Health  Vol.1 No.3 , November 2009
2DGE-coomassie brilliant blue staining used to differentiate pasteurized milk from reconstituted milk
ABSTRACT
Differentiating pasteurized milk and reconsti-tuted milk by scientific approach was necessary to defend consumer from economic fraud of wrong labeling. In this paper 2DGE (2 Dimen-sional Gel Electrophoresis)-coomassie brilliant blue staining method was employed and sig-nificant color intensity changing was observed among raw milk, pasteurized milk, UHT milk and reconstituted milk. For example, the intensity of 10 protein spots including casein and lac-toglobulin reduced more than two folds from pasteurized milk to reconstituted milk. However, DIGE (Differential Gel Electrophoresis) assay showed that the majority protein remained simi-lar level from pasteurized milk to reconstituted milk. Therefore the color fading of coomassie brilliant blue stained 2D gels may be due to other biochemical reaction, such as Maillard reaction, instead of protein degradation. Stability of 2DGE pattern was confirmed by running six gels of the same sample in parallel and software analysis showed that all proteins were at similar level. Two commercialized pasteurized milk samples and one reconstituted milk sample were tested by 2DGE-coomassie blue staining method and re-constituted milk could be easily identified.

Cite this paper
nullWu, Y. , Chen, Y. , Wang, B. , Wang, H. , Yuan, F. and Zhao, G. (2009) 2DGE-coomassie brilliant blue staining used to differentiate pasteurized milk from reconstituted milk. Health, 1, 146-151. doi: 10.4236/health.2009.13024.
References
[1]   A. Fagerberg, (2008) Field study on milk quality in China, Internatinal Dairy Topics, 7(1), 11-12.

[2]   J. D. Block, M. Merchiers, L. Mortier, A. Braekman, W. Ooghe, R. V. Renterghem, (2003) Monitoring nutritional quality of milk powders: capillary electrophoresis of the whey protein fraction compared with other methods, In-ternational Dairy Journal, 13, 87-94.

[3]   G. X. Liu, (2003) Reconstituted milk≠Pure fresh milk, City Quality Supervision, 4, 46.

[4]   M. Lacroix, J. Leonil, C. Bos, G. Henry, G. Airinei, J. Fau- quant, D. Tome, C. Gaudichon, (2006) Heat markers and quality indexes of industrially heat-treated [15N] milk protein measured in rats, J. Agric. Food Chem., 54, 1508-1517.

[5]   F. Guyomarch, F. Warin, D. Muir, J. Leave, (2000) Lac-tosylation of milk proteins during the manufacture and storage of skim milk powders, International Dairy Journal, 10, 863-872.

[6]   M. Carbonaro, (2004) Proteomics: present and future in food quality evaluation, Trends in Food Science & Technology, 15, 209-216.

[7]   M. A. Manso, J. Leonil, G. Jan, V. Gagnaire, (2005) Ap-plication of proteomics to the characterization of milk and dairy products, International Dairy Journal, 15, 845-855.

[8]   R. O. Donnella, J. W. Hollanda, H. C. Deethb, P. Alewo- oda, (2004) Milk proteomics, International Dairy Journal, 14, 1013-1023.

[9]   G. Miranda, F. M. Mahé, C. Leroux, P. Martin, (2004) Proteomic tools to characterize the protein fraction of Equidae milk, Proteomics, 4, 2496-2509.

[10]   S. Kuy, V. C. Kelly, A. M. Smit, D. J. Palmer, G. J. Coo-per, (2007) Proteomic analysis of whey and casein pro-teins in early milk from the marsupial Trichosurus vulpecula, the common brushtail possum, Comparative Biochemistry and Physiology, 2, 112-120.

[11]   J. Joss, M. Molloy, L. Hinds, E. Deane, (2007) Proteomic analysis of early lactation milk of the tammar wallaby (Macropus eugenii), Comparative Biochemistry and Physiology, 2, 150-164.

[12]   J. W. Holland, H. C. Deeth, P. F. Alewood, (2004) Pro-teomic analysis of k-casein micro-heterogeneity, Pro-teomics, 4, 743-752.

[13]   C. J. Hogarth, J. L. Fitzpatrick, A. M. Nolan, F. J. Young, A. Pitt, P. D. Eckersall, (2004) Differential protein com-position of bovine whey: A comparison of whey from healthy animals and from those with clinical mastitis, Proteomics, 4, 2094-2100.

[14]   P. Resmini, L. Pellegrino, F. Masott, A. Tirelli, F. Prati, (1992) Detection of reconstituted milk powder in raw and in pasteurized milk by HPLC of furosine, Scienzae Tec-nica Lattiero Casearia, 3(3), 169-186.

[15]   K. McDonald, (2009) Overcoming the Coomassie blues. Drug Discovery & Development. http://www.dddmag.com/Article-Overcoming the Coomas-Sie Blues-060409.aspx

[16]   S. M. Rutherfurd, P. J. Moughan, (1997) Application of a new method for determining digestible reactive lysine to variably heated protein sources, J. Agric. Food Chem., 45(5), 1582-1586.

 
 
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