Model foods as chemical marker carriers are needed to evaluate the heating patterns and location of hot and cold spots in developing microwave assisted thermal sterilization (MATS) processes. Previous research on model food development has been conducted for high moisture foods, with limited data on medium moisture foods (20–60% water). This research aimed to determine the dielectric properties (dielectric constants and loss factors) and penetration depths of rice grain (RG) and rice flour gel (RFG) model foods with moisture contents between 50 to 60% (wet basis) and of cooked rice (CR) over a frequency range of 300–3000 MHz at temperatures from 20 to 121 °C. The dielectric properties of rice models with 0% salt and 0.5% d-ribose closely matched the properties of CR; this indicated that rice model foods could be used to emulate CR for heating pattern and cold/hot spot detection in the development of MATS processes at 915 MHz and 2450 MHz.

Therefore, rice model foods developed in this research could be useful in the future for the food companies, in order to visualizing the heating pattern and determining the location of cold and hot spots during MATS process of medium moisture foods, such as rice, pasta or macaroni used as main ingredient in ready-to-eat meal products.

需要模型食品作为化学标记载体，以评估微波辅助热灭菌（MATS）工艺开发过程中的加热方式以及热点和冷点的位置。以前已经对高水分食品进行了模型食品开发的研究，但有关中水分食品（20-60％的水）的数据有限。这项研究旨在确定水分含量在50％至60％（湿基）之间的米粒（RG）和米粉凝胶（RFG）模型食品以及煮熟的米饭的介电性能（介电常数和损耗因子）和渗透深度CR）在300至3000 MHz的频率范围内，温度范围为20至121°C。含0％盐和0.5％d的水稻模型的介电性能-核糖与CR的性质紧密匹配；这表明在915 MHz和2450 MHz的MATS工艺开发中，大米模型食品可用于模拟CR，以进行加热模式和冷/热点检测。

因此，本研究开发的大米模型食品将来对食品公司很有用，以便可视化中等水分食品（例如大米，面食或大米）的MATS过程中的加热模式并确定冷点和热点的位置。通心粉用作即食餐食产品的主要成分。