以福临门水晶米为原料,研究了将其加工成方便米饭所需的浸泡时间、加水量、蒸煮时间以及蒸汽蒸煮过程中浸泡米和不浸泡米的蒸汽蒸煮动力学。实验得到的前期生产条件为:在20℃的自来水中浸泡约1 h可充分吸水;生产200 g米饭所需的加米量和加水量分别约为75 g和125g;在常温常压蒸汽蒸煮条件下,浸泡米和不浸泡米煮熟时间分别为18 min和26 min,浸泡使大米的蒸汽蒸煮时间缩短了约8 min。方便米饭蒸汽蒸煮动力学研究结果表明:浸泡米和不浸泡米的蒸煮过程都符合一级动力学反应方程;浸泡米有2个蒸煮速率常数而不浸泡米有3个蒸煮速率常数,且各阶段速率常数的大小也不相同,这主要是由于浸泡米在蒸煮前已充分吸水,且在各个阶段它们发生的物理化学变化及蒸煮速率的限制因素均有不同。

In this study,Fook Lam Moon Crystal-Rice as a raw material to produce instant rice,the presoaking time,water quantity and cooking time required for instant rice production,and the steam cooking kinetics of pre-soaked and unsoaked rice during the process of the steam cooking were studied.The initial production conditions we obtained from experiments were that about 1 h was needed for complete water absorption at 20℃ in trap water,and the quantity of rice and water required for producing 200 g rice were about 75 g and 125 g,respectively.And at room temperature and pressure conditions of steam cooking,the cooking time of presoaked and unsoaked rice were about 18 min and 26 min,respectively,it indicated that presoaking of rice before cooking reduced the cooking time about 8 min.Results from steam cooking kinetics study showed that both presoaked rice and unsoaked rice were in line with the first-order kinetics equation during the steam cooking process,and cooking of presoaked rice two rate constants were observed while in the case of unsoaked rice three cooking rate constant were observed.Further,at the various stages during cooking the sizes of cooking rate constants were different,which was mainly due to the complete water absorption of presoaked rice before cooking and the difference of physical and chemical changes and the limiting fac-tors of cooking rate at the various stages.The research process and results give a reference for the standardization of the initial production conditions and the improvement of the production process of the instant rice.