Sasaki Tomoko, Noel Timothy R, Ring Steve G
National Food Research Institute, Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
J Agric Food Chem. 2008 Feb 13;56(3):1091-6. doi: 10.1021/jf072424j. Epub 2008 Jan 9.
Potato amylopectin with phosphate groups was immobilized on a quartz crystal microbalance with dissipation monitoring (QCMD) using the attractive interaction between opposite charges, and enzymatic starch hydrolysis was monitored directly. Poly( L-lysine) (PLL) proved to be an appropriate cationic linker between the QCMD silica sensor and potato amylopectin. Increased mass and dissipation were observed when amylopectin was adsorbed onto the PLL layer and reversed when alpha-amylase was added. The effect of chitosan with cationic property on the hydrolysis of amylopectin was studied. Chitosan was observed to be adsorbed onto the amylopectin surface and to suppress hydrolysis by alpha-amylase. The formation of alternating layers of amylopectin and chitosan was monitored by QCMD. Amylopectin-chitosan trilayers increased resistance to digestion by alpha-amylase compared to one layer and to control without chitosan.
利用相反电荷之间的吸引相互作用，将带有磷酸基团的马铃薯支链淀粉固定在具有耗散监测功能的石英晶体微天平（QCMD）上，并直接监测酶促淀粉水解过程。聚（L-赖氨酸）（PLL）被证明是QCMD二氧化硅传感器与马铃薯支链淀粉之间合适的阳离子连接体。当支链淀粉吸附到PLL层上时，观察到质量增加和耗散增加，而添加α-淀粉酶后则相反。研究了具有阳离子性质的壳聚糖对支链淀粉水解的影响。观察到壳聚糖吸附在支链淀粉表面，并抑制α-淀粉酶的水解作用。通过QCMD监测支链淀粉和壳聚糖交替层的形成。与单层支链淀粉以及不含壳聚糖的对照相比，支链淀粉-壳聚糖三层结构对α-淀粉酶消化的抗性增强。
