Radiofrequency Absorbance as a Novel Concentration Indicator in Sucrose Aqueous Solutions

Microwave-based methods have been used for years to monitor processes, tests, and substance mixtures. Solutions must preserve sample integrity and avoid time-consuming procedures to scale inline industrial applications and promote on-field tests. Today, testing procedures use portable, cost-effective devices operating on wide frequency ranges to perform low-power, wide-band microwave dielectric spectroscopy. This paper describes a proof of concept using SDR technology to match all these requirements. A prototype was tested for measuring sucrose-in-water solutions at different concentrations, which resulted in a novel concentration indicator based on radiofrequency absorbance. This application is critical for in-line monitoring and on-field testing in the food and beverage industries. The proposed method delivered robust, replicable, and reliable results. High levels of significance (> 99%) were achieved in statistical tests in the frequency range of 4 125 to 4 410 MHz. The indicator was shown to be sensitive to concentrations below those reported in the literature and could be easily integrated into non-destructive early chemical evaluation for food quality and production monitoring or into on-field testing devices, to name some applications.