桧木醇对采后龙眼果实品质和生理的影响

Effects of hinokitiol treatment on quality and physiology of harvested longan fruits

研究桧木醇处理对采后龙眼果实贮藏过程中品质和生理的影响。将采后龙眼果实浸泡在50μg/m L桧木醇溶液中10 min,晾干后于(25±1)℃下贮藏。贮藏期间定期测定褐变指数、病害指数、果肉自溶指数、VC含量、可溶性固形物(TSS)含量、可定量酸(TA)含量、总酚含量、苯丙氨酸解氨酶(PAL)和多酚氧化酶(PPO)的活性。结果表明:与对照组相比,采后贮藏第4天,处理组和对照组的的褐变指数分别为2.8和4.2;贮藏2 d后,对照组果实病害指数增加较快,而处理组较慢,在第6天,处理组和对照组的病害指数分别为11.46%与37.83%,因此,桧木醇处理明显抑制采后龙眼果实褐变和腐烂。此外,桧木醇处理激活龙眼果实在贮藏期间PAL活性,抑制PPO活性,并保持一定的总酚含量但桧木醇处理并不能显著抑制龙眼果实自溶。同时,能保持较高的可溶性固形物含量和可滴定酸含量,因此,桧木醇处理可以维持采后龙眼果实的品质,延缓果皮褐变。

Effects of hinokitiol treatment on the quality and physiological of postharvest longan fruits were stuided. Postharvest longan fruits were soaked in 50 μg/ml hinokitiol for 10 min. The fruit was then stored at （25 ± 1 ） ℃ after drying. During storage time, pericarp browning index, disease index ,the pulp autolysis index, vitamin C, total soluble solids（TSS） , titratable acid （TA） , total phenolics, the activities of phenylalnine ammonialyase （PAL） and polyphenol oxidase（PPO）were tested. The results showed that browning index of treated fruits and controlled fruit were 2.8 and 4.2 after 4 days respectively; disease index of controlled fruit rapidly increased after 2 days of storage time and was 37.83% at 6 d, but treated fruit rotted slowly and had disease index of about 11.46% at the end of storage time. This shows that the treatments with hinokitiol inhibited browning and rotting of postharvest longan fruit. In addition, the treatment could effectively induced PAL activity, inhibited PPO activity, and maintain total phenol content. However, it can＇t inhibit the autolysis of longan. Meanwhile, the treated fruits had higher contents of TSS and TA than the controlled group. As a result, hinokitiol treatment can be used as an effective preservation to keep quality and delay browning of longan.