挤压与低温贮藏对玉米淀粉-月桂酸复合物理化及消化性质的影响

Effect of Cool Storage on the Physicochemical Properties and Digestibility of Extruded Common Corn Starch-Lauric Acid Complex

采用挤压处理结合低温贮藏制备普通玉米淀粉-月桂酸复合物(common corn starch-lauric acid complex,CSLA),通过差示扫描量热仪(differential scanning calorimetry,DSC)、X射线衍射仪等方法系统探究了挤压处理结合低温贮藏对CSLA糊化度、复合指数、热性质、结晶结构及消化性质的影响规律。结果表明,与挤压处理相比,挤压处理结合低温贮藏有利于形成普通玉米淀粉-月桂酸复合物,复合指数由29%增加至35%,相对结晶度由25.20%增加至31.82%;挤压处理结合低温贮藏能降低复合物的消化能力,使复合物抗性淀粉(resistant starch,RS)含量由38.07%升高至49.82%。热性质的结果表明:挤压处理结合低温贮藏使普通玉米淀粉与月桂酸形成了热稳定性稍差的VI-型复合物,熔融温度为89.95~101.33℃,而普通玉米淀粉与内源性脂质形成了热稳定性较高的VII-型复合物,熔融温度为106.73~117.48℃。研究结果可为具有较低消化能力的淀粉-脂肪酸复合物和抗消化淀粉食品的制备提供参考。

Common corn starch-lauric acid complex(CSLA)was prepared by extrusion treatment combined with cool storage.The effects of extrusion treatment combined with cool storage on the gelatinization degree,complexing index,thermal properties,crystal structure and digestive properties of CSLA were systematically investigated by means of differential scanning calorimetric analysis(DSC)and X-ray diffraction analysis(XRD).The results showed that compared with extrusion treatment,extrusion treatment combined with cool storage was beneficial to the formation of common corn starch-lauric acid complex,the complexing index increased from 29%to 35%,and the relative crystallinity increased from 25.20%to 31.82%.Extrusion treatment combined with cool storage can reduce the digestibility of the compound and increase the content of RS from 38.07%to 49.82%.The results of thermal properties showed that extrusion treatment combined with cool storage made common corn starch and lauric acid form VI-type complex with low thermal stability,and the melting temperature was 89.95~101.33℃,while common corn starch and endogenous lipids formed a VII-type complex with high thermal stability,and the melting temperature was 106.73~117.48℃.The results can provide reference for the preparation of starch-fatty acid complex with low digestibility and the preparation of anti-digestibility starch food.