O_2和CO_2配比对气调贮藏梨采后褐变及相关理化因子的影响

Postharvest Physiological Brown of Hosui Pear Stored in Different O_2 and CO_2 Composition Conditions

以采后丰水梨果实为材料,在乐扣气调试验箱中研究了O2和CO2配比对果实褐变率、多酚氧化酶(PPO)和过氧化物酶(POD)活性、丙二醛(MDA)和总酚含量的影响,以探讨适宜减轻梨气藏褐变的气体成份.结果表明:在整个贮藏过程(150d)中,丰水梨果肉未发生褐变.从贮藏60d开始,气调处理和冷藏对照果实的果皮均出现褐变,气调处理在贮藏120d之前对果皮褐变的影响不显著,而在贮藏120～150d内可显著减轻果皮的褐变、抑制果皮PPO和POD活性及降低总酚含量.与冷藏对照相比,气调处理可推迟果心褐变的时间,且(8%～10%)O2+3%CO2处理可完全抑制果心的褐变;气调处理亦可降低果心PPO活性、减少总酚及MDA含量;(8%～10%)O2+1%CO2处理能够显著提高果心的POD活性,而(8%～10%)O2+3%CO2处理对果实POD活性的影响不显著.可见,气调贮藏主要是通过降低丰水梨果皮PPO、POD活性及总酚含量来减轻组织的褐变,并以(8%～10%)O2+3%CO2处理对果实褐变因子的控制效果较理想.

Activities of two enzymes（peroxidase,polyphenol oxidase）,and contents of malonaldehyde and total phenol of Hosui pear stored in different gas compositions were investigated to seek a effective measure,which could reduce brown of Hosui pear.Results showed no browning symptom appeared in fruit flesh during the whole storage （15 d）.Peel of controlled atmosphere（CA）treatment and refrigerated fruits appeared browning symptom from 60 days of storage,no significant differences were observed in CA and refrigerated treatments for peel browning before 120 days of storage,while CA treatments could significantly alleviate the peel browning,inhibit PPO and POD activities and reduce total phenol content of fruit peel during 120～150 days of storage.CA treatment could postpone the time of core browning of fruit,and the CA storage at （8%～10%）O2＋3% CO2 could inhibit core browning of fruit completely,in comparison with cold storage.CA treatment could also reduce PPO activity,decrease malonaldehyde and total phenol content of fruit core.The controlled atmosphere treatment of （8%～10%）O2＋1% CO2 increased POD activity of fruit core,while the effect of （8%～10%）O2＋3% CO2 treatment on POD activity were not significant.Therefore,controlled atmosphere storage alleviated organizational brown mainly through reducing activities of PPO,POD and total phenol content of fruit peel of Hosui pear,and the treatment of （8%～10%）O2＋3% CO2 were more effective for controlling browning relative factors.