Linearization of the Bradford protein assay to application in cow milk proteins quantification by UV-Vis spectrophotometry method

Authors

  • Alessa Siqueira de Oliveira dos Santos Universidade Federal de Juiz de Fora
  • Fabiano Freire Costa Universidade Federal de Juiz de Fora
  • Wesley Tinoco Esteves Universidade Federal de Juiz de Fora
  • Maria Aparecida Vasconcelos Brito Embrapa Gado de Leite
  • Marco Antônio Moreira Furtado Universidade Federal de Juiz de Fora
  • Marta Fonseca Martins Embrapa Gado de leite

DOI:

https://doi.org/10.14295/2238-6416.v69i6.350

Keywords:

bovine, skimmed milk, spectrophotometry, proteins quantification, β-casein, BSA.

Abstract

Reliable methods for determination and quantification of total protein in food are essential information to ensure quality and safety of food trade. The objective of this study was to evaluate the linearity of calibration curves obtained from different proteins (blood serum albumin-BSA, α-LA, β-LG, αs, β and κ-CAS) with the reagent of Bradford. Comercial UHT skimmed bovine milk was analyzed for the determination of total protein using the Bradford method by reading at 595 nm. The determination of the concentrations of total milk protein was achieved by linear regression. The Bradford method showed a high sensitivity for the determination of total proteins in bovine milk dilution 1:25 to values closer to those obtained by the Kjeldahl method. The results showed that the calibration curve of standard proteins β-CN and BSA obtained better linearity with less variation in the absorbance measurements for the determination of total protein of milk.

Author Biographies

  • Alessa Siqueira de Oliveira dos Santos, Universidade Federal de Juiz de Fora
    Departamento de Farmácia; Qualidade do Leite e Derivados
  • Fabiano Freire Costa, Universidade Federal de Juiz de Fora
    Departamento de Farmácia; Qualidade do leite e derivados
  • Wesley Tinoco Esteves, Universidade Federal de Juiz de Fora
    Departamento de Química
  • Maria Aparecida Vasconcelos Brito, Embrapa Gado de Leite
    Laboratório de Microbiologia do Leite; Qualidade Microbiológica do Leite
  • Marco Antônio Moreira Furtado, Universidade Federal de Juiz de Fora
    Departamento de Farmácia; Qualidade do leite e derivados
  • Marta Fonseca Martins, Embrapa Gado de leite
    Laboratório de Genética Molecular; Genética

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Published

2014-10-28

Issue

Section

Artigos/Articles

How to Cite

Santos, A. S. de O. dos, Costa, F. F., Esteves, W. T., Brito, M. A. V., Furtado, M. A. M., & Martins, M. F. (2014). Linearization of the Bradford protein assay to application in cow milk proteins quantification by UV-Vis spectrophotometry method. Journal of Candido Tostes Dairy Institute, 69(6), 415-423. https://doi.org/10.14295/2238-6416.v69i6.350