Kanchan Chutaprayoonsak. Reduction of Ascaris Suum eggs in lettuce and coriander by using tap water . Master's Degree(Infectious Diseases and Epidemiology). Mahidol University. : Mahidol University, 2003.
Reduction of Ascaris Suum eggs in lettuce and coriander by using tap water
Abstract:
The objective of this experimental research was to compare the quantities of
Ascaris eggs removed from lettuce and coriander when vegetables were washed by using
tap water. Ascaris eggs were dropped on vegetables and examined at 1, 2 and 3 days after
the vegetables were washed and soaked in water with chlorine at soaking times of 1, 3, 5,
10, and 15 min. Ascaris eggs were prepared for dropping on lettuce and coriander in the
ratio of 250 Ascaris eggs in 75 μl of water per 1 lettuce and 1 coriander. Concentrations of
chlorine in tap water were 0, 0.1, 0.2 and 0.5 mg/ L. There were 3 replications. The
vegetables were shaken by hand for approximately 10 seconds (for approximately 13
times). The data were analyzed by 3 - ways ANOVA and Least Significant Difference
Test.
Results showed that the number of eggs was related to the number of days after
Ascaris eggs were dropped onto lettuce, concentration of chlorine in tap water and
duration of vegetable soaking times. One day after Ascaris eggs were dropped onto
lettuce, it was found that a concentration of chlorine 0.5 mg/L in tap water and soaking for
15 min. removed the highest number of Ascaris eggs (p < 0.05). Two days after Ascaris
eggs were dropped onto vegetables, it was found that a concentration of chlorine 0.5 mg/L
in tap water and soaking for 15 min. removed the highest number of Ascaris eggs (p <
0.05). Three days after Ascaris eggs were dropped onto vegetables, it was found that a
concentration of chlorine 0.5 mg/L in tap water and soaking for 15 min. removed the
highest number of Ascaris eggs (p < 0.05).
For coriander, the number of eggs was related to the number of days after Ascaris
eggs were dropped onto coriander, concentration of chlorine in tap water and duration of
vegetable soaking times. One day after Ascaris eggs were dropped onto coriander, it was
found that a concentration of chlorine 0.2 mg/L in tap water and soaking for 10 min.
removed the highest number of Ascaris eggs (p < 0.05). Two days after Ascaris eggs were
dropped onto vegetables, it was found that a concentration of chlorine 0.2 mg/L in tap
water and soaking for 15 min removed the highest number of Ascaris eggs (p < 0.05).
Three days after Ascaris eggs were dropped onto vegetables, it was found that a
concentration of chlorine 0.2 mg/L in tap water and soaking for 15 min. removed the
highest number of Ascaris eggs (p < 0.05).
The conclusion is that the highest clorine concentration and the longest soaking
time removes the highest number of Ascaris eggs in lettuce but a lower concentration
removes the highest number in coriander.