Applied Biological Chemistry

The Korean Society for Applied Biological Chemistry (한국응용생명화학회)
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Use of Freshness Indicator for Determination of Freshness and Quality Change of Tofu During Storage

신선도표시계를 이용한 두부의 저장 중 신선도 측정 및 품질 변화

  • Shin, Hee-Young (Department of Food Science & Technology, College of Agriculture & Life Sciences, Chungnam National University) ;
  • Ku, Kyoung-Ju (Department of Food Science & Technology, College of Agriculture & Life Sciences, Chungnam National University) ;
  • Park, Sang-Kyu (Gwangju Institute of Science and Technology) ;
  • Song, Kyung-Bin (Department of Food Science & Technology, College of Agriculture & Life Sciences, Chungnam National University)
  • Published : 2006.06.01
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Abstract

To determine freshness and quality change of tofu during storage, we manufactured a freshness indicator and monitored the surface pH, volatile basic nitrogen (VBN), thiobarbituric acid reacted substance (TBARS), total bacterial counts, and sensory evaluation. Tofu had a change in color of the freshness indicator after storage of 8 days at $4^{\circ}C$, and its pH and total bacterial counts reached 5.6 and 7.63 log CFU/g, respectively. VBN and TBARS values increased and reached the decay point at the time of color change of the freshness indicator. Sensory evaluation also indicated that samples were unacceptable by off-odor and decrease of firmness at day 8 of storage. These results suggest that a freshness indicator should be useful in determining expiration date of tofu products during marketing by indicating the microbial safety as well as sensory change.

두부의 저장 중 신선도를 판정 할 수 있는 신선도표시계를 제작하여 두부의 표면에 부착하여 품질변화를 측정하였다. 부패시점을 판정하기 위하여 pH, VBN, TBARS, 총균수 및 관능검사를 수행하였다. 두부의 저장 중 품질변화를 측정한 결과 신선도표시계의 반응 시점과 같은 저장 8일째에 두부는 부패초기수준에 도달하여 pH는 5.6, 총균수는 7.63 log CFU/g의 값을 나타내었다. 또한 VBN, TBARS 값도 상승하였고, 관능검사 결과도 저장 8일 이후에는 이취 및 표면에 점질물 생성 및 조직의 저하 등 가식이 불가능 하였다. 따라서 본 연구에서 사용된 신선도표시계는 두부의 저장 중 신선도를 실시간으로 나타내줌으로써 두부의 유통기한 확립 측면에서 매우 유용한 도구가 될 것으로 판단된다.

