Molecular Structure and Physicochemical Properties of Starches from Rice with Different Amylose Contents Resulting from Modification of OsGBSSI Activity

• DOI: 10.1021/acs.jafc.6b05448
• Publication Date: 2017-02-27T23:23:51Z
• Authors: Changquan Zhang; Shengjie Chen; Xinyu Ren; Yan Lu; Derui Liu; Xiuling Cai; Qianfeng Li; Jiping Gao; Qiaoquan Liu
• Keywords: Gel permeation chromatography; Degree of polymerization

OsGBSSI, encoded by the Waxy (Wx) gene, is key enzyme in synthesis of amylose chains. Transgenic rice lines with various GBSSI activities were previously developed via site-directed mutagenesis Wx gene glutinous cultivar Guanglingxiangnuo (GLXN). In this study, grain morphology, molecular structure, and physicochemical properties investigated four transgenic modified OsGBSSI activity differences content. A milky opaque appearance was observed low- non-amylose grains due to air spaces starch granules. Gel permeation chromatography (GPC) high-performance anion-exchange (HPAEC) analyses showed that although can synthesize intermediate extra-long amylopectin chains, it mainly responsible for longer Amylose content positively correlated trough viscosity, final setback pasting time, temperature, gelatinization temperature negatively gel consistency, breakdown enthalpy, crystallinity. Overall, findings suggest may be also involved biosynthesis, turn affecting appearance, thermal properties, crystalline structure starches endosperm.