Journal of thermal analysis

, Volume 49, Issue 2, pp 857–862 | Cite as

Comparative studies on some analytical methods

Thermal decomposition of powder milk
  • R. O. Macêdo
  • O. M. de Moura
  • A. G. de Souza
  • A. M. C. Macêdo
Biological/Life Sciences


This work present comparative results on powder milk storage quality, obtained from analytical methods. Protein content was determined conventional (Kjeldahl) and colorimetric with biuret reagent at 540 nm and integral quality by thermogravimetric and biological methods. A method was developed for the protein separation of powder milk. Powder milk was submitted to degradation processes at 45, 60 and 80°C for 20 days. The results indicated that protein content values were inconsistent if determinations by Kjeldahl and colorimetric methods and biological tests were compared. There is evidence of thermal decomposition of powder milk as detected by biological and thermogravimetric methods.


analytical methods kinetics powder milk temperature 


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  1. 1.
    W. Huss, Landwirtsch. Forsch., 27 (1974) 199.Google Scholar
  2. 2.
    P. A. Finot, Kieler Milch Wirtschaftliche Forschungsberichte, 35 (1983) 357.Google Scholar
  3. 3.
    M. Okamoto and R. Hayashi, Agric. and Biol. Chem., 49 (1985) 1683.Google Scholar
  4. 4.
    A. G. Gornall, C. J. Bardawill and M. M. David, J. Biol. Chem., 177 (1949) 751.Google Scholar
  5. 5.
    Institute Adolfo Lutz, Normas Analíticas do Institute Adolfo Lutz, IAL, São Paulo 1985.Google Scholar
  6. 6.
    Escola Paulista de Medicina, Manual para Técnicos de Biotério, Finep, Rio de Janeiro 1990.Google Scholar
  7. 7.
    R. D. Phillips and J. W. Finley, Protein Quality and the Effects of Processing, Marcel Dekker, N. Y. 1989.Google Scholar
  8. 8.
    G. Barone, C. Giancola and A. Verdoliva, Thermochim. Acta, 199 (1992) 197.CrossRefGoogle Scholar
  9. 9.
    J. Mauron, Prog. Food Nutr. Sci., 5 (1981) 136.Google Scholar
  10. 10.
    J. A. Farfan, Química de Proteínas, UNICAMP, Campinas-SP, 1990, p. 134.Google Scholar

Copyright information

© Akadémiai Kiadó 1997

Authors and Affiliations

  • R. O. Macêdo
    • 1
  • O. M. de Moura
    • 1
  • A. G. de Souza
    • 1
  • A. M. C. Macêdo
    • 1
  1. 1.Departamento de Química/CCEN/UFPBJoão Pessoa, ParaíbaBrazil

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