Department of Food Science, University of Tennessee, Knoxville, TN, USA.
Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN, USA.
Food Res Int. 2022 Apr;154:110985. doi: 10.1016/j.foodres.2022.110985. Epub 2022 Feb 12.
The solid-state microwave generator is promising to replace magnetron as a power source in domestic ovens for its precise and flexible control over a wide range of operational parameters and its potential to improve heating performance. Shifting frequency during microwave heating, either orderly or using complementary heating patterns, has yielded better heating performance than traditional single-frequency heating. This study developed three online frequency shifting strategies (orderly, pre-determined complementary, and dynamic complementary) that simultaneously collected heating performances and provided closed-loop feedback through customized algorithms to control the frequency shifting during the microwave heating processes. Each algorithm was implemented and tested on two model foods with different dielectric properties (gellan gel and mashed potato). The three frequency shifting algorithms had similar frequency sweeping processes but considerably different frequency shifting procedures for different replications and food products. The dynamic complementary frequency shifting strategy simultaneously evaluated the heating performance and determined the next-step complementary frequency. The method had shown better heating uniformity than the orderly and pre-determined complementary frequency shifting strategies. The dynamic complementary frequency shifting strategy could accommodate different food products and can be incorporated into future smart microwave ovens.
固态微波发生器有望取代磁控管成为家用烤箱的电源，因为它可以精确、灵活地控制广泛的操作参数，并有可能改善加热性能。在微波加热过程中改变频率，无论是有序的还是使用互补的加热模式，都比传统的单频加热具有更好的加热性能。本研究开发了三种在线频率切换策略（有序、预定互补和动态互补），这些策略通过定制算法同时收集加热性能，并提供闭环反馈，以控制微波加热过程中的频率切换。每个算法都在具有不同介电特性的两种模型食品（凝胶和土豆泥）上进行了实施和测试。三种频率切换算法具有相似的频率扫描过程，但对于不同的重复和食品产品，频率切换过程有很大的不同。动态互补频率切换策略可以同时评估加热性能并确定下一步的互补频率。该方法与有序和预定互补频率切换策略相比，显示出更好的加热均匀性。动态互补频率切换策略可以适应不同的食品产品，并可纳入未来的智能微波炉中。
