Quality Characteristics of Makgeolli during Freezing Storage

냉동저장에 따른 막걸리의 품질특성

  • Lee, Jin-Won (Department of Food & Biotechnology and Food and Bio-industrial Research Center, Hankyong National University) ;
  • Shim, Jae-Yong (Department of Food & Biotechnology and Food and Bio-industrial Research Center, Hankyong National University)
  • 이진원 (한경대학교 식품생물공학과 및 식품생물연구소) ;
  • 심재용 (한경대학교 식품생물공학과 및 식품생물연구소)
  • Received : 2010.11.08
  • Accepted : 2010.11.23
  • Published : 2010.11.30

Abstract

Recently the enhancement and development of makgeolli processing to extend shelf life are constantly accomplished. However, the standardization to restrict microorganisms including cold chain system and sterilizing system has not been established yet. Therefore, the objective of this study was to investigate the storage stability of makgeolli using quick freezing (QF) and slow freezing (SF) storage methods. The storage period was 40 days. Every 10 days, the samples were taken from the quick and slow freezing storage chamber. And then the samples were put into a $10^{\circ}C$ refrigerator for 24 hr to thaw them. The final samples were evaluated for chemical experiments and microbial cell counts. As a result, reducing sugar content was dramatically increased after 10 days for all of the samples. In titratable acidity and color values case, these values did not significantly change by storage time. In case of lactic acid bacteria and yeasts for all the samples, there was a decreasing tendency with storage time. Especially, in case of lactic acid bacteria, the changes from the beginning microbial cell counts ($4.1{\times}10^7$ CFU/mL) for QF and SF after 20 days were $3.6{\times}10^6$ CFU/mL and $1.8{\times}10^4$ CFU/mL, respectively. This result showed that the freezing methods could restrict the microbial growth in makgeolli.

최근 전통 식품에 대한 관심이 증가함에 따라서 우리 나라 고유의 술인 막걸리 소비가 국내에서뿐만 아니라 해외 수출량도 급증하고 있다. 그러나 막걸리의 유통 및 저장 안정성을 증가시킬 수 있는 방법으로는 미생물 제어 기술로서 냉장 유통과 가온 살균에 제한되어 표준화된 기술이 부족한 실정이다. 따라서 본 연구에서는 막걸리 유통기간 연장 방법의 하나로 막걸리를 급속동결(Quick Freezing, QF) 및 완만동결(Slow Freezing, SF)을 하였으며 이에 따른 품질 변화를 실험하였다. 즉, 동결 방법에 따라서 40일간 저장하면서 저장기간 10일 간격으로 시료를 취하여 $10^{\circ}C$에서 24시간 해동시킨 후 이화학 분석 및 미생물 실험을 실시하였다. 그 결과 모든 시료군에 대해서 환원당은 저장 10일째 급격히 증가한 후 저장기간에 따라 지속적으로 증가하였으나, 그 증가폭은 크지 않았다. 산도 및 색도 경우 저장기간에 따라 유의적 차이를 나타내지 않았다. 미생물의 경우 젖산균 및 효모 모두 저장기간이 증가할수록 감소하는 경향을 나타내었다. 젖산균의 경우 초기 젖산균이 $4.1{\times}10^7$ CFU/mL에서 저장 20일째 QF는 $3.6{\times}10^6$ CFU/mL, SF는 $1.8{\times}10^4$ CFU/mL로 나타나 QF 경우보다 SF경우 저장 중 젖산균에 대한 변화가 크게 나타났다. 효모의 경우에서도 동일한 변화를 나타내었다 이러한 결과 냉동 방법과 기간에 따라 막걸리 내 미생물의 생육을 제어하는 가능성을 알아볼 수 있었다.

