Food Science of Animal Resources (한국축산식품학회지)

Korean Society for Food Science of Animal Resources (한국축산식품학회)
권호 표지

Studies on the Properties of the Stirred Yogurt Manufactured by Exopolysaccharide Producing Lactic Acid Bacteria

Exopolysaccharide 생성 유산균을 이용한 Stirred Yogurt 특성에 관한 연구

  • Kang Ho-Jin (Institute of Dairy Food Research, Seoul Dairy Co-op.) ;
  • Baick Seung-Chun (Institute of Dairy Food Research, Seoul Dairy Co-op.) ;
  • Yu Je-Hyun (Department of Dairy Science, Konkuk University)
  • Published : 2005.03.01
Download PDF
⟨ Previous Next ⟩

Abstract

We investigated fermentation characteristics and the amount of exopolysaccharide (EPS) produced, and the correlation between EPS and rheological properties in stirred yogurt fermented with Streptococcus thermophilus St-Body 1. The changes of pH and lactic acid concentrations of yogurt showed different patterns according to fermentation temperatures. About 20 to 40% of lactose was utilized during 6 hrs incubation. The higher number of lactic acid bacteria was obtained at 31℃ incubation temperature rather than other incubation temperatures. The higher amount of EPS was produced at 12 hr or 24 hr rather than other incubation period at the same fermentation temperatures. The viscosity continuously increased during the fermentation period, however the syneresis of yogurt was shown the lowest value at 37℃ for 30 hrs incubation. In physical properties, the hardness and adhesiveness increased continuously with decreasing cohesiveness and elasticity as incubation process was extended. The stirred yogurt fermented with S. thermophilus St-Body 1 at 37℃ for 24 hr resulted in the highest score at each sensory evaluation category.

본 연구에서는 EPS 생성 유산균인 S. thermophilus St-Body 1을 발효 온도 및 시간별로 EPS를 분리하여 발효 조건이 EPS 생성에 미치는 영향과 EPS 생성량이 stirred 요구르트의 점도, syneresis, 물성, 관능검사에 미치는 영향에 대하여 조사하였다. pH와 유산 함량 변화는 온도에 따라 다른 경향을 보였으며, 발효 온도가 높을수록 pH 감소가 빠르게 진행되고, 6, 12시간에 많은 유산이 생성되었다. 유당 함량은 발효 6시간 동안에 20∼40%가 이용되었고, 유산균수는 31℃에서 발효한 요구르트가 상대적으로 유산균수가 높은 것으로 나타났다. S. thermophilus St-Body 1은 발효 온도가 낮을수록 더 많은 EPS를 생성하고, 발효 12시간과 24시간에 많은 EPS를 생성하는 것으로 관찰되었다. 점도는 발효 시간이 증가할수록 점도가 증가하였으며, syneresis는 37℃에서 30시간 발효한 stirred 요구르트가 가장 적은 것으로 나타났다. 경도와 접착성은 발효가 진행될수록 증가하는 경향을 보였고, 점착성과 탄력성은 발효가 진행될수록 감소하였다. S. thermophilus St-Body 1로 발효한 요구르트의 관능검사 결과, 37℃, 24시간 발효한 요구르트가 풍미 6.25, 조직 4.25, 외관 3.50으로 가장 높은 수치를 나타내었다.

