Abstract:Fresh-cut fruits and vegetables have a short shelf life and are prone to contamination by foodborne pathogens. In this study, fresh-cut lettuce was used as the test material, and based on single factor and orthogonal experiments, the preservation effect of slightly acidic hypochlorous water (SAHW) on fresh-cut lettuce and its influence on storage quality were studied. Using four factors SAHW available chlorine concentration, treatment temperature, treatment time and treatment method, on the basis of single factor experiments, a four-factor three-level orthogonal test was conducted to verify the effect of the best treatment on the sensory quality, total bacterial count, ascorbic acid (Vc) content and Malondialdehyde (MDA) content of fresh-cut lettuce during storage. The results showed that SAHW had a good preservation effect on fresh-cut lettuce, and the influencing factors were the treatment method>treatment time>effective chlorine concentration of SAHW>treatment temperature. The best preservation treatment was shaking and soaking in the SAHW with an effective chlorine concentration of 50 mg/L for 5 min at 15 ℃. Under this treatment, the sensory score was 5.22, the a* value was -2.73, and the total bacterial count was 3.79 lg CFU/mL. This treatment maintained effectively the sensory quality of fresh-cut lettuce during storage. On the 25th day of storage, the total bacterial count was only 0.72 lg CFU/mL (indicating the inhibition of the growth of bacterial colonies), Vc was 14.5 mg/100 g, and the MDA was 0.26 nmol/g, indicating the reduction of Vc loss and MDA accumulation significantly and extension of the shelf life of fresh-cut lettuce. The results provide a scientific basis for SAHW to be used as a preservative agent for fresh-cut lettuce.