论文以整叶罗马生菜为研究对象，研究了不同清洗时间、清洗方式、清洗温度及脱水工艺对色拉生菜微生物的影响。实验结果表明，清洗前的预洗有助于提高清洗效果；在一定范围内，清洗时间越长、温度越低，越能有效降低色拉生菜的大肠菌群数及菌落总数；多级清洗的效果明显优于连续清洗，且由生菜上及洗脱至水中的微生物数量可知，二级清洗已基本将易洗脱的微生物清洗下来；洗完采用离心甩干的方式脱水60 s，减少附着在生菜叶片表面的水膜，使表面附着水量降低至3.06%，再进行消毒，可有效提高后续的消毒效果。可行且较合适的清洗工艺条件为：生菜预洗后进行低温（10 ℃）二级清洗，每级均为震荡清洗60 s，大肠菌群可降低至75 MPN/g，菌落总数减少率达到96.64%，清洗后离心甩干60 s再进入消毒阶段。

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%.

“广东省天然产物绿色加工与产品安全重点实验室”资助项目（2010A060801004）