Xu Xiaoqi, Xue Changhu, Chang Yaoguang, Liu Guanchen
College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
Food Chem. 2017 Dec 15;237:511-515. doi: 10.1016/j.foodchem.2017.05.103. Epub 2017 May 19.
As a bioactive and functional polysaccharide, sea cucumber fucoidan has received increasing attention. Chain conformation and physicochemical properties of fucoidan extracted from Thelenota ananas (Ta-FUC) was investigated by utilizing HPSEC-MALLS-Visc-RI, microelectrophoresis and steady shear measurements. The conformation parameter α (0.61±0.02), the Mark-Houwink-Kuhn-Sakurada exponent α (0.92±0.01), α (0.64±0.01) and the Smidsrød-Haug stiffness parameter B (0.036±0.010) consistently manifested that Ta-FUC adopted a semi-flexible coil conformation in NaCl solution. Based on a wormlike cylinder model, stiffness parameters, including persistence length q (13.27±0.80nm) and cylinder diameter d (0.79nm), were calculated. This polysaccharide demonstrated shear-thinning rheological behaviour, and critical concentration from dilute to semidilute concentration regime was determined as 3.6mg/ml. Ta-FUC exhibited as a negative polyelectrolyte in wide pH and ionic strength ranges. These molecular characteristics and physicochemical properties would facilitate further application of Ta-FUC as a functional ingredient in food.
作为一种生物活性和功能性多糖，海参岩藻聚糖受到了越来越多的关注。利用高效体积排阻色谱-多角度激光光散射-粘度-示差折光联用仪（HPSEC-MALLS-Visc-RI）、微电泳和稳态剪切测量对从梅花参中提取的岩藻聚糖（Ta-FUC）的链构象和物理化学性质进行了研究。构象参数α（0.61±0.02）、马克-豪温克-库恩-樱田指数α（0.92±0.01）、α（0.64±0.01）以及斯米德罗德-豪格刚度参数B（0.036±0.010）一致表明Ta-FUC在NaCl溶液中呈半柔性卷曲构象。基于蠕虫状圆柱体模型，计算了包括持久长度q（13.27±0.80nm）和圆柱体直径d（0.79nm）在内的刚度参数。这种多糖表现出剪切变稀的流变行为，从稀溶液到半稀溶液浓度范围的临界浓度确定为3.6mg/ml。Ta-FUC在较宽的pH值和离子强度范围内表现为负聚电解质。这些分子特征和物理化学性质将有助于Ta-FUC作为功能性成分在食品中的进一步应用。
