稻谷陈化过程中限制性氨基酸变化的动力学研究

THE KINETIC STUDIES ON THE CONTENT OF LIMITING AMINO ACIDS DURING RICE AGING

目的:了解稻米在陈化过程中蛋白质营养品质的变化趋势,为有效利用和改善粮食蛋白质营养品质提供理论依据。方法:对稻米陈化过程中赖氨酸和色氨酸含量变化的动力学特征进行了研究。结果:赖氨酸与色氨酸含量变化均符合动力学一级反应,反应速率与温度的关系分别为lnk=ln(2.05×107)-6929.3/T与lnk=ln(1.18×105)-5426.9/T,活化能分别为Ea=57.61 kJ/mol与Ea=45.12 kJ/mol。结论:陈化过程中稻米赖氨酸、色氨酸含量均减少,且色氨酸较赖氨酸更容易被氧化变质,降低了它的蛋白质营养品质。

Objective:To study the changes of rice protein and its limiting amino acids in storage and provide theoretical basis for utilizing and improving its nutritive value. Methods:During rice aging , the kinetic properties of Lys and Trp were studied. Results:The changes of Lys conformed to kinetics first-class reaction, lnk=ln(2.05×107)-6929.3/T and Ea(activation energy)=57.61 kJ/mol, while those of Trp conformed to first-class reaction, lnk=ln(1.18?05)-5426.9/T and Ea=45.12 kJ/mol. Conclusion:Both Lys and Trp contents decreased significantly in storage, Trp worse than Lys. The nutritive value of rice protein then decreased.