真空预冷过程中喷雾补水处理对上海青低温流通及货架期品质的影响

目的：探究真空预冷过程中喷雾补水处理对上海青低温流通及货架期间品质的影响。方法：采用真空预冷处理及其与喷雾补水结合共处理上海青，模拟低温流通（（4±1）℃、1 d）和货架销售（（20±1）℃、5 d），并分析流通和货架期间上海青的品质指标和营养指标。结果：与单独真空预冷相比，真空预冷结合喷雾补水不仅使上海青预冷时间缩短了68%，而且使上海青的失水率降低了73.29%，货架结束后质量损失率也降低了15.6%。真空预冷与喷雾补水共处理亦显著延缓了上海青的黄化进程，维持了组织较高的可滴定酸质量分数、可溶性糖含量和可溶性蛋白含量。此外，在货架期最后1 d时，真空预冷与喷雾补水共处理组的亚硝酸盐和丙二醛含量比单独真空预冷组分别降低了13.70%和14.82%。结论：真空预冷过程中喷雾补水既能解决单独真空预冷造成的失水问题，缩短预冷时间；又可延缓采后上海青的黄化衰老进程、维持组织较好的营养品质。

Effect of Atomized Water Spray during Vacuum Pre-cooling on the Quality of Pakchoi during Low Temperature Circulation and the Shelf Life Period

This work aimed to study the effect of atomized water spray during vacuum pre-cooling on the quality of pakchoi during low temperature circulation and the shelf life period. Quality and nutritional parameters of pakchoi subjected to vacuum pre-cooling combined with atomized water spray were analyzed during simulated circulation for one day at (4 ± 1) ℃ and the shelf life period of five days at (20 ± 1) ℃. The results showed that the co-treatment not only decreased the pre-cooling time by 68%, but also reduced the water loss rate of pakchoi by 73.29% and the mass loss rate after the shelf life by 15.6% in comparison with vacuum precooling alone. The co-treatment also delayed the yellowing process, and maintained higher contents of titratable acids, soluble sugars, and soluble proteins in pakchoi. In addition, on the last day of shelf life, the contents of nitrite and malondialdehyde in the co-treatment group were decreased by 13.70% and 14.82%, respectively compared with the vacuum precooling group. To sum up, vacuum pre-cooling combined with atomized water spray could not only solve the problem of water loss caused by vacuum pre-cooling and shorten the pre-cooling time, but also delay the yellowing of leaves and maintain better nutritional quality of pakchoi.