Keywords

References

  1. Jung, J. Y. and Cho, E. J. (2002) The effect of green tea powder levels on storage characteristics of tofu. Korean J. Soc. Food Cookery Sci. 18, 129-135
  2. Jung, G. T., Ju, I. O., Choi, J. S. and Hong, J. S. (2000) Preparation and shelf of soybean curd coagulated by fruit juice Schizandra chinensis ruprecht (omija) and Prunu mume (maesil). Korean J. Food Sci. Technol. 32, 1087-1092
  3. Kang, S. H., Lee, Y. W. and Dh, W. T. (1998) A study on characteristics of spoilage bacteria isolated from packed tofu. J. Fd. Hyg. Safety. 13, 383-387
  4. Kwon, H. R. and Choi, K. H. (1999) Changes in physico and biochemical quality of packed tofu during cold storage. Daegu Hyosung Catholic Univ. Appl Sci. 7, 73-79
  5. Cho, S. I., Kim, Y. Y., Park, T. S. and Hwang, K. Y. (2004) Development of beef freshness sensor using NIR spectroscopy. J. Biosys. Eng. 29, 539-543 https://doi.org/10.5307/JBE.2004.29.6.539
  6. Yamamoto, M. and Sonehara, M. (1953) An assay method for freshness of fishes by the estimation of pH value. Bull. Japan Soc. Sci. Fish 9, 761-76
  7. Kim, N. S. (2004) Biosensors for food quality and contaminate detection. J. Food Sci. Ind. 37, 4-10
  8. Kim, J. H., Rhie, D. H., Kim, T. J. and Noh B. S. (1998) Development of biosensor for simultaneous determination of glucose lactic acid and ethanol. Korean J. Food Sci. Technol. 30, 22-34
  9. Park, I. S., Kim, J. H., Kim, T. J., Kim, N. S. and Noh, B. S. (1996) Simultaneous determination of glucose and ethanol of takju by biosensor using dual cathode electrode. Korean J. Food Sci. Technol. 28, 974-980
  10. Kim, H. K. and Noh, B. S. (2002) Optimization of Sikhe processing using the obtained data by biosensor. Korean J.Food Sci. Technol. 34, 65-72
  11. Ihn, G. S., Kim, I. T. and Sohn, M. J. (1990) The development of yeast biosensor for the determination of sucrose. Anal. Sci.Technol. 3, 67-72
  12. Kwon, H. S., Kim, K. K. and Lee, C. G. (1996) Cabbage root tissue based amperometric biosensor for determination of hydrogen peroxide. J. Korean Chem. Soc. 40, 278-282
  13. Park, S. K. (2003) A freshness indicator of foodstuffs. Korean Patent. 0038202
  14. Korea Food and Drug Administration. (2002) In Food code. South Korea. pp. 222-223
  15. Ahn, D. U., Olsin, D. G., Jo, C., Chen, X., Wu, C. and Lee, J. I. (1998) Effect of muscle type, packaging, and irradiation on lipid oxidation, volatile production, color in raw pork patties. Meat Sci. 49, 27-39 https://doi.org/10.1016/S0309-1740(97)00101-0
  16. Zhu, M. J., Mendonca, A. and Ahn, D. U. (2004) Temperature abuse affects the quality of irradiation pork loin. Meat Sci. 67, 673-649
  17. APHA. (1995) In Standard methods for the examination of water and wastewater. 19th ed. Method 4-54. American Public Health Association, Washington DC
  18. SAS (2001) In SAS User's Guide. Statistical Analysis Systems Institute Inc., Cary, NC
  19. Lee, Y. B., Kim, T. S. and Yeo, I. H. (1995) Study on the change of quality index of packed tofu. Korean Soybean Digest. 12, 56-60
  20. Lee, K. S., Kim, D. H., Baek, S. H. and Choun, S. H. (1990) Effects of coagulants and soaking solutions of tofu (soybean curd) on extending its shelf life. Korean J. Food Sci. Technol. 22, 116-122
  21. Kim, D. W. and Lee, K. S. (1992) Effects of coagulants on storage of packed tofu. Korean J. Food Sci. Technol. 24, 92-96
  22. Lee, S. K. and Kim, C. S. (1992) Effects of heat treatment on storage of packaged tofu. J. Korean Agric. Chem. Soc. 35, 490-494
  23. Shirakawa, T. (1985) On the slimy spoilage of tofu (soybean curd). Nippon Shokuhin Kogyo Gakkashi 32, 1-5 https://doi.org/10.3136/nskkk1962.32.1
  24. Brewer, M. S., Ikins, W. G and Harbers C. A. (1992) TBA values, sensory characteristics and volatiles in ground pork during long-term frozen storage: Effects of packaging. J. Food Sci. 57, 558-563 https://doi.org/10.1111/j.1365-2621.1992.tb08042.x
  25. Jeong, R. J., Jong, Y. K., Kyung, M. I. and Cho, D. H. (2005) Anti-obese effects of mixture contained pin needle, black tea and green tea extracts. J Korean Soc. Appl. Biol. Chem. 48, 375-381
  26. Kim, J. and Jeon, J. R. (2005) Quality characteristics of tofu added with black soybean hull powder. Korean J. Food Culture 20, 633-637
  27. Dotson, C. R., Frank, H. A. and Cavaletto, C. G. (1997) Indirect methods as criteria of spoilage in tofu. J. Food Sci. 42, 273-276 https://doi.org/10.1111/j.1365-2621.1977.tb01270.x
  28. Jang, W. Y., Kim, B. Y. and Shin, D. H. (1995) Studies on the physical properties of soybean curd stored in the solution of different salt concentration. Agric. Chem. Biotechnol. 38, 135-140
  29. Park, I. K., Kim, S. Y. and Kim, S. D. (1994) Storage of soybean curd prepared with ozone treated soybean. J. East Asian Soc. Dietary Life 4, 69-74