油橄榄叶多糖的提取工艺优化及其理化性质和抗氧化活性

为增加油橄榄叶多糖的开发利用价值，以油橄榄叶为实验材料，采用正交试验优化油橄榄叶多糖(OLP)的提取工艺，高效凝胶渗透色谱-多角度激光光散射仪联用(HPGPC-MALLS)测定分子量，PMP柱前衍生高效液相色谱法分析OLP的单糖组成，并评价其抗氧化活性。结果显示，OLP的最佳提取工艺条件为料液比1:27.5g/mL，温度95℃，提取时间3.5 h，在此条件下OLP的得率为2.75%;OLP的重均分子量(Mw)为25.36 kDa，数均分子量(Mn)为19.32 kDa，多分散系数为1.313;OLP主要由葡萄糖(Glc)、半乳糖(Gal)和氨基半乳糖(GalN)组成，还含有鼠李糖(Rha)、阿拉伯糖(Ara)、木糖(Xyl)、甘露糖(Man)和氨基葡萄糖(GlcN)等单糖，各单糖的相对摩尔比为56.2:15.9:10.3:8.3:5.9:2.6:0.5:0.3；抗氧化活性实验结果发现，OLP具有较好的抗氧化活性，对羟自由基、超氧阴离子自由基和DPPH自由基的半数抑制浓度(IC₅₀)分别为0.422、0.302和0.268 mg/mL。本研究所得油橄榄叶多糖的提取工...

Optimization of Extraction Process of Polysaccharides from Olea europaea L. Leaves and Its Physicochemical Properties and Antioxidant Activity

In order to increase the development and utilization value of polysaccharides from Olea europaea L. leaves, the extraction process of polysaccharides from Olea europaea L. leaves (OLP) was optimized by orthogonal experiment, the molecular weight was determined by high performance gel permeation chromatography combined with multi-angle laser light scattering (HPGPC-MALLS), and the monosaccharide composition of OLP was analyzed by PMP pre-column derivatization and its antioxidant activity was evaluated. The results showed that the optimal extraction conditions were material-liquid ratio of 1:27.5 g/mL, extraction temperature of 95 ℃ and extraction time of 3.5 h. Under these conditions, the yield of OLP was 2.75%. The average weight molecular weight (Mw) of OLP was 25.36 kDa, the average number molecular weight (Mn) was 19.32 kDa, and the polydispersity was 1.313. OLP was mainly composed of glucose (Glc), galactose (Gal) and galactose amino (GalN), but also contains rhamnose (Rha), arabinose (Ara), xylose (Xyl), mannose (Man) and glucosamine (GlcN), and the relative molar ratio of monosaccharide was 56.2:15.9:10.3:8.3:5.9:2.6:0.5:0.3. The results showed that OLP had good antioxidant activity, with IC₅₀ of 0.422, 0.302 and 0.268 mg/mL for hydroxyl free radical, superoxide anion free radical and DPPH free radical, respectively. The optimum technology of OLP is simple, the yield is high, and the antioxidant activity is good, which provides an essential reference for the further research, development and utilization of OLP.