Electrophoretic and chromatographic techniques were used to determine water-soluble peptide profiles aiming to identify the adulteration of buffalo milk mozzarella cheese by the addition of cow's milk. Thus, cheeses were produced with contents of cow's milk varying from 0% to 100%, and the peptides extracted after production and after 20 days of refrigeration. Polyacrylamide gel electrophoresis under denaturing conditions in the presence of sodium dodecyl sulphate (SDS-PAGE) identified a potential peptide marker of exclusively bovine origin with a size of about 21 kDa for the addition of cow's milk above 30%. Reverse-phase high-performance liquid chromatography (RP-HPLC) indicated the existence of two potential peptides present in higher concentrations in buffalo milk and one exclusive for cow's milk, the latter making it possible to estimate the addition of cow's milk to buffalo milk. Six commercial brands of buffalo mozzarella cheese were evaluated, and indications of adulteration found in four of them.
Electrophoresis and chromatography were used to detect fraud in buffalo mozzarella cheese. A bovine marker peptide (21 kDa) was identified in the SDS-PAGE analyses. One peak (tR = 33.6 minutes) identified by RP-HPLC, presented a satisfactory correlation, with the peak area increasing with increase in the proportion of cow's milk. Fraud was suspected in four of the six comercial brands of buffalo mozzarella cheese evaluated.