Multi-Modal Sensing Platform for Continuous Analysis of Maple Syrup in Production Process

In this work, we propose a new multimodal method/platform for continuous maple syrup °Brix monitoring and color grading during the production process. It is based on different detection methods such as electrical impedance, electrochemical sensing and optical sensing. First, using electrochemistry sensing, the results of maximum detected current in obtained Voltammogram with cyclic-voltammetry (CV) analysis and generated currents for chronoamperometry experiments presents a high standard deviation higher than 50%. In addition, we report the impact of the temperatures on previously mentioned sensing techniques. We have observed that electrochemistral sensor with commercial electrodes in our experimental conditions did not provide reliable measurement for maple syrup industrial process for °Brix monitoring. When using electrical impedance sensing method, a polynomial fitting relationship was established between the electrical impedance and °Brix with a high fitting index (R²) of 0.895. Furthermore, an impedance offset must be considered when temperature is changing. Also, an optical sensor was used to detect the maple syrup grade. As the grade depends on the light transmission percentage through a known thickness of solution, a photodiode detector and a LED were used as grade sensor. Many LEDs with different wavelengths (green, yellow, red, blue and infrared) were tested on different maple syrup grades. Obtained results show that green LED is the most suitable one for maple syrup grade detection which can lead to a linear fit with high fitting index (R²) of 0.963 between voltage response of the photodiode detector and the light transmission which is converted to a maple syrup grade.