Efficacy of chlorine and acidified sodium chlorite on microbial population and quality changes of spinach leaves
Posted: June 18th, 2009 - 7:15pm
Source: Foodborne Pathogens and Disease June 2009, Vol. 6, No. 5: 541-546.
Efficacy of washing with distilled water, chlorine solution, and acidified sodium chlorite (ASC) solution on populations of microorganisms on spinach leaves was evaluated. Washing with chlorine (100mg/L) and ASC (sodium chlorite, 15mg/L; citric acid, 200mg/L) resulted in significant population reduction (1.1–1.9 log CFU/g) of aerobic microflora, coliform, and Escherichia coli O157:H7 (p<0.05). There was no remarkable difference in decontamination efficacy between chlorine and ASC solution. In recent years, several sodium chlorite chemicals have been commercially available, and no difference in decontamination efficacy among the chemicals was observed when same concentration of sodium chlorite and citric acid were used. In addition, the reduction of E. coli O157:H7 population was influenced depending on the inoculation method and type of washing. It has been seen that dip-inoculated spinach leaves showed lower reduction than that of spot-inoculated spinach. After washing, populations of aerobic microflora, coliform, and E. coli O157:H7 were increased during storage at 10°C, and washing condition before storage did not affect the subsequent increases in microbial population. Color of spinach leaves washed with ASC solution was not different from the color of those washed with water or chlorine solution, and washing with ASC solution was concluded to has no effect on appearance of spinach leaves.