【摘要】 以大米为原料,采用2450MHz微波和常规方法(水浴)加热大米,利用快速黏度分析仪(RVA),分析比较常规加热、微波加热及混合加热后大米黏性的变化,为热处理后大米的深加工及微波技术的应用提供基础数据。结果表明,经单独的水浴、微波或水浴-微波混合加热后,大米糊的黏度下降,热糊稳定性和冷糊稳定性上升。支链淀粉含量较高的大米对热作用较敏感,热处理后黏度变化较大。使用水浴-微波混合加热大米时,随着微波能耗的升高,大米糊峰值黏度、最终黏度、回升值和糊化温度上升,降落值下降,水浴预热的温度较高时,其变化的程度较大。提出了能较好保持大米品质的混合加热方法,即将大米用水浴预热到55℃,再用强度为22～50W·min/g的微波处理的混合加热较单独加热方式(水浴或微波)有利于大米品质的保持。更多还原

【Abstract】 Effect of heating methods (waterbath heating and microwave heating at 2450MHz) on viscosity of rice was studied by using Rapid Visco Analyzer (RVA) for comprehensive utilization of rice after heating and application of microwave technology. Viscosity decreased when waterbath, microwave and waterbath-microwave combined heating heated rice. Warm and cool stability of the rice paste was enhanced after heating. Rice with higher amylopectin content was more susceptive to heating and the variation of viscosity was more remarkable. With microwave energy consumption increasing, peak viscosity, final viscosity, setback value and gelatinization temperature of rice paste increased, whereas breakdown value decreased under waterbath-microwave combined heating. The higher preheating temperature of waterbath was, the more significantly RVA properties variation would be in the scope of the experiment. Rice quality could be well maintained by waterbath preheating to 55℃ first and then microwaving with 22~50W·min/g energy consumption.更多还原