脂肪酸对糯米淀粉热特性的影响

Effect of Fatty Acids on Thermal Properties of Waxy Rice Starch

[目的]研究脂肪酸对糯米淀粉热特性的影响。[方法]利用紫外分光光度计和差示扫描量热仪对硬脂酸、油酸与糯米淀粉形成复合物的性质进行测定。[结果]试验表明,硬脂酸和油酸均可与糯米淀粉形成复合物,且硬脂酸比油酸更易与糯米淀粉复合。随着脂肪酸用量的增加,复合指数表现出上升趋势,当硬脂酸、油酸添加量分别为7%、5%时,复合指数达到最大。DSC分析表明,添加硬脂酸、油酸的糯米淀粉起始糊化温度、峰值温度以及糊化焓均低于糯米原淀粉。随着脂肪酸用量的增加,糯米淀粉的糊化焓值显著减小,老化率明显降低。[结论]试验可为研究速冻食品冻藏期间主要成分之间的相互作用以及改善糯米粉在食品加工中的品质特性提供理论参考。

[ Objective ] To study effects of fatty acids on thermal properties of waxy rice starch. [ Method] Utraviolet spectrophotometer and differential scanning calorimetry were utilized to measure complexes formed by waxy rice starch with palmitic acid and stearic acid. [ Result] The results showed that palmitic and stearic acid could both form complexes with waxy rice starch. And palmitic acid preferentially integrated with waxy rice starch compared with stearic acid. With the increase of fatty acids, complex index increased and the complex index reached maximum when palmitic acid and stearic acid was 7% and 5%. Thermal studies with DSC suggested that onset temperature, peak temperature and gelatinization enthalpy of waxy rice starch added with palmitic acid and stearic acid were lower than waxy rice starch. The gelatinization enthalpy of waxy rice starch significantly decreased with the increase of fatty acid. Retrogradation rate evidently decreased. [ Conclusion] The study could provide theoretical reference for studying interaction of main components of quick-frozen food and improving properties of waxy starch in food processing.