【作者】 吕俊峰； 郭文川；

【Author】 Lü Junfeng1,2, Guo Wenchuan 1,3※ (1.Northwest A&F University, College of Mechanical and Electronic Engineering, Yangling Shaanxi , 712100, China; 2.Chongqing Creation Vocational College, Institute of Machinary and Electronics, Chongqing, 402160, China ; 3.Shaanxi Agricultural Equipment Engineering Technology Research Center, Yangling Shaanxi,712100, China)

【机构】 西北农林科技大学机械与电子工程学院； 重庆科创职业学院机械与电子工程学院； 陕西省农业装备工程技术研究中心；

【摘要】 本文以食用玉米油为对象,采用同轴探头技术测量了200～4500MHz内高温加热(120～240℃,3～15h)后的玉米油的微波介电特性,同时测量了品质指标。研究结果表明,未加热玉米油的相对介电常数和介质损耗因数随频率的变化而变化,而加热处理过的油的相对介电常数和介质损耗因数基本不随频率而变。加热处理使同频率下玉米油的相对介电常数减小,介质损耗因数增大。加热温度、时间对介电参数值有一定的影响。当温度大于180℃时,随着加热时间的延长,玉米油的酸价迅速增大,当温度为120℃时,加热时间对过氧化值有明显的影响。本研究有助于了解温度和时间对玉米油微波介电特性和品质指标的影响,为微波介电特性在油品质检测中的应用提供试验基础。更多还原

【Abstract】 The open-ended coaxial technology was used to measure microwave dielectric properties of heated edible corn oil at 120～240℃ for 3～15h over the frequency range from 200 to 4500MHz, along with quality indexes of heated oil. The results show that the relative dielectric constant of corn oil without heating changes with frequency, while it keeps constant generally when the oil was heated. The dielectric constant of heated oil is higher and the loss factor is lower than that of unheated oil. The temperature and time also influences oil permittivities. When the temperature is higher than 180℃ , the acid value increases with heated time, but the time has obvious affect to peroxide value when the temperature is 120℃ . The study is helpful to understand the influence of heating temperature and time on microwave permittivities as well as qualities of edible oils. It offers basis for applying microwave dielectric properties in oil quality detection.更多还原