Marquez-Escalante Jorge A, Carvajal-Millan Elizabeth, Yadav Madhav P, Kale Madhuvanti, Rascon-Chu Agustín, Gardea Alfonso A, Valenzuela-Soto Elisa M, Lopez-Franco Yolanda L, Lizardi-Mendoza Jaime, Faulds Craig B
Centro de Investigación en Alimentación y Desarrollo (CIAD, AC), Hermosillo, Sonora, Mexico.
Eastern Regional Research Center, Agricultural Research Service, US Department of Agriculture, Wyndmoor, PA, USA.
J Sci Food Agric. 2018 Feb;98(3):914-922. doi: 10.1002/jsfa.8537. Epub 2017 Aug 28.
Arabinoxylans (AX) are polysaccharides consisting of a backbone of xyloses with arabinose substituents ester-linked to ferulic acid (FA). The arabinose to xylose ratio (A/X) in AX may vary from 0.3 to 1.1. AX form covalent gels by cross-linking of FA but physical interactions between AX chains also contribute to the network formation. The present study aimed to investigate the rheological and microstructural characteristics of gels based on AX enzymatically modified in A/X.
Tailored AX presented A/X ranging from 0.68 to 0.51 and formed covalent gels. Dimers of FA content and elasticity (G') increased from 0.31 to 0.39 g kg AX and from 106 to 164 Pa when the A/X in the polysaccharide decreased from 0.68 to 0.51. Atomic force microscopy images of AX gels showed a sponge-like microstructure at A/X = 0.68, whereas, at lower values, gels presented a more compact microstructure. Scanning electron microscopy analysis of AX gels show an arrangement of different morphology, passing from an imperfect honeycomb (A/X = 0.68) to a flake-like microstructure (A/X = 0.51).
Lower A/X values favor the aggregation of AX chains resulting in an increase in di-FA content, which improves the rheological and microstructural characteristics of the gel formed. © 2017 Society of Chemical Industry.
阿拉伯木聚糖（AX）是一种多糖，其木糖主链上带有与阿魏酸（FA）酯键相连的阿拉伯糖取代基。AX中阿拉伯糖与木糖的比例（A/X）可能在0.3至1.1之间变化。AX通过FA的交联形成共价凝胶，但AX链之间的物理相互作用也有助于网络形成。本研究旨在研究基于A/X经酶促修饰的AX凝胶的流变学和微观结构特征。
定制的AX的A/X范围为0.68至0.51，并形成了共价凝胶。当多糖中的A/X从0.68降至0.51时，FA二聚体含量和弹性（G'）从0.31 g/kg AX增加到0.39 g/kg AX，从106 Pa增加到164 Pa。AX凝胶的原子力显微镜图像显示，在A/X = 0.68时为海绵状微观结构，而在较低值时，凝胶呈现出更致密的微观结构。AX凝胶的扫描电子显微镜分析显示出不同形态的排列，从不完美的蜂窝状（A/X = 0.68）转变为片状微观结构（A/X = 0.51）。
较低的A/X值有利于AX链的聚集，导致二-FA含量增加，从而改善了所形成凝胶的流变学和微观结构特征。© 2017化学工业协会。
