真空预冷过程会导致致病菌渗透至蔬菜气孔的内部，难以用常规清洗方式去除。为了去除渗透至生菜气孔内的大肠杆菌（Escherichia coli）单独清洗剂清洗（CK）作为对照组，利用超声波（US）、真空超声波（VC-US）复合清洗剂对真空预冷后的生菜进行清洗，通过测定清洗前后的菌落数量及相关理化指标在贮藏过程中的变化，评价其对生菜内部E. Coli的清洗效果和品质的影响。结果表明：VC-US处理后，生菜内部的E. coli数量从原始的4.33下降至1.97 log CFU/cm2，优于US和CK组（分别下降至3.03和2.85 log CFU/cm2）（P<0.05）。贮藏2 d后，VC-US组L*值显著高于CK和US组，而a*值和b*值显著低于CK和US组（P<0.05）；VC-US组叶绿素和维生素C的含量略低于CK和US组，但差异性不显著（P>0.05）；此外，VC-US组的失重率（-18.56%）显著低于CK（0.79%）和US（0.16%）组（P<0.05）。综上所述，VC-US处理作为一种复合型处理方式不仅能更有效地去除生菜内部的E. coli，且对品质无显著影响。该研究为蔬菜内部致病菌的去除提供理论依据和应用价值。

Vacuum cooling often results in the penetration of pathogenic bacteria into the stomata of vegetables, hindering their removal using conventional washing methods. A control group (CK) was washed with a cleaning agent alone, whereas experimental groups were subjected to ultrasonic (US) or vacuum-ultrasonic (VC-US) treatment combined with washing with a leaning agent to eliminate Escherichia coli that penetrated the stomata of lettuce after vacuum cooling. The E. coli removal efficiency of these treatments and their impact on lettuce quality during storage were evaluated via measuring bacterial colony counts and key physicochemical indicators before and after treatment. The number of E. coli in the lettuce decreased from 4.33 to 1.97 log CFU/cm² after VC-US treatment, indicating higher removal efficiency than that of the US and CK groups (to 3.03 and 2.85 log CFU/cm², respectively; P<0.05). After two days of storage, the VC-US group had a significantly higher L* value but considerably lower a* and b* values than the CK and US groups (P<0.05). The chlorophyll and vitamin C contents in the VC-US group were slightly, but not significantly, lower than those in the CK and US groups, (P>0.05). Additionally, the weight loss rate in the VC-US group (-18.56%) was significantly lower than those in the CK (0.79%) and US (0.16%) groups (P<0.05). In conclusion, VC-US treatment, as a composite method, effectively removes E. coli from within lettuce and does not significant affect lettuce quality. This study provides a theoretical basis and practical insights for the removal of pathogenic bacteria from within vegetables.

国家自然科学基金面上项目（32272425）；广东省自然科学基金项目（2020A1515011182）；广东省普通高校重点领域专项（2022ZDX4042）；国家级大学生创新创业训练计划项目（202210576017）；广东省大学生创新创业训练计划项目（S202310576037）；韶关市科技计划项目（210724144530340）；韶关学院自然科学基金项目（SZ2020KJ05；SY2023KJ10）；海关总署科研项目（2024HK131）