Nonthermal Pasteurization of Takju using Batch High Voltage Pulsed Electric Fields with Exponential Decay Pulse

Abstract

Makgeolli, a traditional Korean turbid rice wine, was treated with pulsed electric fields (PEF) for the purpose of a development of a new cold pasteurization processes. Inactivation of yeast in the makgeolli increased with increase in intensity of the electric field strength and treatment time. The initial yeast count of the makgeolli was 2×10 cfu/ ml. A reduction of 2D was obtained at 30 kV/cm and 256 exponential decay pulses at room temperature. The combination of PEF and conventional thermal treatment inactivated the yeast more effectively. Reductions of up to 8D were observed when the makgeolli was treated with PEF of 20 kV/cm and 256 pulses at 50C. The inactivation of the yeast in makgeolli increased with an increase in alcohol content. When the alcohol content of the makgeolli increased to 12%, PEF treatment with 30 kV/cm and 256 pulses resulted in a 4.8D reduction of yeast. No changes in pH, acidity, or the growth of yeast were observed in the PEF treated makgeolli during storage at 4C for 4 weeks.