龙眼采后果皮细胞壁代谢相关酶活性的变化

Changes of the Cell-wall Metabolism Enzymes of Pericarp of Longan under Storage

以广东主栽龙眼品种“石硖”和“储良”为试材,研究了在3￣4℃贮藏条件下龙眼果皮中细胞壁代谢相关酶活性的变化。结果表明:储良龙眼果皮比石硖的衰老更快、更严重;储良果皮中的果胶甲酯酶(PME)活性比石硖的高,出现上升的时间早;储良果皮中的多聚半乳糖醛酸酶(PG)、木聚糖酶(Xyl)、β-半乳糖苷酶(β-Gal)活性也高于石硖的,外切半乳糖醛酸酶(exo-PG)活性开始上升的时间也比石硖的早。

The quick browning and frangibility of the pericarp of longan （dimocarpus longan Lour.） are the main factors that influence the storability of longan fruit. Two main cuhivars longan ＂Shixia＇ and ＇Chuliang＇ in Guangdong Province were used as materials to observe the changes of the activities of cell-wall metabolism enzymes of the pericarp of longan stored at 3-4℃. Longan ＇Chuliang＇ showed severer and quicker senescence in pericarp than ＇Shixia＇. The pectinmethylesterase （PME） activity of the pericarp was found higher in ＇Chuliang＇ than in ＇Shixia＇, and it increased earlier in ＇Chuliang＇ than in ＇Shixia＇. The activities of polygalacturonase （PG）, Xylanase （Xyl） and β-Galacturonic acid （β-Gal） of the pericarp were observed higher in ＇Chuliang＇ than in ＇Shixia＇. The activity of exo-polygalacturonase （exo-PG） of the pericarp increased earlier in ＇Chuliang＇ than in ＇Shixia＇ as well. These cell- wall metabolism enzymes may be the important factors resulting in senescence and frangibility of longan fruit periearp.