Feasibility of RF Sensor Application for On-line Monitoring of Tomato Paste Processing

On-line monitoring of fresh tomato paste processing was done using two radio frequency (RF) sensors resonant at 85 and 110 MHz. Fresh tomato juice with soluble solid content of about was evaporated up to and diluted down to about again with a pilot scale evaporator. The RF sensors were installed in a processing pipe and monitored. The pastes at a specific level were sampled and analyzed for physical properties such as soluble solid content and viscosity. The relationships between sensor outputs and measured physical properties were analyzed. Analysis results showed RF sensor is feasible to apply on-line monitoring of tomato paste processing.