Effects of Cleaning Methods on Preservation of Two Kinds of Leafy Vegetables

In order to define the effect of cleaning method on storage quality of packed leafy vegetables at 0 ℃and relative humidity between 85%～95%, two sub-species of Brassica chinensis, pakchoi and bok choy were used as experimental materials, whereas the intact vegetables with no cleaning were used as the control. The result showed that the rate of cleaning performance in leaf-cleaning group was significantly higher than that of cleaning whole plant, but etiolation and decay were rather serious after 5 days. Pakchoi was susceptible to rot after cleaning, but the weight loss rate using whole plant ultrasonic cleaning method was only 0.77% on the 5th day of storage with no yellowing and decay of leaves, which was lower than that of the control group. The yellowish rate of whole plant cleaning of bok choy was only 2.2 on the 7th day with the highest score on sensory evaluation. Thereby,the commodity period of the two kinds of cleaned vegetables leaf was recommended within 5 and 7 days respectively.