粳稻脂肪含量对淀粉热力学特性及米饭食味品质的影响

以江苏省种植的直链淀粉含量和蛋白质含量相近的20个粳稻品种为实验材料，采用聚类分析将稻米脂肪含量分为低脂、中脂和高脂三种类型，探究不同脂肪含量稻米回生过程中淀粉热力学特性、米饭食味品质、质构特性变化差异。结果表明，中脂类型品种未脱脂米粉具有较高的糊化热焓值、较低的回生热焓值和回生度，米饭食味品质和质构特性显著优于低脂类型品种和高脂类型品种。与0天米饭相比，回生1天后中脂类型品种米饭质构特性未发生显著劣变，而低脂和高脂类型品种米饭质构特性发生极显著劣变；回生7天后，三类品种米饭质构特性均发生极显著劣变。表明中脂类型品种稻米抑制淀粉糊化和回生的能力更强，更能延缓回生过程中米饭质构特性与食味品质的劣变。

Effect of lipid content on starch thermodynamic properties and taste quality in japonica rice

Using 20 japonica rice varieties with similar amylose content and protein content planted in field in Jiangsu Province as experimental materials, the lipid content of rice was divided into three types, low lipid content, medium lipid content and high lipid content by cluster analysis, to explore the differences of starch thermodynamic characteristics, rice taste quality and texture characteristics in the process of rice retrogradation among different types. The results showed that, the non defatted rice flour of middle lipid varieties had higher gelatinization enthalpy and lower regeneration enthalpy and regeneration degree, the eating quality and texture characteristics of rice were significantly better than those of low lipid and high lipid varieties, and the differences of taste quality and texture characteristics between low lipid and high lipid varieties were not significant. Compared with 0-day steamed rice, the texture characteristics of steamed rice for mid-lipid varieties did not significantly deteriorate after 1 day of retrogradation, while the texture characteristics of steamed rice for low lipid and high lipid varieties significantly deteriorated, and that of steamed rice for three types varieties had significant deterioration after 7 days. The results showed that rice varieties with medium lipid content had stronger ability to inhibit starch gelatinization and retrogradation, and could delay the deterioration of texture and taste quality of steamed rice during retrogradation.