Sterilization of Yakju(Rice Wine) Using a Batch-type High Voltage Pulsed Electric Field System

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  • Kim, Su-Yeon (Department of Food and Bioengineering, Kyungwon University) ;
  • Park, Young-Seo (Department of Food and Bioengineering, Kyungwon University) ;
  • Mok, Chul-Kyoon (Department of Food and Bioengineering, Kyungwon University)
  • 김수연 (경원대학교 식품생물공학과) ;
  • 박영서 (경원대학교 식품생물공학과) ;
  • 목철균 (경원대학교 식품생물공학과)
  • Published : 1999.10.31

Abstract

Yakju(rice wine) was sterilized with high-voltage pulses of short time on a batch pulsed electric field(PEF) system. The initial microbial counts of Yakju were 7.52 X $10^4\;CFU/mL$ for total aerobes, 2.20 X $10^4\;CFU/mL$ for lactic acid bacteria and 7.08 X $10^4\;CFU/mL$ for yeasts. The pH, acidity and electric conductivity of Yakju were 3.36, 0.462% and 1.24 mS/cm, respectively. Yakju was treated with 2-250 of pulses exponential-wave formed electric pulses under the field strength of 12.5-25 kV/cm. The critical strengths of the electrical field for the sterilization of Yakju were 7.5 kV/cm for total aerobes, 8.5 kV/cm for lactic acid bacteria and 6.5 kV/cm for yeasts. Logarithmic survival rates decreased linearly at low pulse number, but curvilinearly at high pulse number. The PEF sterilization kinetics of Yakju could be analysed by In s = In A-k In (n) and the sterilization rate constant increased with electric field strength and the size of target microorganisms. No changed in pH, acidity, and the growth of microorganisms were found in the PEF treated Yakju during the storage for 6 weeks at both $4^{\circ}C$ And $30^{\circ}C$.

Keywords

Yakju;pulsed electric field;sterilization