Screening of sanitizer for foodborn pathogens in fresh-cut onions and the optimization of the sanitizing condition

Effectiveness of multiple chemical sanitizers on reducing the food borne pathogens in fresh-cut onions was investigated to improve the food safety of fresh-cut vegetables.Fresh-cut onions were inoculated with food borne pathogens, then the inoculated onion dices were treated with water, sodium hypochlorite (200mg/L) , chlorine dioxide (10mg/L) , hydrogen peroxide (20.0g/L) , acidized sodium chlorite (1.0g/L) , peroxyacetic acid (80mg/L) , citric acid (10.0g/L) , lactic acid (10.0g/L) , and lactic acid at 55℃ (10.0g/L) for 3min respectively .The result showed acidified sodium chlorite produced a 3.19log CFU/g reduction for E.coli O157∶H7, a 3.11log CFU/g reduction for Listeria monocytogenes and a 2.60log CFU/g reduction for Salmonella typhimurium, achieving the best effect.To optimize the disinfection conditions, response surface experiment was applied and Listeria monocytogenes was taken as the research object, and the optimized treatment was 1.0g/L acidized sodium chlorite solution, rinsing for 2min.Assessing the effect of the acidized sodium chlorite on the fresh-cut onions found that acidized sodium chlorite treatment followed by water wash could keep desirable sensory quality.