Structure and rheological characteristics of fucoidan from sea cucumber Apostichopus japonicus

卷:180

Yu, Long ; Xue, Changhu ; Chang, Yaoguang ; Hu, Yanfang ; Xu, Xiaoqi ; Ge, Lei ; Liu, Guanchen

关键词: Fucoidan;    Sea cucumber;    Apostichopus japonicus;    Structure;    Viscosity;    Rheological behaviour;   

DOI  :  10.1016/j.foodchem.2015.02.034

学科分类：食品科学和技术

【 摘 要 】

Sea cucumber is a traditional health food consumed in East Asia. In this study, fucoidan from sea cucumber Apostichopus japonicus (Aj-FUC) was isolated, and its structure and rheological characteristics were elucidated for the first time. Aj-FUC was a branched polysaccharide mainly composed of a novel repeating unit [alpha-L-Fucp2(OSO3-)-1 -> 3,(alpha-L-Fucp-1 -> 4-alpha-L-Fucp-1 ->)4-alpha-L-Fucp2(OSO3-)-1 -> 3-alpha-L-Fucp2(OSO3-)], clarified by using a combination of infrared spectroscopy, methylation analysis, enzymatic degradation and nuclear magnetic resonance. In steady shear measurement, Aj-FUC manifested a non-Newtonian shear-thinning behaviour at low shear rate (1-100 S-1) while exhibiting a non-Newtonian shear-thickening behaviour at high shear rate (100-1000 S-1); salts had limited impact on its flow curve. Comparative study on viscosity and rheological behaviour of Aj-FUC and a linear fucoidan extracted from sea cucumber Acaudina molpadioides suggested that the presence of branch structure might significantly influence the rheological characteristics of fucoidan. (C) 2015 Elsevier Ltd. All rights reserved.