采收期对香菇耐贮特性及抗氧化酶系统的影响

以两种商业采收期(未开伞成熟度与开伞成熟度)的香菇(Lentinus edodes)为实验材料，研究其在15℃贮藏过程中开伞度、质量损失率、呼吸强度、水分含量、抗坏血酸含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的变化。整个贮藏中，开伞成熟度香菇伞盖直径变化率、呼吸速率分别是未开伞成熟度香菇的1.5～2.5、1.2～1.8 倍；贮藏至第7 天时，水分含量仅为未开伞成熟度香菇的0.5 倍，抗坏血酸含量下降量比未开伞成熟度香菇高出21.8%；并且贮藏期间，未开伞成熟度香菇的SOD、POD 及CAT 活性始终高于开伞成熟度香菇(P ＜ 0.05)。结果表明，与开伞成成熟度香菇相比，未开伞成熟度香菇具有较好的耐贮性品质及较高的抗氧化能力。

Effect of Harvest Time on Storage Quality and Antioxidant Enzyme Activities of Lentinus edodes

Two groups of shiitake mushroom (Lentinus edodes) with different harvest times (early commercial maturity stage when cap is closed and later stage when cap is open) were stored at 15 ℃, and dynamic changes in cap opening, weight loss rate, respiratory intensity, moisture content, ascorbic acid content and the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were determined. Throughout the storage, the pileus diameter and respiratory intensity of shiitake mushroom with closed cap were 1.5 － 2.5 and 1.2 － 1.8 times higher than those of shiitake mushroom with open cap, respectively. At the end of the storage, moisture content of late-harvested shiitake mushroom was only half of that of earlyharvested shiitake mushroom, and the decline of ascorbic acid content was 21.8% higher than that of early-harvested shiitake mushroom. Furthermore, the activities of SOD, POD and CAT in early-harvested shiitake mushroom were always maintained at higher levels during the storage (P ＜ 0.05). The results show that early-harvested shiitake mushroom has better storage qualities and higher antioxidant ability in comparison with late-harvested shiitake mushroom.