蛋白质与淀粉的相互作用对陈化大米质构特性的影响

EFFCT OF INTERACTION OF PROTEIN AND STARCH ON TEXTURE CHARACTERISTICS OF AGED RICE

以１０种大米为材料研究了在４０℃条件下储藏６个月后蒸煮大米粘度和硬度的变化以及蛋白质的溶解性、蛋白与淀粉相互作用的变化。结果表明，陈化以后蒸煮大米的硬度上升，粘度下降。蛋白质总量基本不变，但是，总蛋白以及清蛋白、球蛋白、醇溶蛋白和谷蛋白的提取率都降低。ＳＤＳ－ＰＡＧＥ电泳图谱显示清蛋白、球蛋白和谷蛋白的高分子量亚基含量增多，低分子量亚基含量减少，非淀粉粒蛋白与淀粉的相互作用在大米陈化过程中增加。通过对６０ＫＤ淀粉粒蛋白含量高的４种大米的研究表明，大米陈化过程中淀粉粒蛋白与淀粉的相互作用增加，这种变化与蒸煮大米粘度变化的相关性显著（ｐ＝００５），因此，淀粉粒蛋白与淀粉相互作用增加可能是导致陈化大米蒸煮后粘度降低的一个重要原因。

Influence of storage on texture of cooked rice proteins and the interaction of protein and starch has been studied in grains of ten rice varieties.The hardness increased and stickness decreased after storage for 6 months at temperature of 40℃.Although no change in total protein content occurred,solubility of total proteins and their sub fractions all decreased .The low molecular weight subunits in albumin,globulin and oryzenin all declined while high molecular weight subunits increased.The interaction of nonstarch granule protein and starch increased during storage.Four varieties of rice were studied for the ability of starch granule associated protein (SGAP) to bind starch.The interaction also increased,and the correlation between the increasing of stickness and interaction was positive significantly ( P =0.05) which indicated that the increasing of interaction between SGAP and starch during storage may be one of the main factors which leaded to the lower stickness of aged rice