A Control Method To Inspect the Compositional Authenticity of Minas Frescal Cheese by Gel Electrophoresis

作者：Magenis Renata B; Prudencio Elane S; Molognoni Luciano; Daguer Heitor^*

来源：Journal of Agricultural and Food Chemistry, 2014, 62(33): 8333-8339.

DOI：10.1021/jf502864e

• SDS-PAGE
• white cheeses
• adulterations
• dairy inspection
• whey

This study introduces a qualitative method to inspect the compositional authenticity of white nonripened cheeses like Minas Frescal, a typical Brazilian cheese, especially when irregular replacement of milk by whey is suspected. A sodium dodecyl sulfate gel electrophoresis (SDS-PAGE) method, followed by image densitometry, was validated. Cheeses were freeze-dried to electrophoresis, and beta-lactoglobulin (beta-LG) was chosen as the adulteration marker. In gel trypsin digestion followed by matrix assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry provided its identification. Cheeses with a minimum of 14 mg.g(-1) of beta-LG are considered to be adulterated. The method shows satisfactory precision with a detection limit of 7 mg.g(-1). Forty-two commercial samples from inspected establishments were then assessed and subjected to cluster analysis. Compliant and noncompliant groups were set with 24 (57%) authentic samples and 18 (43%) adulterated samples, respectively, showing that proper analytical monitoring is required to inhibit this practice.

• 出版日期2014-8-20