Liu Chai, Shen Liuyang, Liu Huiran, Gong Xue, Liu Chenghai, Zheng Xianzhe, Zhang Shuo, Yang Chen
College of Engineering, Northeast Agricultural University, Harbin 150030, China.
College of Light Industry, Harbin University of Commerce, Harbin 150028, China.
Foods. 2023 Aug 2;12(15):2938. doi: 10.3390/foods12152938.
The taste quality of ready-to-eat rice is influenced by the uniformity of temperature distribution during microwave reheating. The temperature distribution uniformity of ready-to-eat rice loaded in a rectangular lunch box is investigated under microwave reheating. The results show that with a 10-80 °C temperature increase in the ready-to-eat rice, the thermal conductivity increases, dielectric constant, and specific heat increase and then decrease, while the dielectric loss factor decreases and then slightly increases. The microwave-heating process of ready-to-eat rice exhibits a clear 'corner effect', and the observed 'hot spot' results in poor temperature uniformity in ready-to-eat rice. A metalized packaging structure design is subsequently proposed to ameliorate the temperature non-uniformity. According to comparative results of four metalized packaging forms, the spray film volume and film thickness corresponding to film volume are developed as 3.5×10-4 mL/mm2, 0.30 mm, respectively, which levels off the difference in temperature to improve the temperature distribution uniformity of ready-to-eat rice by microwave reheating.
即食米饭的口感质量受微波加热过程中温度分布均匀性的影响。研究了矩形饭盒中装载的即食米饭在微波加热下的温度分布均匀性。结果表明，在即食米饭温度升高10 - 80°C的过程中，热导率增加，介电常数和比热容先增加后降低，而介电损耗因子先降低后略有增加。即食米饭的微波加热过程呈现出明显的“边角效应”，观察到的“热点”导致即食米饭温度均匀性较差。随后提出了一种金属化包装结构设计来改善温度不均匀性。根据四种金属化包装形式的对比结果，对应膜体积的喷涂膜体积和膜厚度分别为3.5×10 - 4 mL/mm2、0.30 mm，这减小了温度差异，以改善即食米饭微波加热时的温度分布均匀性。
