Monitoring of Quality Characteristics of Chungkookjang Products during Storage for Shelf-life Establishment

청국장 제품의 유통기한 설정을 위한 저장중의 품질 특성 monitoring

  • Kim, Dong-Myung (Dodlesem Co. Ltd.) ;
  • Kim, Seong-Ho (Division of Bio-food, Kyungbook Collage of Science) ;
  • Lee, Jin-Man (Division of Bio-food, Kyungbook Collage of Science) ;
  • Kim, Ji-Eun (Division of Food, Biological and Chemical Engineering, Daegu University) ;
  • Kang, Sun-Chul (Division of Food, Biological and Chemical Engineering, Daegu University)
  • 김동명 ((주)도들샘) ;
  • 김성호 (경북과학대학 바이오식품계열) ;
  • 이진만 (경북과학대학 바이오식품계열) ;
  • 김지은 (대구대학교 식품.생명.화학공학부) ;
  • 강선철 (대구대학교 식품.생명.화학공학부)
  • Published : 2005.06.30

Abstract

The major obstacle in the popularization of Chungkookjang is the short shelf-life of $2{\sim}3$ months and some problems concerning storage including the growth of molds even in the products even within shelf-life. To solve these problems we conducted a research to improve its storage by using the vacuumed packaging and sanitary method through seed culture, innoculation and sterilization. For the optimization of storage time, temperature and sterilization temperature, we measured viable cell numbers of bacteria and fungi, amount of gas outbreak and contents of amino type nitrogen and monitored these experimental results by response surface methodology of SAS program, so that we could observe the quality changes of Chungkookjang during shelf-life. Especially fungi, which are the biggest troublemaker in Chungkookjang shelf-life, couldn't be detected from the generally and vacuum-packed samples; also, viable cell numbers were highly influenced by sterilization temperature and in vacuum-packed samples. In the case of vacuum-packed samples, amount of gas outbreak was highly influenced by sterilization temperature of its storage conditions and it was higher in generally packed samples as compared to vacuum-packed samples even at any storage conditions. The changes of pH in generally and vacuum-packed samples were highly influenced by the storage temperature. As the temperatures of storage and sterilization were higher and the storage time was longer, so the amount of gas outbreak was accordingly lower. These results showed that amino type nitrogen contents in generally and vacuum-packed samples were systematically influenced by the temperature, storage time and sterilization temperature. Also the result showed that the change of amino type nitrogen contents during storage was less in vacuum-packed samples than in general ones. Based on the above results, we can produce Chungkookjang products with extended shelf-life of as far as 6 months without any quality change using sanitary manufacturing method, vacuumed packaging condition, sterilization in $70^{\circ}C$ for 60 minutes and storage under $10^{\circ}C$ during shelf-life. According to this research, we have the possibility to greatly increase the goods value of Chungkookjang by developing the manufacture processing and packaging.

References

  1. Cheong, D. H. and Shim S. K. (1994) In Fermented Soy Food. Jisungesaem, Korea, pp. 673-686
  2. Choi, J. S., Kim, J. S., Yoo, S. M., Park, H. J., Kim, T. Y., Chang, C. M. and Shin, S. Y. (1996) Survey on preparation method and consumer response of Chungkookjang. Kor. J. Soybean Res. 13, 29-43
  3. Suh, J. S., Lee, S. G. and Ryu, M. K. (1982) Effect of Bacillus strains on the Chungkookjang processing. Korean J. Food Sci. Technol. 14, 309-314
  4. Son, D. H., Kwon, O. J., Ji, W. D., Choi, U. K., Kwon, O. J., Lee, E. J., Cho, Y. J., Cha, W. S. and Chung, Y. G. (2000) The quality changes of Chungkookjang prepared by Bacillus sp. CS-17 during fermentation time. J. Kor. Soc. Agri. Chem. Biotechnol. 43, 1-6
  5. Kwon, O. J., Kim, J. K., Chung, Y. G. (1986) The characteritics of bacteria isolated form ordinary Korean soy sauce and soybean paste. J. Kor. Soc. Agri. Chem. Biotechnol. 29, 422-428
  6. Cho, D. H. and Lee, W. J (1970) Microbiological studies of Korean native soy-sauce fermentation; A study on the microflora of fermented Korean Maeju loaves. J. Kor. Soc. Agri. Chem. Biotechnol. 13, 35-42
  7. Choi, U. K., Ji, W. D. and Chung Y. G. (1998) Characteristics of Chungkookjang produced by Bacillus subtilis DC-2. J. Kor. Soc. Food Sci. Nutr. 27, 846-851
  8. Lee, Y., L., Kim, S. H., Choung, N. H. and Yim, M. H. (1992) A study on the production of viscous substance during Chungkookjang fermentation. J. Korean Agric. Chem. Soc. 35, 202-209
  9. Floros, J. D. and Chinnan M. S. (1987) Optimization of pimento pepper lye peeling process using response surface methodology. Trans. ASEA 30, 560-566
  10. SAS (1990) SAS/STAT User's Guide, Version 6.0, (4th. ed.), Vol. 2, SAS Institute Inc. pp. 1-1457
  11. Martha, L. A. and James, P. B. (1992) The Mathematica Handbook Compatible with Mathematica, Version 2.0, An Inprint of a Division of Academic Press Inc. Harcourt Brace & Co. Massachussetts, pp. 15-511
  12. Choi, K. H. and Cho, M. Y. (1997) Thermal sterilizing characteristics of Bacillus subtilis spores contained in Chungkookjang. Archives of Taegu Hyosung Catholic Univ. pp. 191-198
  13. Kim, D. H., Yook, H. S. Youn, K. C., Cha, B. S., Kim, J. O. and Byun, M. W. (2000) Changes of microbiological and general quality characteristics of gamma irradiated Chungkookjang. Korean J. Food Sci. Technol. 32, 896-901
  14. Choi, S. H. and Ji, Y. A. (1989) Changes in flavor of Chungkookjang during fermentation. Korean J. Food Sci Technol. 21, 229-234