romaine Lettuce. Doctoral dissertation, University of Georgia.

De Medeiros Barbosa I., Da Costa Medeiros J.A., De Oliveira K.Á.R., Gomes-Neto N.J., Tavares J.F., Magnani M. and De Souza E.L. 2016. Efficacy Of The Combined Application Of Oregano And Rosemary Essential Oils For The Control Of Escherichia Coli, Listeria Monocytogenes And Salmonella Enteritidis In Leafy Vegetables. Food Control, 59:468-477.

Department Of Health. 2002. Guidelines For Environmental Health Officers On The Interpretation Of Microbiological Analysis Data Of Food (Pp. 1-26). Pretoria, South Africa: Department Of Health, Directorate: Food Control. Annexure B Proposed MicrobiologicalSpecification To Be Used As Guidelines For Foods.

Hirshfield I.N., Terzulli S. and O’byrneC. 2003. Weak Organic Acids: A Panoply Of Effects On Bacteria. Science Progress, 86:245-269.

Huang Y. and Chen H. 2011. Effect Of Organic Acids, Hydrogen Peroxide And Mild Heat On Inactivation Of Escherichia Coli O157: H7 On Baby Spinach. Food Control, 22:1178-1183.

Ijabadeniyi O.A., Debusho L.K., Vanderlinde M. and Buys E.M., 2011. Irrigation water as a potential preharvest source of bacterial contamination of vegetables. Journal of Food Safety, 31:452-461.

Jordaan M. 2013. The prevalence and characterisation of Escherichia coli on fresh produce from selected farms, retail outlets and markets in the Western Cape. PhD Dissertation. Stellenbosch: Stellenbosch University, 2013.

Korir R.C., Parveen S., Hashem F. and Bowers J. 2016. Microbiological Quality Of Fresh Produce Obtained From Retail Stores On The Eastern Shore Of Maryland, United States Of America. Food Microbiology, 56:29-34.

Merlini V.V., Pena F.D.L., Da Cunha D.T., De Oliveira J.M., RostagnoM.A. and Antunes A.E.C. 2018. Microbiological Quality Of Organic And Conventional Leafy Vegetables. Journal Of Food Quality, 2018.

Miyague L., Macedo R.E.F., MecaG.,Holley R.A. and Luciano F. B. 2015. Combination Of Phenolic Acids And Essential Oils Against Listeria Monocytogenes. Lwt -Food Science And Technology, 64:333-336.

Murray K., Wu F., ShiJ., Jun Xue S. and Warriner K. 2017. Challenges In The Microbiological Food Safety Of Fresh Produce: Limitations Of Post-Harvest Washing And The Need For Alternative Interventions. Food Quality And Safety, 1:289-301.

Nazer A.I., Kobilinskyb A., Tholozana J.L. and Dubois-Brissonnet F. 2005. Combinations Of Food Antimicrobials At Low Levels To Inhibit The Growth of Salmonella Sv. typhimurium: A Synergistic Effect? Food Microbiology, 22:391-398.

Park S.H., Choi M.R., Park J.W., Park K.H., Chung M.S., Ryu S. and Kang D.H. 2011b. Use Of Organic Acids To Inactivate Escherichia Coli O157: H7, Salmonella typhimurium, And Listeria monocytogenesOn Organic Fresh Apples And Lettuce. Journal of Food Science, 76.

Pingulkar A.K. and Dilip Bongirwar K. 2001. Microbiological quality of fresh leafy vegetables, salad components and ready-to-eat salads: an evidence of inhibition of Listeriamonocytogenesin tomatoes. International Journal of Food Sciences and Nutrition, 52(1):15-23.

Ponce A.G., Del Valle C. and Roura S.I. 2004. ShelfLife Of Leafy Vegetables Treated With Essential Oils. Journal of Food Science, 69.

Raeisi, M., Tajik, H., Yarahmadi A. and Sanginabadi S. 2015. Antimicrobial Effect Of Cinnamon Essential Oil Against Escherichia coli And Staphylococcus AUREUS. Health Scope, 4.

Samara A. and Koutsoumanis K.P. 2009. Effect Of Treating Lettuce Surfaces With Acidulants On The Behaivour Of Listeria Monocytogenes During Storage At 5ºC And 20 ºC And Subsequent Exposure To Simulated Gastric Fluid. International Journal of Food Microbiology, 129:1-7.

Singh N., Singh R.K., Bhunia A.K. and Stroshine R.L. 2002. Effect Of Inoculation And Washing Methods On The Efficacy Of Different Sanitizers Against Escherichia Coli O157: H7 On Lettuce. Food Microbiology, 19:183-193.

Solgi M. and Ghorbanpour M. 2014. Application Of Essential Oils And Their Biological Effects On Extending The Shelf-Life And Quality Of Horticultural Crops. Trakia Journal Of Sciences, 12:198-210.

Topali?-Trivunovi? L., Savi? A., Kova?evi? J., Baleševi? L., Matoš S. and Šolaja, M. 2014. The Microbiological Status Of (Ready To Eat) Lettuce Before And After Standard Washing. Hemi?ara, Tehnologa I Ekologa,10:51-56.

Wiederoder M.S., Lefcourt A.M., Kim M.S. and Lo M.Y. 2012. Detection Of Freshcut Produce Processing Residues On Food Contact Surface Materials Using Hyperspectral Imaging. Journal Of Food Measurement And Characterization, 6:48-55.

Zhou F., Ji B., Zhang H., Jiang H., Yang Z., Li J., Li J., Ren Y. and Yan W. 2007. Synergistic Effect Of Thymol And Carvacrol Combined With Chelators And Organic Acids Against Salmonella Typhimurium. Journal Of Food Protection, 70:1704-1709.