Abstract:Effects of different conditions (time, mode, temperature and dehydration process) of washing process on microbe of whole leaf Romaine lettuce was evaluated. The results showed that pre-washed help to improve the washing effect. Prolonging the longer washing time and decreasing the temperature within the tested scope led to more efficiency of the washing on reducing the total bacterial count of the salad lettuce. The multi-stage washing showed better effect on reducing the total bacterial count than the continuous washing. Multi-stage washing combined with a 60 s centrifugal drying (reducing the water from surface of lettuce to 3.06%) could significantly improve the efficiency of the further sterilization. The most suitable washing conditions were determined as washing the lettuce at low temperature of 10 ℃ for 60 s twice after pre-wash. The coliform would drop to 75 MPN/g, and the depletion rate of the total bacterial count was 96.64%.
