- 學位論文
介質研磨對枸杞水溶性多醣及其組成之影響
Influence of media milling on water-soluble polysaccharides from Lycium barbarum
摘要
枸杞 (Lycium barbarum L.)為醫食同源的傳統中草藥，具多種藥理作用和生理功能，多醣為主要生理活性物質之一，提供免疫調節、抗腫瘤、延緩老化、降血糖等數種生理活性功效。本實驗室藉由介質研磨 (Media milling)方式成功製備出奈米/次微米枸杞懸浮液，經安全性試驗 (Ames test)，確認奈米/次微米枸杞懸浮液對TA98及TA100菌株不具致突變性。本研究目的為主要鑑定介質研磨對枸杞懸浮液中游離單醣、寡醣與水溶性多醣組成之影響。枸杞經介質研磨90分鐘後，粒數平均粒徑由3.54μm降低為0.101 μm，且小於0.1 μm的粒子數量佔總粒子數的62%，同時以顯微影像觀察證實含有奈米/次微米粒子存在。細碎與研磨枸杞之水溶性粗多醣總醣量，分別為59.98 mg/g dry Lycium與86.47 mg/g dry Lycium；醛醣酸含量分別為30.43 mg/g dry Lycium與45.83 mg/g Lycium。單醣組成上，細碎與研磨組之游離單醣主要均為葡萄糖 (D-Glucose)與果糖 (D-Fructose)；寡醣主要為岩藻糖 (D-Fucose) 與微量的鼠李糖 (D-Rhamnose)、阿拉伯糖 (D-Arabinose)及半乳糖 (D-Galactose)。細碎與研磨組之水溶性粗多醣分子量分布範圍主要均介於6-400 kDa之間。細碎與研磨之水溶性粗多醣主要含有葡萄糖、果糖、鼠李糖、阿拉伯糖、半乳糖、甘露糖 (D-Mannose)、木糖 (D-Xylose) 5種中性單醣，兩組之單醣組成莫耳分率比分別為1 : 3.03 : 1.03 : 0.25 : 0.06與1 : 2.98 : 1.21 : 0.24 : 0.04，在多醣組成比例上差異不大，但個別單醣含量隨著研磨時間增加而增加。利用陰離子交換層析，分離水溶性多醣之中性多醣 (neutral polysaccharide of L. barbarum, LBPN)與酸性多醣 (acidic polysaccharide of L. barbarum, LBPA1與LBPA2)。未去蛋白質前，其LBPN、LBPA1、LBPA2之細碎組總醣比例為14.81 : 51.44 : 33.75與研磨組26.09 : 25.39 : 48.52；去蛋白後細碎組為25.60 : 28.98 : 45.42與研磨組23.20 : 25.57 : 51.23。結果顯示，介質研磨可增加游離單醣、寡醣與枸杞水溶性多醣含量而不影響對游離單醣、寡醣之組成。此外，枸杞水溶性多醣之單醣組成、分子量與酸性多醣比例無明顯差異，即研磨可促使水溶性枸杞多醣釋放，且對其多醣組成與特性無顯著差異。
並列摘要
Lycium barbarum L. has multiple biological and pharmacological activities and has been used as a Chinese medicine and food. Media milling has been successfully employed to prepare nano/submicron Lycium suspension (L. suspension) in our lab, and has no mutagenic effect to the Samonella typhiumurium TA98 and TA100. The objective of this study is to identify free sugar, oligosaccharides and polysaccharides components of media milling Lycium barbarum and to evaluate the effects of media milling on Lycium barbarum polysaccharides (LBP). Media milling for 90min, the number average diameter of L. suspension particle was reduced from 3.54 μm to 0.101 μm, and percentage of particle smaller than 0.1 μm was 62.32%. SEM observation also proved the existence of nano/submicron L. suspension particles. The carbohydrate content of the blended LBP and milled LBP were 59.98 mg/g of dry Lycium and 86.47 mg/g of dry Lycium; and uronic acid content was 30.43 mg/g of dry Lycium and 45.83 mg/g of dry Lycium. For both the blended and milled L. suspension, the monosaccharide composition was D-Glucose and D-Fructose; and the oligosaccharides were consisted of D-Fucose and a few D-Rhamnose, D-Arabinose and D-Galactose. The molecular weight of the blended and milled LBP had a widely distributed rang of 6 - 2000 kDa. Polysaccharides extracted from the blended and milled L. suspension consist of D-Galactose, D-Glucose, D-Arabinose, D-Xylose and D-Mannose in a molar ratio of 3.03 : 1.03 : 1 : 0.25 : 0.06, and 2.98 : 1.21 : 1 : 0.24 : 0.04, respectively. Blended and milled water-soluble polysaccharide can be separated into neutral polysaccharide of L. barbarum (LBPN) and acidic polysaccharide of L. barbarum (LBPA1 and LBPA2) fractions by DEAE. For the total carbohydrate content, the LBPN, LBPA1 and LBPA2 was 14.81 : 51.44 : 33.75 for blended LBP; and 14.16 : 55.71 : 29.68 for milled LBP, before deproteination. After deproteination, LBPN, LBPA1 and LBPA2 was 46.18 : 29.57 : 24.24 for blended; and 39.14 : 30.40 : 30.46 for milleded LBP. Media milling can increase free sugar, oligosaccharide and LPB content, but does affect the composition of free sugar and oligosaccharide. There is no significant difference in sugar composition, molecular weight and content of acidic polysaccharides of LBP. The result showed that water-soluble polysaccharides from L. barbarum can be released by media milling but the process dose not significantly affect their property and sugar composition.