不同添加量的氨基酸辅助干热处理对玉米淀粉理化和消化性质的影响

Effect of Different Amounts Amino Acid Combined with Dry-heat Treatment on Physicochemical and Digestive Properties of Common Corn Starch

以玉米淀粉为原料,通过氨基酸(天冬氨酸和赖氨酸)辅助干热处理对其改性,采用快速黏度仪、差式扫描量热仪、X射线衍射仪,对不同氨基酸添加量(0.5%、2%、4%和10%,w/w)的干热玉米淀粉的糊化特性、热特性、结构特性和消化性质进行了研究。结果表明,氨基酸添加量对干热处理玉米淀粉-氨基酸混合物的理化性质和消化性质有显著影响。随着两种氨基酸添加量的增多,淀粉的峰值黏度、回生值和糊化焓值降低,而相对结晶度和抗性淀粉含量升高;干热玉米淀粉-天冬氨酸混合物的糊化温度呈先升高而后降低的趋势,干热玉米淀粉-赖氨酸混合物的糊化温度呈升高趋势。提高氨基酸添加量能促进淀粉颗粒内部的晶体排列更紧密、有序,能更好地抑制淀粉的短期老化,降低淀粉的消化性能;可作为玉米淀粉改性的一种新方法,为生产改性淀粉提供参考。

Corn starch was modified by dry heat treatment combined with amino acids(aspartic acid and lysine)in the present research.Gelatinization,thermal,structural,and digestive properties of dry heat-treated corn starch with different amount of amino acids were investigated by using Rapid Viscosity Analyser,differential scanning calorimetry,and X-ray diffractometry.The results indicated that the amount of amino acids showed significant effects on the physicochemical properties and digestive properties of dry heat-treated corn starch-amino acid mixtures.With increasing the addition of amino acids,peak viscosity,setback value,and gelatinization enthalpy of starch decreased,while relative crystallinity and resistant starch content increased.Gelatinization temperature of dry heat-treated corn starch-aspartic acid mixtures showed a tendency to increase first and then decrease with increasing the amount of aspartic acid.However,gelatinization temperature of dry heat-treated corn starch-lysine mixtures increased with increasing the amount of lysine.Increasing the amount of amino acids also promoted a tighter and more ordered crystal arrangement inside starch granules,which could inhibit the short-term retrogradation and reduce the digestibility of starch.This study can be used as a new method for corn starch modification and provide a reference for the production of modified starch.