双螺杆挤压对玉米重组米理化特性及品质特性的影响

Effect of Twin-Screw Extrusion on Physicochemical Properties and Quality Characteristics of Corn Flour

为研究双螺杆挤压技术对玉米粉挤压前后理化特性及品质特性的影响,采用SLG-30双螺杆挤压机对吉林省17个品种玉米进行挤压膨化,对双螺杆挤压处理前后重组米理化特性及品质特性进行分析。结果表明,挤压处理后不同品种玉米粉的蛋白质量分数平均降低11.32%,脂肪质量分数平均降低29.88%,直链淀粉质量分数平均降低5.11%,冻融稳定性平均提高58.90%,糊化度平均提高88.62%,吸水性平均提高77.03%,水溶性平均提高73.57%,膨润力平均提高87.51%。相关性分析表明,挤压处理后糊化度与脂肪、直链淀粉、蛋白质量分数均呈负相关,与吸水性和水溶性均呈极显著正相关(P<0.01);直链淀粉、脂肪质量分数与冻融稳定性、糊化度、吸水性和水溶性均呈极显著负相关(P<0.01)。挤压处理对玉米的理化特性指标有负面影响,但能明显提高产品加工性能和食用特性。

In order to study the effect of twin-screw extrusion on the physicochemical properties and quality characteristics of corn flour,a model SLG-30 twin-screw extruder was used to extrude 17 varieties of corn in Jilin province.Changes in the physicochemical properties and quality characteristics were analyzed before and after extrusion.The results showed that all varieties exhibited a decrease in protein content by 11.32%,in fat content by 29.88%,and in amylose content by 5.11%on average,as well as an increase in freeze-thaw stability by 58.90%,in gelatinization degree by 88.62%,in water-absorbing capacity by 77.03%,in water solubility by 73.57%,and in swelling power by 87.51%on average after extrusion.Correlation analysis showed that the degree of gelatinization was negatively correlated with fat,amylose and protein contents in extruded corn,but was extremely signi ficantly positively correlated with water-absorbing capacity and water solubility(P<0.01);amylose and fat contents were both extremely signi ficantly negatively correlated with freeze-thaw stability,gelatinization degree,water-absorbing capacity and water solubility(P<0.01).Therefore,extrusion treatment has a negative impact on the physicochemical properties of corn flour,but it can signi ficantly improve the processing properties and eating characteristics of the product.