Abstract: This study aimed to investigate the effect of atomized slightly acidic electrolyzed water (SAEW) treatment during vacuum precooling on the quality of Chinese little greens during low temperature circulation and shelf life. The effects of vacuum precooling, vacuum precooling combined with tap water treatment and vacuum precooling combined with SAEW treatment on the appearance quality, nutritional components, antioxidant substances and free radical scavenging capacity of Chinese little greens were analyzed under low temperature ((4 ± 1) ℃) distribution and shelf conditions ((20 ± 1) ℃). The results showed that vacuum precooling + tap water treatment could slow down the yellowing and wilting, maintain higher nutritional quality and antioxidant capacity of Chinese little greens when compared to the control (without vacuum precooling or spraying tap water) and vacuum precooling groups. Furthermore, compared to vacuum precooling + tap water treatment, vacuum precooling + SAEW treatment could delay the yellowing and ageing process, suppress the decline in sensory quality and chlorophyll content, maintain higher titratable acid, soluble protein and soluble sugar contents, and retard the decrease in the contents of bioactive substances such as carotenoids, ascorbic acid, folic acid and total phenols and free radical (1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radial and superoxide anion radical) scavenging capacity, thereby inhibiting the accumulation of nitrite and malondialdehyde and prolonging the shelf life of postharvest Chinese little greens. It is thus clear that the combination of vacuum precooling with SAEW treatment can effectively relieve the yellowing and ageing process of postharvest Chinese little greens and maintain good commodity characteristics.

Key words: Chinese little greens; vacuum precooling; slightly acidic electrolyzed water; quality; antioxidant capacity