热处理对萌芽藜麦粉特性及血糖生成指数的影响

Effects of Heat Treatment on Physicochemical Properties and Estimate Glycemic Index of Germinated Quinoa Flour

为改善萌芽藜麦生粉的特性,探讨不同热处理方式(炒制、挤压膨化、热风)对萌芽藜麦粉的色度、溶解性、糊化特性、糊化度、动态流变及其体外血糖生成指数的影响。结果表明,热处理萌芽藜麦粉的亮度值较萌芽藜麦生粉显著降低(P<0.05),炒制粉、挤压膨化粉和热风处理粉的色差值分别为4.1、17.0和8.0;热处理粉的水溶性指数、峰值黏度、回生值较萌芽藜麦生粉显著提高(P<0.05),而衰减值、吸水性指数则显著降低;3种热处理粉中,挤压膨化粉的水溶性指数、黏度值、衰减值和回生值显著低于炒制粉和热风处理粉,但其糊化度最高,达到84.0%;萌芽藜麦生粉及热处理粉均表现为弱凝胶特性。挤压膨化萌芽藜麦粉的体外血糖生成指数(50.78)显著低于生粉(52.11)、热风处理粉(52.21)、炒制粉(52.92)。挤压膨化处理可有效提高萌芽藜麦粉的糊化度,降低产品的黏度和血糖指数,是开发具有良好加工特性与消化特性萌芽藜麦粉的适宜热处理方法。

To improve the properties of germinated quinoa flour,the effects of three different heat treatment methods(roasting,extrusion puffing,and hot⁃air exposure)on physicochemical properties of germinated qui⁃noa such as chroma,solubility,gelatinization properties and degree,dynamic rheology and in vitro glycemic in⁃dex was explored in this study.The results showed that the three kinds of quinoa flour with different heat treat⁃ments had significantly low brightness compared with the raw flour(P<0.05),and the color difference(ΔE)values of germinated quinoa flours treated by roasting,extrusion puffing and hot⁃air exposure were 4.1,17.0 and 8.0,respectively.The water solubility index,peak viscosity,and recovery value of flour by heat treatment were significantly increased(P<0.05),while the attenuation value and water absorption index were signifi⁃cantly decreased.Among the three heat treatment flour,the water solubility index,viscosity value,attenuation value,and retrogradation value of extrusion puffing flour were significantly lower than those of roasting flour and hot⁃air exposure flour.However,the gelatinization degree for extrusion puffing flour was 84.0%,which was the highest among all treated quinoa flour.All the raw and heat⁃treated flour showed weak gel characteristics.The estimated glycemic index of extrusion puffing flour(50.78)was significantly lower than that of raw flour(52.11),hot air explosion flour(52.21),and roasting flour(52.92).Extrusion puffing can effectively improve the gelatinization degree of germinated quinoa flour and reduce the viscosity and glycemic index of the product,which is the preferred heat treatment method for developing germinated quinoa flour with good processing and digestion properties.