Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 5/1/2004
Publication Date: 7/11/2004
Citation: Geveke, D.J., Brunkhorst, C. 2004. Radio frequency electric fields inactivation of escherichia coli in orange juice. Paper No. 32-10. Interpretive Summary:
Technical Abstract: The nonthermal process of radio frequency electric fields (RFEF) has been shown to inactivate bacteria in apple juice at moderately low temperatures, but has not been applied to other juices. The objective of this study was to extend the RFEF process to inactivate bacteria in orange juice. An 80 kW RFEF system was used to process pulp free orange juice at a flow rate of 1.4 l/min. Escherichia coli K12 in the juice was exposed to electric field strengths of 15 and 20 kV/cm at frequencies ranging from 21 to 40 kHz. Following treatment at an outlet temperature of 65 C, the population of E. coli was reduced by 3.3 log, relative to the control. Increasing the electric field strength and temperature and decreasing the frequency enhanced the inactivation. The results of the present study provide the first evidence that the RFEF process inactivates bacteria in orange juice at moderately low temperatures.