Abstract

Effects of the combination of extrusion pretreatment and enzymatic hydrolysis on corn starch are investigated through its microstructural and physicochemical properties. This combined modification resulted in the formation of more pores on the surface of native starches (NS), as revealed by scanning electron microscopy (SEM). Compared with either single-treatment modified starch samples, starch that was bioextruded and treated by enzymatic hydrolysis achieved higher crystallinity, more uniform pore structure, and higher gelatinization temperature than those of native porous starch, as determined by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), and differential scanning calorimetry (DSC). Low-temperature nitrogen adsorption experiments showed that the specific surface area (2.52 m²/g), total pore volume (4.53 × 10⁻³ cm³/g), and average pore size (7.36 nm) of porous starch were significantly increased by bioextrusion combined with enzyme hydrolysis (P < 0.05). The results of hydrolysis degree (DH) also showed that bioextrusion could improve the efficiency of hydrolysis. Starch that was bioextruded followed by enzyme hydrolysis showed the highest adsorption capacity in adsorption tests of adsorption of oil (63.29%), water (162.61%), and methylene blue (6.04%). The present study suggests that the combination of bioextrusion pretreatment and enzymatic hydrolysis is an attractive alternative for preparing porous corn starches.

中文翻译：

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挤压技术与酶水解结合对玉米淀粉多孔结构和理化性质的影响

摘要

通过挤压淀粉的微结构和理化性质研究了挤压预处理和酶水解相结合对玉米淀粉的影响。如通过扫描电子显微镜（SEM）所揭示的，这种组合的修饰导致在天然淀粉（NS）的表面上形成更多的孔。通过X射线衍射（XRD）测定，与单处理改性淀粉样品相比，经生物挤压和酶水解处理的淀粉比天然多孔淀粉具有更高的结晶度，更均匀的孔结构和更高的糊化温度，傅立叶变换红外（FTIR）和差示扫描量热法（DSC）。低温氮吸附实验表明，比表面积（2.52 m ²/ g），生物挤压结合酶水解显着增加了多孔淀粉的总孔体积（4.53×10 ^-3  cm ³ / g）和平均孔径（7.36 nm）（P  <0.05）。水解度（DH）的结果还表明，生物挤出可以提高水解效率。在油（63.29％），水（162.61％）和亚甲基蓝（6.04％）的吸附测试中，经生物挤压后酶水解的淀粉显示出最高的吸附能力。本研究表明，生物挤压预处理和酶水解的组合是制备多孔玉米淀粉的有吸引力的替代方法。