Ma Mengting, Xu Zekun, Wu Huaixiang, Li Kewen, Sun Guilian, He Jinxing, Sui Zhongquan, Corke Harold
College of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China; Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
Int J Biol Macromol. 2022 Oct 31;219:473-481. doi: 10.1016/j.ijbiomac.2022.07.219. Epub 2022 Jul 30.
Starch granule-associated surface and channel lipids (SGALs) were effectively removed from waxy maize starch (WMS) and normal maize starch (NMS), then the starches were crosslinked by different levels of sodium trimetaphosphate (STMP) (0.25 %, 0.5 %, 1 % and 2 %). The effective removal of SGALs and successful crosslinking, were evidenced by the disappearance of surface-fluorescence and channel-fluorescence of Pro-Q Diamond-stained granules, and the increased phosphorus content respectively. STMP crosslinking increased peak and final viscosity for WMS and NMS. Crosslinking at high STMP levels (0.5 %, 1 % and 2 %) transformed the starch pastes from thixotropic to anti-thixotropic. STMP crosslinking significantly decreased the tan δ values of maize starches, enhancing the elastic structure of the gel. Crosslinked maize starches without SGALs had lower breakdown than crosslinked starches at same STMP level, indicating higher tightened crosslinked starch granules after SGALs removal. Removal of SGALs increased the anti-thixotropy of crosslinked starches, facilitating the reorientation of crosslinked amylopectin/amylose molecules during shearing. Removal of SGALs increased the tan δ values from frequency sweep of WMS and NMS during STMP crosslinking, indicating the presence of surface-lipids and channel-lipids could enhance the elastic gel network structure of crosslinked maize starch.
蜡质玉米淀粉（WMS）和普通玉米淀粉（NMS）中的淀粉颗粒相关表面和通道脂质（SGALs）被有效去除，然后用不同水平的偏磷酸钠（STMP）（0.25%、0.5%、1%和2%）对淀粉进行交联。Pro-Q Diamond染色颗粒的表面荧光和通道荧光消失，以及磷含量增加，分别证明了SGALs的有效去除和成功交联。STMP交联提高了WMS和NMS的峰值粘度和最终粘度。高STMP水平（0.5%、1%和2%）的交联使淀粉糊从触变性转变为抗触变性。STMP交联显著降低了玉米淀粉的损耗角正切值，增强了凝胶的弹性结构。在相同STMP水平下，去除SGALs的交联玉米淀粉的破损值低于交联淀粉，表明去除SGALs后交联淀粉颗粒更加紧密。去除SGALs增加了交联淀粉的抗触变性，有利于交联支链淀粉/直链淀粉分子在剪切过程中的重新定向。去除SGALs增加了STMP交联过程中WMS和NMS频率扫描的损耗角正切值，表明表面脂质和通道脂质的存在可以增强交联玉米淀粉的弹性凝胶网络结构。
