不同预冷方式对荔枝贮藏品质的影响

Effect of Different Precooling Methods on the Storage Quality of Litchi

摘要:

为掌握荔枝不同预冷方式对贮藏品质影响，以“淮枝”荔枝为材料，分别采用冰水（L1）、冷库（L2）、差压（L3）以及高湿差压预冷（L4）处理，而后进行25 d保鲜试验，分析并对比不同预冷方式对荔枝贮藏后质量影响。结果表明：保鲜时间延长，荔枝质量损失率不断提高但均未超过1.5%。从5 d至25 d，L1、L2所得好果率从99.33%、53.29%分别降至15.70%、5.29%，L3、L4 10 d后几乎无好果；L1、L2、L3和L4褐变指数分别从1.32、2.42、3.37、3.02升至2.97、3.94、4.18、3.97；同一时期，L1所得好果率和褐变指数明显优于其它方式。前10 d，L1所得色差值明显大于其它预冷方式；L3、L4感官评定无显著性差异，但均明显低于L1。各预冷方式可溶性固形物（TSS）含量在16.63至17.93之间且无显著性差异，并表现出先增后降再增趋势；可滴定酸（TA）含量不断减少。基于对比结果，冰水预冷是荔枝较适合预冷方式。本文为荔枝预冷方式选择提供参考。

Abstract:

In order to obtain the effects of different precooling methods on the storage quality of Litchi, continuous 25 days fresh keeping experiment for “Huaizhi” precooled by ice precooling (L1), room precooling (L2), forced-air precooling (L3) and forced-air precooling with high humidity (L4) was carried out. The analysis and comparison of different precooling methods on the quality of Litchi were conducted. The results showed that the mass loss rate of Litchi pretreated by the four methods increased with time till not more than 1.5%. From the fifth day to the twenty fifth day, the good fruit rates of L1 and L2 decreased from 99.33% and 53.29% to 15.70% and 5.29%, respectively, but L3 and L4 almost had no good fruits after 10 days. The browning indexes of L1, L2, L3 and L4 increased from 1.32, 2.42, 3.37 and 3.02 to 2.97, 3.94, 4.18 and 3.97 respectively. The color difference of L1 was significantly larger than those used other three methods before 10 days. There was no significant difference for L3 and L4 in sensory evaluation, but obvious lower sensory qualities of the L3 and L4 than L1 was found. The soluble solids (TSS) content for the four methods were within 16.63 and 17.93, with tendency of increasing first, then decreasing but increasing again. The titratable acid (TA) content declined with the storage time.Hence, L1 is more suitable for precooking Litchi based and this research can facilitate the selection of precooling method for Litchi.