Efficacy of chlorine and acidified sodium chlorite on microbial population and quality changes of spinach leaves.
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 (100 mg/L) and ASC (sodium chlorite, 15 mg/L; citric acid, 200 mg/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 degrees 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.
National Food Research Institute, Kannondai, Tsukuba, Japan.
Daisuke
D
Nei
Ji-Weon
JW
Choi
Md Latiful
ML
Bari
Susumu
S
Kawasaki
Shinichi
S
Kawamoto
Yasuhiro
Y
Inatsu
D002712:Chlorides / Q000008:administration & dosage*; D002713:Chlorine / Q000008:administration & dosage*; D019343:Citric Acid / Q000008:administration & dosage; D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods; D019453:Escherichia coli O157 / Q000187:drug effects / Q000302:isolation & purification; D005511:Food Handling / Q000379:methods*; D005519:Food Preservation / Q000379:methods; D006863:Hydrogen-Ion Concentration; D018515:Plant Leaves / Q000382:microbiology; D011786:Quality Control; D012996:Solutions; D018724:Spinacia oleracea / Q000382:microbiology*; D014867:Water
D002712:Chlorides; D012996:Solutions; D014867:Water; D019343:Citric Acid; D002713:Chlorine; C001599:chlorite