Keywords

Acknowledgement

Supported by : 경기도

References

  1. Ahn BH. 1994. Investigation trends in traditional liquor. Bull. Food Tech. 7: 42-47.
  2. Bae SM, Kim HJ, Oh TK, Kho YH. 1990. Preservation of takju by pasteurization. Korean J. Appl. Microbiol. Biotech. 18: 322-325.
  3. Bae SM. 1999. The superiority of Korean traditional wines and their industrial application method. Food Ind. Nutr. 4: 9-12.
  4. Chung DH. 1974. Fermentation and microbial technology. Sunjin Munhwasa. pp. 228-275.
  5. Jeong HK. 1999. A view of Korean alcoholic liquor industry in 21st century. Food Ind. Nutr. 4: 3-8.
  6. Joung EJ, Paek NS, Kim YM. 2004. Studies on Korean takju using the by-product of rice milling. Korean J. Food Nutr. 17: 199-205.
  7. Jung HK, Park ChD, Park HH, Lee GD, Lee IS, Hong JH. 2006. Manufacturing and characteristics of Korean traditional liquor, hahyangju prepared by Saccharomyces cerevisiae HA3 isolated from traditional nuruk. Korean J. Food Sci. Technol. 38: 659-667.
  8. Kang MY, Park YS, Mok CK, Chang HG. 1998. Improvement of shelf-life of Yakju by membrane filtration. Korean J. Food Sci. Technol. 30: 1134-1139.
  9. KFDA. 2003. Code Food, Korea Food and Drug Association. Seoul, Korea.
  10. Kim CJ, Kim DY, Oh MJ, Lee SK, Lee SO, Chung ST, Chung JH. 1990. Fernentation Technology. Sunjinmunwhasa, Seoul, Korea. pp. 79-103.
  11. Kim CJ. 1968. Microbiological and enzymological studieds on takju brewing. J. Korean Agr. Chem. Soc. 10: 69-100.
  12. Kim HY, Lee IS, Kang JY, Kim GY. 2002. Quality characteristics of cookies with various levels of functional rice flour. Korean J. Food Sci. Technol. 34: 642-646.
  13. Jung DS, Kweon MR, Auh JH, Cho KY, Choi YH, Kook SU, Park KH. 1996. Effects of temperature and fluctuation range on microbial growth and quality of foods stored in domestic refrigerator. Korean J. Food Sci. Technol. 28: 632-637.
  14. Kim JY, Sung KW, Bae HW, Yi YH. 2007. pH, acidity, color, reducing sugar, total sugar, alcohol and organoleptic characteristics of puffed rice power added takju during fermentation. Korean J. Food Sci. Technol. 39: 266-271.
  15. Kim KO, Choi HJ. 1995. Optimization of the preparation of ricebased infant foods using freeze drying process. Korean J. Food Sci. Technol. 27: 680-689.
  16. Koh CM, Choi TJ, Lew J. 1973. Microbiological studies on the takju brewing. The Korean local wine. Korean J. Microbiol. 11: 167-174.
  17. Lee CH, Lee HD, Kim KM. 1989. Sensory quality attributes of takju and their changes during pasteurization. Korean J. Diet. Cult. 4: 405-410.
  18. Lee CH, Tae WT, Kim GM, Lee HD. 1991. Studies on the pasteurization conditions of tajku. Korean J. Food Sci. Technol. 23: 44-51.
  19. Lee JH, Lee HD, Kim JY, Kim KM. 1989. Sensory quality attributes of takju and their changes during pasteurization. Korean J. Diet. Cult. 4: 405-410.
  20. Lee SR. 1986. Korean Fermented Foods. Ewha Women's University Press, Seoul, Korea. pp. 222-294.
  21. Lee WY, Rhee CH, Woo CHJ. 2004. Changes of quality characteristics in brewing of chungju (sambaekju) supplemented with dried persimmon and cordyceps sinensis. Korean J. Food Preserv. 11: 240-245.
  22. Miller GL. 1959. Use of dinitrosalicylic acid reagent for determination of reducing sugar. Anal. Chem. 31: 426-428. https://doi.org/10.1021/ac60147a030
  23. Mok CK, Lee JY, Chang HG. 1998. Optimization of heat sterilization condition for Yakju. Food Eng. Prog. 2: 134-143.
  24. National Tax Service Technical Service Institute. 2005. Manufacturing Guideline of Takju and Yakju. National Tax Service Technical Service Institute, Seoul, Korea. pp 31, 53-54, 195-196.
  25. Park YJ, Lee SK, Oh MJ. 1973. Studies on takju yeasts. Park 1. Isolation and identification of takju yeasts. J. Korean Agric. Chem. Soc. 16: 78-84.
  26. SAS Institute. 1988. SAS/STAT User Guide, release 6.30 ed. Washington, D.C, USA.
  27. Shin KR, Kim BC, Yang JY, Kim YD. 1999. Characterization of Yakju prepared with yeasts from fruits. 1. Volatile components in Yakju during fermentation. J. Korean Soc. Food Sci. Nutr. 28: 794-800.
  28. Song JC, Park HJ. 2003. Takju brewing using the uncooked germed brown rice at second stage mash. J. Korean Soc. Food Sci. Nutr. 32: 847-854. https://doi.org/10.3746/jkfn.2003.32.6.847