Detection of sheep and goat milk adulterations by direct MALDI-TOF MS analysis of milk tryptic digests

作者：Calvano Cosima Damiana^*; De Ceglie Cristina; Monopoli Antonio; Zambonin Carlo Giorgio

来源：Journal of Mass Spectrometry, 2012, 47(9): 1141-1149.

DOI：10.1002/jms.2995

• milk adulteration
• goat
• cow
• sheep
• MALDI
• peptide

In dairy field, one of the most common frauds is the adulteration of higher value types of milk (sheep%26apos;s and goat%26apos;s) with milk of lower value (cow%26apos;s milk). This illegal practice has an economic advantage for milk producers and poses a threat for consumers%26apos; health because of the presence of hidden allergens as, for example, cow milk proteins, in particular, alpha s1-casein and beta-lactoglobulin. The urgent need of sensitive techniques to detect this kind of fraud brought to the development of chromatographic, immunoenzymatic, electrophoretic and mass spectrometric assays. In the current work, we present a fast, reproducible and sensitive method based on the direct matrix-assisted laser desorption/ionizationtime-of-flight (MALDITOF) MS analysis of milk tryptic digests for the detection of milk adulteration by evaluating specie-specific markers in the peptide profiles. Several pure raw and commercial milk samples and binary mixtures containing cows%26apos; and goats%26apos;, cows%26apos; and sheep%26apos;s and goats%26apos; and sheep%26apos;s milk (concentrations of each milk varied from 0% to 100%) were prepared, and tryptic digests were analyzed by MALDITOF MS. The use of the new MALDI matrix alpha-cyano-4-chlorocinnamic acid allowed to detect cow and goat milk peptide markers up to 5% level of adulteration. Finally, from preliminary data, it seems that the strategy could be successfully applied also to detect similar adulterations in cheese samples.

• 出版日期2012-9