The desalted cod industry needs a suitable and reliable control system to check the desalting point of cod in order to provide a safe and high-quality product. The growth of the industries that are interested in a non-contacting, real-time control, encourages the development of new methods based on low-power radiation, such as dielectric spectroscopy. These techniques use the modification of wave parameters at some specific frequencies to provide information of the compositional characteristics of foods. In this work, cod parallelepipeds were desalted at 5 °C by immersing them in distilled water for different desalting times (15 and 30 minutes and 1, 2, 4, 6, 8, 12, 24 and 48 hours). Dielectric Spectroscopy studies have been performed on cod samples in the frequency range 200 MHz-20 GHz. The dielectric properties were measured using a coaxial probe (Agilent 85070E) connected to a Network Analyzer (Agilent E8362B) immediately after removing the cod samples from their desalting solutions. After desalting, the cod samples were separated from their desalting solutions and kept in repose for 24 h at 5 °C after which some of their physical properties were measured. This experimental procedure ensures that those properties have already reached their final values. Good correlations were found between the quality properties of the cod samples (aw, xw, zNaCi and xNaC) after 24 h and their loss factor (e’) measured at 10 GHz just before leaving them in repose, showing the feasibility of an in-line control system for cod desalting process at that frequency.

中文翻译：

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使用介电光谱监测鳕鱼的脱盐过程

鳕鱼脱盐行业需要一个合适且可靠的控制系统来检查鳕鱼的脱盐点，以提供安全、优质的产品。对非接触式实时控制感兴趣的行业的发展鼓励了基于低功率辐射的新方法的开发，例如介电光谱学。这些技术使用在某些特定频率上修改波参数来提供食物成分特征的信息。在这项工作中，鳕鱼平行六面体在 5 °C 下通过将它们浸入蒸馏水中不同的脱盐时间（15 和 30 分钟以及 1、2、4、6、8、12、24 和 48 小时）进行脱盐。已对 200 MHz-20 GHz 频率范围内的鳕鱼样品进行了介电光谱研究。在从脱盐溶液中取出鳕鱼样品后，立即使用连接到网络分析仪 (Agilent E8362B) 的同轴探头 (Agilent 85070E) 测量介电特性。脱盐后，将鳕鱼样品与其脱盐溶液分离，并在 5°C 下静置 24 小时，然后测量它们的一些物理特性。这个实验程序确保这些特性已经达到它们的最终值。在 24 小时后的鳕鱼样品（aw、xw、zNaCi 和 xNaC）的质量特性与其在 10 GHz 下测量的损耗因子 (e') 之间存在良好的相关性，这表明该频率下鳕鱼脱盐过程的生产线控制系统。