The residence time of the fastest particle through in ohmic heater should be known with a high degree of reliability to calculate the minimum lethality delivered to the product inside the heater. Many methods are available for the determination of residence time distribution (RID) of particles inside heating systems, but the main limitation in all these methods is their inability to detect multiple particles. Radio frequency identification (RFID), which offers the possibility of tracking multiple particles inside the system, was used to measure the RTD of analog chicken particles in chicken chowmein inside an ohmic heating system. Results showed that the residence time of the fastest RFID tag embedded tracer inside the heater was as expected, higher than that associated with the laminar flow of a fluid in a tube, which is accepted by regulators in process filings. The experiment demonstrated that RFID could be successfully used to measure RTD under aseptic conditions and offers in innovative, time-saving technique for tracking multiple particles. (C) 2009 Elsevier Ltd. All rights reserved.