响应面试验优化挤出酶解复合法改性玉米淀粉工艺

利用挤出酶解对玉米淀粉进行改性，采用响应面法对影响改性工艺的主要因素耐高温α-淀粉酶添加量、挤出温度、玉米淀粉含量进行优化，通过高效液相色谱、扫描电子显微镜、X-射线衍射以及差示扫描量热仪对玉米淀粉挤出酶解复合改性前后的低聚糖组成、表观结构、结晶度以及热力学性质的变化进行分析。结果表明：当耐高温α-淀粉酶添加量40 U/g、挤出温度140 ℃、玉米淀粉含量70%时，挤出改性玉米淀粉葡萄糖当量值为19.55%。高效液相色谱分析表明挤出物低聚糖的组分能够得到较好的分离，低聚糖样品中各组分葡萄糖、麦芽糖、麦芽三糖、麦芽四糖、麦芽五糖的质量比为1.0∶3.4∶7.5∶6.0∶1.8。玉米淀粉经挤出酶解复合改性后颗粒表面出现孔洞，结晶度下降。

Optimization of Modification Process for Corn Starch Using Enzymatic Hydrolysis Combined with Extrusion by Response Surface Methodology

Response surface methodology (RSM) was used to optimize the modification process for corn starch by enzymatic
hydrolysis combined with extrusion. Main process parameters including high temperature resistant α-amylase dosage,
extrusion temperature and corn starch concentration were studied. The sugar composition, microstructure, crystallinity
and thermodynamic properties of corn starch before and after modification was examined by high performance liquid
chromatography (HPLC), scanning electron microscope, X-ray diffraction technique and differential scanning calorimetry. The
results showed that when 40 U/g of high temperature-resistant α-amylase was added, the extrusion was performed at 140 ℃
and corn starch concentration was 70%, the maximum DE value of 19.55% was achieved. HPLC analysis showed that the
sugar components of the extruded product were separated effectively with a ratio of glucose to maltose to maltotriose to
maltotetraose to maltopentaose of 1.0:3.4:7.5:6.0:1.8. The microstructure of the modified starch particles exhibited holes on
the surface and the degree of crystallinity decreased.