Korean Journal of Food Science and Technology (한국식품과학회지)

Korean Society of Food Science and Technology (한국식품과학회)
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Changes in Quality of UV Sterilized Takju during Storage by Honeycomb Type-UV Sterilizer

허니컴방식 UV 살균기를 이용한 살균 탁주의 저장 중 품질변화

  • Lee, Jang-Woon (Department of Food Science and Technology, Seoul National University of Technology) ;
  • Jung, Jin-Joo (Department of Food Science and Technology, Seoul National University of Technology) ;
  • Choi, Eun-Ju (Department of Food Science and Technology, Seoul National University of Technology) ;
  • Kang, Sung-Tae (Department of Food Science and Technology, Seoul National University of Technology)
  • 이장운 (서울산업대학교 식품공학과) ;
  • 정진주 (서울산업대학교 식품공학과) ;
  • 최은주 (서울산업대학교 식품공학과) ;
  • 강성태 (서울산업대학교 식품공학과)
  • Published : 2009.12.31
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Abstract

A cylindrical ultraviolet (UV) sterilization system was developed for decreasing microorganisms in takju. The takju was passed through 110 strips of honeycomb-type teflon tubing with 9 UV lamps (1,395 W) set between the teflon tubes. Thus, during passage, the takju was effectively exposed to the UV rays without loss. In terms of the overall quality aspects of the takju, the optimum sterilization condition was set for 4 min at 2 L/min. A 2-3 log cycle decrease in viable cell numbers of total bacteria and fungi was observed at this operating condition. Quality changes in the UV-sterilized takju were examined via UV irradiation of samples followed by storage at 30oC for 8 days. To evaluate the quality changes, pH, amino nitrogen content, acidity, reducing sugar content, and viable cell numbers of total bacteria and fungi were measured. Increases in pH, acidity, and amino nitrogen content were observed in both the takju control and UV sterilized takju with increasing storage time. However, reducing sugar content was decreased in both samples. The L, a, and b values of the control takju and UV sterilized takju showed similar trends over the storage period. Viable cell numbers of fungi did not change in the control or UV sterilized takju during storage, showing approximately $10^8\;CFU/mL$ and $10^4-10^5\;CFU/mL$, respectively. In addition, viable cell numbers of total bacteria remained lower in the UV sterilized takju over 4 days compared to the non-sterilized takju.

탁주를 효과적으로 살균하기 위해서 110가닥의 테프론 튜브와 9개의 자외선(UV) 램프(1,335W)로 구성된 허니컴방식의 UV 살균기를 제작하고 탁주를 순환시켜 살균하여 미생물 살균효과 및 저장 중의 품질변화를 평가하였다. 허니컴방식의 UV 살균기에서 유속 2 L/min에서 4분 동안 탁주를 순환시킨 조건은, 일반세균 및 진균을 2-3 log cycle 감소시키면서 관능적으로 양호한 품질을 얻을 수 있는 최적의 살균조건으로 판단되었다. 이 조건에서 살균 처리한 탁주를 $30^{\circ}C$에서 8일간 저장하면서 pH, 아미노태질소 함량, 환원당 함량, 산도, 그리고 일반세균수 및 진균수의 변화를 측정하였다. pH, 산도, 아미노태 질소 함량은 저장 중에 생탁주와 UV 살균탁주에서 모두 증가하는 경향을 나타낸 반면 환원당 함량은 감소하는 경향을 나타내었다. 또한 생탁주와 UV살균탁주의 L, a, b 값은 저장 중에 매우 유사한 경향을 나타내었다. 저장 중에 UV 살균탁주의 진균은 생육이 억제되었으며 일반세균은 저장 4일째에 생탁주 수준에 도달하였다.

Keywords

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