Comprehensive investigation and comparison of surface microstructure of fractionated potato starches
Comprehensive investigation and comparison of surface microstructure of fractionated potato starches
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马铃薯分级淀粉表面微观结构的综合研究与比较
DOI：
10.1016/j.foodhyd.2018.10.017
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发表时间：
2019-04-01
影响因子：
10.7
通讯作者：
Jin, Zhengyu
中科院分区：
文献类型：
--
作者：
Chen, Long;Ma, Rongrong;Jin, Zhengyu
将马铃薯淀粉（PS）颗粒按体积加权平均粒径分为极小（VS）、极小(S)、中粒(M)和大粒(L)四组。采用激光粒度分析、激光共聚焦扫描显微镜（CLSM）和扫描电镜（SEM）对淀粉组分的粒度分布和形貌进行了研究。淀粉颗粒在PS-VS和PS-S组分中呈球形，在PS-M组分中呈椭球状，在PS-L组分中呈细长状。采用原子力显微镜（AFM）和低温氮吸附技术对马铃薯淀粉颗粒的纳米级表面特征进行了进一步研究。AFM图像显示，不同分级颗粒表面具有不同的纳米级“小块”结构，表明支链淀粉侧链在表面的分子自组装存在差异。图像分析表明，PS-VS和PS-S组分比PS-M和PS-L组分具有更均匀的表面。氮吸附分析表明，PS-VS和PS-S组分的孔径范围较窄，说明粒径较小的颗粒形貌更为均匀。相反，PS-M和PS-L组分孔径范围宽，表面结构不均匀。淀粉颗粒的表面结构和纳米级结构与淀粉的糊化性能密切相关，为研究淀粉颗粒的结构-功能关系提供了新的视角。
Potato starch (PS) granules were separated into four fractions based on their volume-weighted mean diameters: very small (VS), small (S), medium (M) and large (L) granules. The particle size distribution and morphology of the starch fractions were investigated by laser particle size analysis, confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM). The starch granules were spherical in the PS-VS and PS-S fractions, ellipsoid in the PS-M fraction, and elongated in the PS-L fraction. The nanoscale surface features of fractionated potato starch granules were further investigated using atomic force microscopy (AFM) and low-temperature nitrogen adsorption. AFM images showed that different fractionated granules had different nanoscale `blocklet' structures on their surfaces, indicating differences in the molecular self-assembly of amylopectin side chains at the surfaces. Image analysis showed that PS-VS and PS-S fractions had more homogeneous surfaces than PS-M and PS-L fractions. Nitrogen adsorption analysis showed that the PS-VS and PS-S fractions had a narrow range of pore diameters, indicating a more homogeneous morphology of the smaller granules. Conversely, PS-M and PS-L fractions had broad range of pore diameters and a heterogeneous surface structure. The surface texture and nanoscale structures of the starch granules were significantly correlated to the pasting properties of starch, providing a new perspective on the structure-function relationship of starch granules.