可食性褐藻纤维素的分离纯化与结构分析

Isolation,Purification and Structural Analysis of Cellulose from Edible Brown Seaweeds

以我国主要可食性褐藻海带和裙带菜为对象,对其中的纤维素成分进行分离纯化,并分析纤维素的结构属性。海带的纤维素含量明显高于裙带菜,二者纤维素的提取率分别达原料干质量的5.59%及2.61%。通过酸水解-高效液相色谱分析及傅里叶变换红外光谱分析,提取的纤维素的纯度分别达99.86%及98.91%。海带纤维素的平均聚合度为813,高于裙带菜纤维素的315。粉末X射线衍射分析揭示了2种褐藻纤维素均具有天然高度结晶性结构,结晶度指数分别达72.06%和71.48%,与市售高等植物来源微晶纤维素的水平相当。对X射线衍射图谱的进一步解析表明:褐藻纤维素的结晶性区域以单链三斜晶系(Iα)为主,显著区别于高等植物纤维素的双链单斜晶系(Iβ)为主的结构。研究结果以期为优质膳食纤维资源的开发提供参考。

Cellulose was extracted from kelp and wakame,which were two major edible brown seaweeds in China,and the structural features were analyzed and compared.The kelp had significantly higher cellulose content than that of the wakame,and the cellulose extraction yields were 5.59%and 2.61%of the dry seaweeds.The purity of the cellulose samples reached 99.86%and 98.91%according to the acid hydrolysis-HPLC analysis and FT-IR analysis.The kelp cellulose had a degree of polymerization of 813,which was significantly higher than that of the wakame of 315.X-ray powder diffraction analysis revealed that two kinds of brown seaweed cellulose both had natively highly crystalline structure,with the crystallinity indexes reaching 72.06%and 71.48%,which were comparable to that of the commercial microcrystalline cellulose derived from advanced plant.Further analysis of the X-ray diffractograms suggested that the crystalline region of the brown seaweed cellulose featured Iα(one-chain triclinic)phase-rich structure,evidently different from Iβ(two-chain monoclinic)phase-rich structure of cellulose from advanced plant.This study provides a reference for resource development of high quality dietary fiber.