Mississippi State University
Schilling, M. Wes
Sharma, Chander Shekhar
Mahmoud, Barakat S. M.
Date of Degree
Dissertation - Open Access
Department of Food Science, Nutrition and Health Promotion
Center for Disease Control and Food and Drug Administration reports indicate that cantaloupe is one of the five most likely fruits and vegetables to cause a foodborne disease outbreak. Cantaloupe is a potential hazardous food based on the FDA food code since it is capable of supporting pathogen growth due to its low acidity and high moisture content. The objectives of this study were to determine the effect of strain and temperature on growth and biofilm formation of L. monocytogenes and Salmonella spp. in cantaloupe flesh and peel extracts on different food-contact processing surfaces. Growth of L. monocytogenes and Salmonella strains was greater in high cantaloupe flesh and peel extract concentration at 22°C and 10°C. In 50 mg/ml of cantaloupe flesh or peel extract, the cell numbers of L. monocytogenes and Salmonella increased by 5.0-5.5 log CFU/ml in 40 h at 22°C and 1-3.5 log CFU/ml in 72 h at 10°C. In 2 mg/ml of cantaloupe flesh or peel extract, the cell numbers of L. monocytogenes and Salmonella increased by 4.0-4.5 log CFU/ml in 72 h at 22°C but no change in log CFU/ml in 72 h at 10°C. There were no differences (P ˃ 0.05) among L. monocytogenes orSalmonella strains for biofilm formation in cantaloupe extracts, but biofilm formation was greater (P < 0.05) at high temperature and high cantaloupe flesh or peel extract concentration. In 50 mg/ml cantaloupe flesh or peel extract, L. monocytogenes and Salmonella produced biofilms of 7 log CFU/coupon in 4 days at 22°C and 4-5 log CFU/coupon in 7 days at 10°C. In 2 mg/ml cantaloupe flesh or peel extract, L. monocytogenes and Salmonella produced biofilms of 5-6 log CFU/coupon in 4 days at 22°C and 3-4 log CFU/coupon in 7 days at 10°C. L. monocytogenes and Salmonella spp. formed less biofilms (P < 0.05) on buna-n rubber when compared to stainless steel, polyethylene and polyurethane surfaces. These findings indicate that a very low concentration of nutrients that are leaked from cantaloupe flesh or peel can induce growth and biofilm formation in L. monocytogenes and Salmonella spp. on different food-contact surfaces.
De Abrew Abeysundara, Piumi, "Growth and Biofilm Formation by Listeria Monocytogenes and Salmonella Spp. In Cantaloupe Extracts on Four Food-Contact Surfaces at 22°C and 10°C" (2017). Theses and Dissertations. 2447.