Food Science and Preservation (한국식품저장유통학회지)

The Korean Society of Food Preservation (한국식품저장유통학회)
권호 표지

Effects of gamma irradiation on the microbiological and general quality characteristics of fresh yam juice

감마선 조사 마(Yam)즙의 미생물학적 및 일반품질 특성

  • Song, Hyun-Pa (Department of Radiation Biotechnology, Korea Atomic Energy Research Institute) ;
  • Kim, Bok-Duck (Department of Nutrition and Culinary Science, Hankyong National University) ;
  • Shin, Eun-Hye (Department of Radiation Biotechnology, Korea Atomic Energy Research Institute) ;
  • Song, Du-Sup (Department of Radiation Biotechnology, Korea Atomic Energy Research Institute) ;
  • Lee, Hyun-Ja (Department of Nutrition and Culinary Science, Hankyong National University) ;
  • Kim, Dong-Ho (Department of Radiation Biotechnology, Korea Atomic Energy Research Institute)
  • 송현파 (한국원자력연구원 정읍방사선과학연구소) ;
  • 김복덕 (국립한경대학교 영양조리과학과) ;
  • 신은혜 (한국원자력연구원 정읍방사선과학연구소) ;
  • 송두섭 (한국원자력연구원 정읍방사선과학연구소) ;
  • 이현자 (국립한경대학교 영양조리과학과) ;
  • 김동호 (한국원자력연구원 정읍방사선과학연구소)
  • Received : 2010.03.22
  • Accepted : 2010.07.16
  • Published : 2010.08.30
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Abstract

Pasteurization by radiation was performed to improve the microbiological quality of fresh yam juice. Samples were irradiated at doses of up to 5 kGy and microbiological, physicochemical, and sensory qualities were investigated during storage at 5oC for 8 days. Total aerobic bacterial, coliform bacterial, and yeast and mold counts in pre-irradiation samples were 7.09, 6.91, and 3.42 log CFU/g, respectively. Total aerobic bacterial and coliform counts fell significantly, in a dose-dependent manner, after irradiation, and these organisms were completely eliminated after 1 day of storage when 3 kGy or 5 kGy of radiation was applied. Yeast and molds were eliminated by irradiation at 3 kGy. Irradiation reduced sample viscosity. The $L^*$ value decreased after irradiation, whereas the $b^*$ value rose. Sensory evaluation testing revealed no significant difference between control samples and those irradiated with 1 kGy, except in color and texture, but sensory scores fell when irradiation of 3 kGy or over was employed, except in the taste domain. The results indicate that gamma irradiation with 1 kGy is effective to ensure the microbiological safety of fresh yam juice, without significant alteration in sensory characteristics, although further work should seek to reduce the detrimental effects of irradiation.

마즙의 위생성 및 보존성 향상을 목적으로 0, 1, 3 및 5 kGy의 선량으로 감마선을 조사하고 $5^{\circ}C$에서 보관하면서 8일간 마즙의 미생물학적, 일반품질 및 관능평가를 실시하였다. 마즙의 호기성세균 및 대장균군은 각각 1.26 및 1.34 kGy의 $D_{10}$값을 보였으며, $5^{\circ}C$ 저장에 따라 3 및 5 kGy 조사구의 경우 검출한계 이하의 균수를 유지하였다. 효모 및 곰팡이의 D10값은 0.29 kGy로 일반호기성균 및 대장균군 보다 감마선에 높은 감수성을 보였으며, 모든 조사구의 경우 냉장저장에 따라 검출한계 이하의 균수를 나타내었다. 감마선 조사에 따른 마즙의 점성은 조사 선량이 증가할수록 유의적으로 감소하는 경향을 나타내 마즙 특유의 고점성으로 인한 단점을 보완하여 음용의 편이성을 증대시킬 수 있을 것으로 사료된다. 마즙의 $L^*$값은 감마선 조사에 따라 감소하였으나 냉장저장에 따른 $L^*$값의 감소율은 비조사구가 가장 켰으며, $b^*$값 또한 감마선 조사에 의해 증가해 갈변이 일어나는 것으로 관찰되었다. 3 및 5 kGy 마즙은 맛을 제외한 조직감, 색, 냄새 및 전체적인 기호도에서 비조사구보다 유의적으로 낮은 선호도를 보였으며, 1 kGy 조사구는 냄새와 색을 제외하고 비조사구와 차이가 없었다. 이상의 결과를 종합하여 볼 때, 조사에 따른 색의 변화를 최소화하기 위한 항산화제 첨가 또는 포장방법 및 방사선 조건 등에 대한 좀 더 다양한 연구가 보완되어야 할 것으로 판단되며, 약 1 kGy 감마선 조사와 냉장저장을 병행함으로써 마즙의 품질을 향상시킬 수 있을 것으로 사료된다.

Keywords

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