Keywords

References

  1. AOAC. (1995) Official of analysis. 15th ed. Association of Official Analytical Chemist. Washington. DC
  2. Bouzar, F., Ceming, J., and Desmazeaud, M. (1997) Exopolysaccharide producing and texture promoting abilities of mixed strain starter cultures in yogurt producing. J. Dairy Sci. 80, 2310-2317 https://doi.org/10.3168/jds.S0022-0302(97)76181-2
  3. Degeest, B., Vaningelgem, F., and De Vuyst, L. (2001) Microbial physiology, fermentation kinetics, and process engineering of heteropolysaccharide production by lactic acid bacteria. Int. Dairy J. 11, 747-757 https://doi.org/10.1016/S0958-6946(01)00118-2
  4. Degeest, B., Mozzi, F., and De Vuyst, L. (2002) Effect of medium composition and temperature and pH changes on exopolysaccharide yields and stability during Streptcoccus therrnophilus LY30 fermentation. Int. J. Food Microbiol. 79(3), 161-174 https://doi.org/10.1016/S0168-1605(02)00116-2
  5. De Vuyst, L., Vanderveken, F., Van de Yen, S., and Degeest, B. (1998) Production by and isolation of exopo-lysaccharides from Streptococcus thermophilus grown in a milk medium and evidence for their growth associated biosynthesis. J. Appl. Microbiol. 84(6), 1059-1068 https://doi.org/10.1046/j.1365-2672.1998.00445.x
  6. De Vuyst, L., De Vin, F., Vaningelgem, F., and Degeest, B. (2001) Recent developments in the biosynthesis and applications of heteropolysaccharides from lactic acid bacteria. Int. Dairy J. 11, 687-707 https://doi.org/10.1016/S0958-6946(01)00114-5
  7. Duboc, P. and Mollet, B. (2001) Applications of exopolysaccharides in the dairy industry. Int. Dairy J. 11, 759-768 https://doi.org/10.1016/S0958-6946(01)00119-4
  8. Dubois, M., Gilles, K. A., Hamilton, J. K., Rebers, P. A., and Smith, F. (1956) Calorimetric method for determination of sugars and related substances. Anal. Chem. 28, 350-356 https://doi.org/10.1021/ac60111a017
  9. Dunne, W. M. Jr. (2002) Bacterial adhesion: seen any good biofilms lately? Clin. Microbiol. Rev. 15(2), 155-166 https://doi.org/10.1128/CMR.15.2.155-166.2002
  10. Grobben, G. J., Sikkema, J., Smith, M. R., and de Bont, J. A. M. (1995) Production of extracellular polysaccharides by Lactobacillus delbrueckii ssp. bulgaricus NCFB 2772 grown in a chemically defined medium. J. Appl. Bacteriol. 79, 103-107 https://doi.org/10.1111/j.1365-2672.1995.tb03130.x
  11. Hassan, A. N., Ipsen, R., Janzen, T., and Qvist, K. B. (2003) Microstructure and rheology of yogurt made with cultures differing only in their ability to produce exopolysaccharides. J. Dairy Sci. 86, 1632-1638 https://doi.org/10.3168/jds.S0022-0302(03)73748-5
  12. Hess, S. J., Robets, R. F., and Ziegler, G. R. (1997) Rheological properties of nofat yogurt stabilized using Lactobacillus delbrueckii ssp. bulgaricus producing exopolysaccharide or using commercial stabilizer systems. J. Dairy Sci. 80, 252-263 https://doi.org/10.3168/jds.S0022-0302(97)75933-2
  13. Keogh, M. K. and O'Kennedy, B. T. (1998) Rheology of stirred yogurt as affected by added milks fat, protein and hydrocolloids. J. Food Sci. 63(1), 108-112 https://doi.org/10.1111/j.1365-2621.1998.tb15687.x
  14. Kimmel, S. A., Roberts, R. F., and Ziegler, G. R. (1998) Optimization of exopolysaccharide production by Lactobacillus delbrueckii subsp. bulgaricus RR grown in a semidefmed medium. Appl. Environ. Microbiol. 64, 659-664
  15. Pham, P. L., Dupont, I., Roy, D., Lapointe, G., and Ceming. J. (2000) Production of exopolysaccharide by Lactobacillus rhamnosus R and. analysis of its enzyme degradation during prolonged fermentation. Appl. Environ. Microbiol. 66, 2302-2310 https://doi.org/10.1128/AEM.66.6.2302-2310.2000
  16. Rawson, H. L. and Marshall, V. M. (1997) Effect of 'ropy' strains of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus on rheology of stirred yogurt. Int. J. Food Sci. Tech. 32, 213-220 https://doi.org/10.1046/j.1365-2621.1997.00395.x
  17. Ruas-Madiedo, P., Tuinier, R., Kanning, M., and Zoon, P. (2002) Role of exopolysaccharides produced by Lactococcus lactis subsp. cremoris on the viscosity of fermented milks. Int. Dairy J. 12, 689-695 https://doi.org/10.1016/S0958-6946(01)00161-3
  18. Shin, J. H., Cha, S. C., Lee, J. I., and Yu, J. H. (1995) The effects of whey powder addition on the texture and flavor of frozen yogurt. Kor. J. Food Sci. Ani. Resour. 15, 192- 195
  19. Sutherland, I. W. (1972) Bacterial exopolysaccharide. Adv. Microb. Physiol. 8, 143-212 https://doi.org/10.1016/S0065-2911(08)60190-3
  20. Sutherland, I. W. (2001) Biofilm exopolysaccharides: a strong and sticky framework. Microbiol. 147, 3-9
  21. Zisu, B. and Shah, N. P. (2003). Effects of pH, temperature, supplementation with whey protein concentrate, and adjunct cultures on the production of exopolysaccharides by Streptococcus thermophilus 1275. J. Dairy Sci. 86, 3405- 3415 https://doi.org/10.3168/jds.S0022-0302(03)73944-7
  22. 농림부 (2002) 축산통계자료. 농림부 축산국, 서울, pp. 28