Advertisement

Food Biophysics

, Volume 6, Issue 1, pp 77–83 | Cite as

Heat-Induced Whey Protein Gels: Effects of pH and the Addition of Sodium Caseinate

  • Carolina S. F. Picone
  • Katiuchia P. Takeuchi
  • Rosiane L. CunhaEmail author
ORIGINAL ARTICLE

Abstract

The effects of pH (6.7 or 5.8), protein concentration and the heat treatment conditions (70 or 90 °C) on the physical properties of heat-induced milk protein gels were studied using uniaxial compression, scanning electron microscopy, differential scanning calorimetry, and water-holding capacity measurements. The systems were formed from whey protein isolate (10–15% w/v) with (5% w/v) or without the addition of caseinate. The reduction in pH from 6.7 to 5.8 increased the denaturation temperature of the whey proteins, which directly affected the gel structure and mechanical properties. Due to this increase in the denaturation temperature of the β-lactoglobulin and α-lactalbumin, a heat treatment of 70 °C/30 min did not provide sufficient protein unfolding to form self-supporting gels. However, the presence of 5% (w/v) sodium caseinate decreased the whey protein thermo stability and was essential for the formation of self-supporting gels at pH 6.7 with heat treatment at 70 °C/30 min. The gels formed at pH 6.7 showed a fine-stranded structure, with great rigidity and deformability as compared to those formed at pH 5.8. The latter had a particulate structure and exuded water, which did not occur with the gels formed at pH 6.7. The addition of sodium caseinate led to less porous networks with increased gel deformability and strength but decreased water exudation. The same tendencies were observed with increasing whey protein concentration.

Keywords

Whey protein Sodium caseinate Microstructure Mechanical properties pH Protein denaturation 

Notes

Acknowledgments

This work was supported by the Fundação de Amparo à Pesquisa e Desenvolvimento de São Paulo (FAPESP—Brazil; Grant No. 2003/08119-5), and the Brazilian National Research Council (CNPq, Brazil).

References

  1. 1.
    S.P.F.M. Roefs, K.G. de Kruif, Eur. J. Biochem. 226, 883–889 (1994)CrossRefGoogle Scholar
  2. 2.
    J.M. Aguilera, Food Technol. 49, 83–89 (1995)Google Scholar
  3. 3.
    G.R. Ziegler, E.A. Foegeding, Adv. Food Nutr. Res. 34, 203–298 (1990)CrossRefGoogle Scholar
  4. 4.
    S. Ikeda, V.J. Morris, Biomacromolecules 3, 382–389 (2002)CrossRefGoogle Scholar
  5. 5.
    M. Stading, A.M. Hermansson, Food Hydrocoll. 5, 339–352 (1991)CrossRefGoogle Scholar
  6. 6.
    S. Ikeda, E.A. Foegeding, T. Hagiwara, Langmuir 15, 8584–8589 (1999)CrossRefGoogle Scholar
  7. 7.
    W. Sittikijyothin, P. Sampaio, M.P. Gonçalves, Food Hydrocoll. 21, 1046–1055 (2007)CrossRefGoogle Scholar
  8. 8.
    E. Ibanoglu, Food Chem. 90, 621–626 (2005)CrossRefGoogle Scholar
  9. 9.
    R.I. Baeza, A.M.R. Pilosof, Food Sci. Technol. 35, 393–399 (2002)Google Scholar
  10. 10.
    M. Paulsson, P. Dejmek, J. Dairy Sci. 73, 590–600 (1990)CrossRefGoogle Scholar
  11. 11.
    J.C. Montejano, D.D. Hamann, T.C. Lanier, J. Texture Stud. 16, 403–424 (1985)CrossRefGoogle Scholar
  12. 12.
    E.A. Foegeding, Food Biophys. 1, 41–50 (2006)CrossRefGoogle Scholar
  13. 13.
    AOAC, Official Methods of Analysis, 14th edn. (Association of Official Analytical Chemists, Washington, 1985)Google Scholar
  14. 14.
    J.F. Steffe, Rheological methods in food process engineering (Freeman, East Lansing, 1996)Google Scholar
  15. 15.
    P. Schkoda, A. Hechler, H.G. Kessler, Int. Dairy J. 9, 269–273 (1999)CrossRefGoogle Scholar
  16. 16.
    J.I. Boye, I. Alli, Food Res. Int. 33, 673–682 (2000)CrossRefGoogle Scholar
  17. 17.
    D. Christ, K.P. Takeuchi, R.L. Cunha, J. Food Sci. 70, E230–E238 (2005)CrossRefGoogle Scholar
  18. 18.
    D.M. Mulvihill, M. Donovan, Ir. J. Food Sci. Technol. 11, 43–75 (1987)Google Scholar
  19. 19.
    P. Relkin, D.M. Mulvihill, Crit. Rev. Food Sci. Nutr. 36, 565–601 (1996)CrossRefGoogle Scholar
  20. 20.
    E.H.C. Bromley, M.R.H. Krebs, A.M. Donald, Eur. Phys. J. E Soft Matter 21, 145–152 (2006)CrossRefGoogle Scholar
  21. 21.
    M. Stading, M. Langton, A.-M. Hermansson, Food Hydrocoll. 7, 195–212 (1993)CrossRefGoogle Scholar
  22. 22.
    S. Varunsatian, K. Watanabe, S. Hayakawa, R. Nakamura, J. Food Sci. 48, 42–70 (1983)CrossRefGoogle Scholar
  23. 23.
    I.J. Haug, H.M. Skar, G.E. Vegarud, T. Langsrud, K.I. Draget, Food Hydrocoll. 23, 2287–2293 (2009)CrossRefGoogle Scholar
  24. 24.
    N.K.D. Kella, J.E. Kinsella, Biochem. J. 255, 113–118 (1988)Google Scholar
  25. 25.
    M. Langton, A.-M. Hermansson, Food Hydrocoll. 7, 11–12 (1993)CrossRefGoogle Scholar
  26. 26.
    M. Langton, A.-M. Hermansson, Food Hydrocoll. 7, 195–212 (1993)CrossRefGoogle Scholar
  27. 27.
    C. Öhgren, M. Langton, A.-M. Hermansson, J. Mater. Sci. 39, 6473–6482 (2004)CrossRefGoogle Scholar
  28. 28.
    T. Lefèvre, M. Subirade, Biopolymers 54, 578–586 (2000)CrossRefGoogle Scholar
  29. 29.
    M. Verheul, S.P.F.M. Roefs, Food Hydrocoll. 12, 17–24 (1998)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Carolina S. F. Picone
    • 1
  • Katiuchia P. Takeuchi
    • 2
  • Rosiane L. Cunha
    • 1
    Email author
  1. 1.Department of Food Engineering, Faculty of Food EngineeringUniversity of Campinas (UNICAMP)CampinasBrazil
  2. 2.Department of Food Technology, School of AgronomyUniversity of GoiásGoianiaBrazil

Personalised recommendations