Behavior of thirteen foodborne bacteria on whole Hass avocado and potential of roselle calyx extracts as alternative disinfectant agents of avocado

The behavior of thirteen foodborne bacteria onto whole Hass avocado and the antibacterial effect of Hibiscus sabdariffa calyx extracts, sodium hypochlorite, acetic acid, and colloidal silver against foodborne bacteria on contaminated avocado were investigated. Avocados were inoculated with foodborne bacteria: Listeria monocytogenes, Shigella flexneri, Staphylococcus aureus, Salmonella Typhimurium, S. Typhi, S. Montevideo, Escherichia coli O157:H7, non-O157:H7-Shiga toxin-producing E. coli, enteropathogenic E. coli, enterotoxigenic E. coli, enteroinvasive E. coli, enteroaggregative E. coli, and Vibrio cholerae O1. The antibacterial effect of four roselle calyx extracts (water, methanol, acetone, and ethyl acetate), sodium hypochlorite, colloidal silver, and acetic acid against all foodborne bacteria were examined onto avocados. All foodborne bacteria successfully attached and survived onto avocado at least 20 days. The acetonic and methanolic roselle extracts caused a greater reduction (until 4-log(10) in some cases) in the concentration of all foodborne bacteria than sodium hypochlorite, colloidal silver, and acetic acid on contaminated avocados. Practical applicationsHass avocado have been associated with foodborne disease caused by Salmonella. The sodium hypochlorite and colloidal silver solution are widely used to disinfect fruit and vegetables in restaurants and home in Mexico. Even, the Health Secretariat of Mexico promotes their use as disinfectants of fruit and vegetables. However, a number of studies have shown that chemical agents used to eliminate pathogenic bacteria on fruits have a limited antimicrobial effect. Roselle calyx extracts are reported to have an antimicrobial effect. This study provides information on the significant impact of acetone and methanol roselle calyx extracts may be a potentially useful addition to disinfection procedures of avocado in the field and processing plants.