减压贮藏对去壳黄甜竹笋的保鲜效果及其生理和分子机制

为了探讨减压贮藏延缓采后去壳黄甜竹笋木质化和褐变的效果及其作用机制,本试验以黄甜竹笋为试验材料,笋剥壳后于温度6 ±1℃、相对湿度80%~85%、55 kPa减压环境下贮藏10 d,测定其品质指标、竹笋木质化和褐变关键酶的活性和相关基因的相对表达量。结果表明,减压贮藏(中后期)显著抑制了黄甜竹笋基部切面的褐变(P<0.05),显著延缓了黄甜竹笋的呼吸速率、电导率、硬度,以及丙二醛、纤维素和木质素含量的上升(P<0.05),同时也显著抑制了苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、肉桂醇脱氢酶(CAD)、多酚氧化酶(PPO)的活性及其编码基因的相对表达量(P<0.05)。本研究结果为减压贮藏在黄甜竹笋采后保鲜的应用提供了理论依据。

Effects of Hypobaric Storage on Preservation Quality of Shelled Bamboo Shoots (Acidosasa Edulis) and Its Underlying Physiological and Molecular Mechanisms

In order to study the effects and mechanisms of hypobaric storage condition (55 kPa) on delaying lightfication and browning of postharvest bamboo shoots without sheaths, Acidosasa edulis storage at 6±1℃ along with 80% to 85% relative humidity for 10 days was investigated. Quality parameters, activities of key enzymes and gene expression involved in lignification and browning of bamboo shoots were periodically determined during hypobaric storage. The results indicated that hypobaric storage significantly (P<0.05) inhibited wound browning, slowed down the increase of respiratory rate, flesh firmness, electrical conductivity and accumulation of cellulose, lignin and malondialdehyde (MDA), and significantly (P<0.05) reduced the activities of phenylalanine ammonia lyase (PAL), peroxidase (POD), cinnamyl alcohol dehydrogenase (CAD) and polyphenol oxidase (PPO) and down-regulated the expression of their encoding genes in bamboo shoots during hypobaric storage. The results provided the theoretical foundation of application of hypobaric storage on bamboo shoots storage.