Changes in kernel properties, in situ gelatinization, and physicochemical properties of waxy rice with inhibition of starch branching enzyme during cooking

Summary The kernel properties, gelatinisation and physicochemical properties of rice were investigated in a waxy rice Guang‐ling‐xiang‐nuo (GLXN) and its transgenic line GLXN‐RNAi with inhibition of starch branching enzyme I/IIb. The volume swelling, water content and leached material of cooked kernels increased with increasing cooking time, but they were lower in GLXN‐RNAi than in GLXN. The kernels of GLXN‐RNAi were more difficultly gelatinised and disrupted than those of GLXN during cooking. The starch in the exterior of GLXN‐RNAi endosperm was not completely gelatinised. The CA‐type starch of GLXN‐RNAi was more resistant to cooking than A‐type starch of GLXN. The cooked kernels of GLXN‐RNAi had lower rapidly digestible starch and greater slowly digestible starch than those of GLXN. Brown rice flour had higher peak, hot, final and setback viscosities and lower breakdown viscosity in GLXN than GLXN‐RNAi. These results indicated that GLXN‐RNAi kernels exhibited great potential in applications as health foods.