Effect Of Microwave Reheating On Rice Quality

This study used rice as the research object. After using three differenttechniques of pre-ripeness, the rice was cooked again imitating the changepatterns of storage time and temperature in motor train unit. By comparingthe degree of retrogradation, texture, moisture, content of amylose andmicrostructure, indicated the effect of quadratic microwave on quality ofrice. On the other side, the study aim to optimize the processing techniqueof rice in microwave combo and to provide theoretical foundation toproduction of rice in microwave combo.The results showed that:1. The physicochemical properties, molecular structure, and crystaltexture of rice had a significant change after quadratic microwave.Specially, different scales of pre-ripeness rice had a decrease in degree ofretrogradation, increase in texture, and the amount of soluble amylose.Furthermore, along with the storage time, moisture content and texturedecreasing significantly, the iodine blue value and degree of retrogradationincreased. At the same time, the quality of the rice decreased to a certaindegree. The speed of retrogradation of rice stored in4was faster than itstored in-18.2. The study found that water-bath and microwave mixed technology combined the common advantage between water-bath and microwave bycomparing the effect of water-bath technology, microwave technology, andmixed technology in rice. It assumed that in the interval of time water bathsoaked the rice starch molecules swell, and sufficient water within thegrain resulting in the maintained within the grain moisture after microwavereheating. The viscosity and flexibility of the rice had been improved inthe microwave heating process, at the same time as sufficient water toreduce the starch and protein cross-linking, reduced hardness, to ensure agood chewing character.The study aimed to compare the effect of these6processingtechniques to the effect of conventional water bath heating on texturequality of rice, such as hardness, tackiness, elasticity, coherence and chewby using texture analyzer, water content and microstructure. The resultshowed that the optimized processing technique was heating the rice in60for30min in water-bath, cooling down in25for30min andheating for6min by using400w microwave. By doing so, the rice innutritional meal that stored in4could maintain the best quality bymicrowave reheating after14days shelf life.