Real-Time Quality Assessment of Liquid Food Products Using an LC-Based Capacitive Sensing System

This paper discusses the realization of an LCsensing system with capabilities for the assessment of liquid-food-product quality in a real-time and non-invasive manner; two foods that drew emphasis were milk and juice. The system consists of a parallel plate capacitive sensor working with the LC tank circuit that is designed to reflect changes in capacitance due to variations arising in the dielectric property of the sample with respect to factors of fat content, acidity, or adulteration, which are the critical parameters of quality concerning the liquid food product. The capacitive sensor was fabricated from a polyester substrate with coplanar electrode design and a guard electrode to minimize external interferences and thus ensure precision in measurement. On measuring the shift in the resonant frequency of the LC circuit, the proposed system detects the change in dielectric properties of the milk and juice sample measured that correlates to their chemical compositions and quality attributes. The system could detect fat content, acidity, and adulteration levels with sensitivity, accuracy, and reliability. With a non-invasive approach for real-time measurement, the device is best suited for quality control in food and beverage manufacturing. Additionally, the system is compact, cost-effective, and requires minimal sample preparation, making it a practical tool for industrial applications. The proposed technology has potential for integration with IoT-based platforms for continuous monitoring The findings further validate that this technology could be a low-cost but exceedingly robust solution for food safety and regulatory compliance, paving the way for broader implementation in the food industry.