Shelf-life and Quality Characteristics of Tofu Coagulated by Calcium Lactate

젖산칼슘을 응고제로 한 두부의 품질특성과 저장성

  • 이명예 (대구가톨릭대학교 식품산업학부) ;
  • 김순동 (대구가톨릭대학교 식품산업학부)
  • Published : 2004.02.01


To investigate the utilization of calcium lactates (CaL) as coagulants for tofu manufacture, the quality characteristics and shelf-life of tofu made by CaL-P (black snail powder) and CaL-A (black snail ash) were investigated and compared to calcium chloride (CC), magnesium chloride (MC), calcium sulfate (CS ) and standard calcium lactate (CaL-S). And also, total microbe and turbidity of the tofu were determined during storage at 1$0^{\circ}C$. Coagulation ability of CaL-A was the highest, and the ability of CaL-P was higher than that of CaL-S. Yield of CaL-A tofu was similar to those of CS and CC tofu, while the yield of CaL-P tofu was 50% compared to that of CC. L* value of CaL-P tofu was lower, but a* and b* values were higher than those of other tofus. The hardness of tofu showed in the order of CaL-S>CS>CC>CaL-P>MC>CaL-A, while the cohesiveness showed in the order of MC>CaL-S>CC>CS>CaL-P>CaL-A. Calcium contents were 57 mg% in MC tofu, 174 mg% in CS tofu, 116 mg% in CaL-S tofu, 95 mg% in CaL-A tofu and 172 mg% in CaL-P tofu. From the results of microscopic observations, the lower hardness showed the more soft and the smaller particle. The particle of CaL-A tofu was small and uniformity but the size of CaL-P and CC tofu showed coarse. Sensory quality of CaL-P and -A tofu were better than the other tofu evaluated by texture, springiness, flavor and overall taste. The shelf-life estimated by total microbe was 4∼6 days in CC, MC, CS, CaL-S and CaL-A tofu, but 8 days in CaL-P tofu at 1$0^{\circ}C$. From the above results, the CaL-P and -A may believe to use as coagulant for tofu manufacture due to its softened taste and enhanced shelf-life, and higher calcium content which has higher absorbability in human body.


  1. Jung JY, Cho EJ. 2002. The efffect of green tea powder levels on storage characteristics of tofu. Korean J Soc Food Cookery Sci 18: 129-135.
  2. Chun KH, Kim BY, Son T, Hahm YT. 1997. The extension of tofu shelf-life with water-soluble degraded chitosan as immersion solution. Korean J Food Sci Technol 29: 476-481.
  3. Kim JY, Kim JH, Kim JK, Moon KD. 2000. Quality attributed of whole soybean flour tofu affected by coagulant and theirs concentration. Korean J Food Sci Technol 32: 402-409.
  4. Park CK, Hwang IK. 1994. Effects of coagulant concentration and phytic acid addition on the contents of Ca and P and rheological property of soybean curd. Korean J Food Sci Technol 26: 355-358.
  5. Lee SM, Hwang IK. 1997. Texture characteristics of soybeancurds prepared with different coagulants and compositions of soybean-curd whey. Korean J Soc Food Sci 13: 78-85.
  6. Choi YO, Chung HS, Youn KS. 2000. Effects of coagulants on the manufacturing of soybean curd containing natural materials. Korean J Postharvest Sci Technol 7: 249-255.
  7. Martin BR, Weaver CM, Heaney RP, Oackard PT, Smith DL. 2002. Calcium absorption from three salts and $CaSO_4$-fortified bread in premenopausal women. J Agri Food Chem 50: 3874-3876.
  8. Ranhotra GS, Gelroth JA, Leinen SD, Schneller FE. 1997. Bioavailability of calcium in breads fortified with different calcium sources. Cereal Chem 74: 361-363.
  9. Sharma M, Beuchat LR, Doyle MP, Chen J. 2001. Survival of salmonellae in pasteurized, refrigerated calcium fortified orange juice. J Food Prot 64: 1299-304.
  10. Shelef LA. 1994. Antimicrobial effects of lactates: a review. J Food Prot 57: 445-450.
  11. Wang YL, Wu H, Liu YB, Leblanc J. 1998. Newborn bone mineral density and health care during pregnancy. J Bone Mineral Metab 16: 190-192.
  12. Kim KT, Im JS, Kim SS. 1996. A study of the physical and sensory characteristics of ginseng soybean curd prepared with various coagulants. Korean J Food Sci Technol 28: 965-969.
  13. Herbert A, Jeol LS. 1993. Sensory Evaluation Practices. 2nd ed. Academic Press, New York, USA. p 68-94.
  14. Lee YK, Kim SD. 2003. Preparation and characteristics of calcium lactate from black snail. Nutraceuticals & Food 8: 166-172.
  15. Kim DH, Lee KS. 1992. Effects of coagulants on storage of packed tofu. Korean J Food Sci Technol 24: 92-96.
  16. Kim RY, Kim JM, Cho NJ. 1994. Effect of coagulants on the quality of soybean curd added with cow's milk. Agri Chem Biotechnol 37: 370-378.
  17. Lee HJ, Hwang IK. 1994. Textural characteristics and microstructure of soybean curds prepared with different coagulants. Lpream J Soc Food Sci 10: 284-290.
  18. Kim JM, Baek SH, Hwang HS. 1988. Preparation of the tofu coagulant from egg-shell and it's use. J Korean Soc Food Nutr 17: 25-31.
  19. Saio K. 1979. Tofu-relationships between texture and fine structure. Cereal Foods Worlds 24: 342-346.
  20. Kang HY. 1997. Tofu taste and quality as affected by coagulants. Korea Soybean Digest 14: 37-42
  21. Lu JY, Carter E, Chung A. 1980. Use of calcium salts for soybean curd preparation. J Food Sci 45: 32-34.
  22. Moon SJ, Sohn KH, Kim YH. 1979. The study of textural characteristics of soybean curd prepared with various coagulants. Korean Home Economics Association 11-19.
  23. Kim HJ, Kim BY, Kim MH. 1995. Rheological studies of the tofu upon the processing conditions. Korean J Food Sci Technol 27: 324-328.
  24. Mulvihill DM, Kinsella JE. 1987. Gelation characteristics of whey proteins and ${\beta}$-lactoglobulin. Food Tech 41: 102.
  25. Kim DH, Lim MS, Kim YO. 1996. Effect of seaweeds addition on the physicochemical characteristics of soybean curd. J Korean Soc Food Nutr 25: 249-254.
  26. Dotson CR, Frank HA, Cavaletto CG. 1997. Indirect methods as criteria of spoilage in tofu. J Food Sci 42: 273-276.
  27. Takeshi S. 1985. On the slimy spoilage of tofu (soybean curd). Nippon Shokuhin Kogyogakkaishi 32: 1-5.

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