本文利用冷库(0±2 ℃)预冷、真空预冷及真空预冷恒压（达到终温后，继续在真空状态下维持0、2、4、6 min）等技术对经复合护色液浸渍后的鲜切莲藕进行预冷（预冷终温5 ℃），预冷后采用气调包装并放置于5±2 ℃冷库贮藏。通过测定其贮藏过程中的理化、生化指标来评价不同预冷方式对鲜切莲藕品质的影响。结果表明，真空预冷对鲜切莲藕的降温速率几乎为冷库预冷速率的10倍。随着真空预冷恒压时间的延迟，其水分损失呈增加的趋势，同时差异性显著(P＜0.05)，但对莲藕的外观差异并不显著(P＞0.05)。真空预冷至5 ℃并维持2、4、6 min所获得的理化、生化及营养指标值较对照组而言更接近新鲜莲藕，特别是其不仅能够降低多酚氧化酶(PPO)的最大峰值，同时还能够推迟峰值出现的时间。其中，真空预冷至5℃并维持4 min效果最佳。

Different technologies, including cold storage room pre-cooling, vacuum pre-cooling, and vacuum pre-cooling coupled with constant pressure treatment (when the final temperature was reached, the vacuum pump and valve were closed for 0, 2, 4, and 6 min, respectively), were utilized to pre-cool (final pre-cooling temperature: 5 ℃) fresh-cut lotus root that was impregnated in the compound fresh-keeping solution for 12 min. After pre-cooling, all samples were packaged in a modified atmosphere and stored in the cold storage room (5 ± 2 ℃). The effects of different pre-cooling methods on the quality of fresh-cut lotus root were evaluated by measuring the physiochemical and biochemical indexes during the storage. The experimental results showed that the cooling rate of vacuum pre-cooling was almost ten times that of cold room pre-cooling. In the cooling process when a constant pressure was maintained for a long duration, a significant trend towards increased water loss was observed (P < 0.05), while no significant difference was observed in the overall appearance (P > 0.05). The physicochemical and biochemical indexes obtained for the fresh-cut lotus root that was vacuum pre-cooled to 5 ℃ followed by maintenance at constant pressure for 2, 4, and 6 min were similar to that of the fresh lotus roots than that of the control group. In particular, vacuum pre-cooling coupled with constant pressure treatment not only reduced the maximum peak value of polyphenol oxidase (PPO) activity, but also prolonged the time to reach such a peak value. The best preservation effect was achieved when the sample was vacuum pre-cooled to 5 ℃ and constant pressure was maintained for 4 min.

国家自然科学基金项目(31101215)；广东省高等学校高层次人才项目(粤财教[2013]246号)；韶关市科技计划项目 2013CX/K51 ；国家级大学生创新创业训练项目（201310576-004）