Isoelectric focusing and ELISA for detecting adulteration of donkey milk with cow milk.

Donkey milk has been recently revalued intensely due to its nutritional properties. Moreover, donkey milk has been proposed as an effective alternative food for some infants with cow milk allergy. Two fast analytical methods were proposed to detect the fraudulent practice of blending cow milk to donkey milk.

Occurrence of major whey proteins in the pH 4.6 insoluble protein fraction from UHT-treated milk.

A clear picture of the protein rearrangement in milk following UHT-treatment was drawn by a comparative analysis of the pH 4.6 soluble protein fraction (SPF) and the pH 4.6 insoluble protein fraction (IPF) recovered from raw and UHT-treated milk samples.

Fast isoelectric focusing and antipeptide antibodies for detecting bovine casein in adulterated water buffalo milk and derived mozzarella cheese.

Plasmin hydrolysis of water buffalo casein (CN) can liberate a peptide comigrating with bovine gamma(2)-CN. Occurrence of this peptide may lead to false-positive detection of cow's milk for a genuine water buffalo cheese when it is analyzed by applying a fast version of the European official method for detecting bovine casein in water buffalo cheese. After isoelectric focusing of CN plasminolysates, performed according to the official method, immunoblot analysis with antipeptide antibodies was assayed to distinguish between gamma(2)-CN and the interfering bovine gamma(2)-CN-like peptide.

Detection of pH 4.6 insoluble beta-lactoglobulin in heat-treated milk and Mozzarella cheese.

Different protein aggregates including beta-lactoglobulin (beta lg) were detected in the pH 4.6 insoluble fraction recovered from actual heat-treated milk samples by gel electrophoresis and immunoblotting. A competitive enzyme-linked immunosorbent assay (ELISA) using anti-beta lg polyclonal antibodies was developed to analyze the beta lg partition in the protein fractions obtained upon acidification of both milk and Mozzarella cheese at pH 4.

Coupling immunomagnetic separation on magnetic beads with matrix-assisted laser desorption ionization-time of flight mass spectrometry for detection of staphylococcal enterotoxin B.

The growing importance of mass spectrometry for the identification and characterization of bacterial protein toxins is a consequence of the improved sensitivity and specificity of mass spectrometry-based techniques, especially when these techniques are combined with affinity methods. Here we describe a novel method based on the use of immunoaffinity capture and matrix-assisted laser desorption ionization-time of flight mass spectrometry for selective purification and detection of staphylococcal enterotoxin B (SEB). SEB is a potent bacterial protein toxin responsible for food poisoning, as well as a potential biological warfare agent.