Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, via Orabona 4, 70126, Bari, Italy.
J Mass Spectrom. 2012 Sep;47(9):1141-9. doi: 10.1002/jms.2995.
In dairy field, one of the most common frauds is the adulteration of higher value types of milk (sheep's and goat's) with milk of lower value (cow's milk). This illegal practice has an economic advantage for milk producers and poses a threat for consumers' health because of the presence of hidden allergens as, for example, cow milk proteins, in particular, α(s1)-casein and β-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/ionization-time-of-flight (MALDI-TOF) 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' and goats', cows' and sheep's and goats' and sheep's milk (concentrations of each milk varied from 0% to 100%) were prepared, and tryptic digests were analyzed by MALDI-TOF MS. The use of the new MALDI matrix α-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.
在乳品行业，最常见的欺诈之一是将高价值类型的牛奶（绵羊和山羊）与低价值的牛奶（牛奶）混合。这种非法做法对牛奶生产商具有经济优势，但由于存在隐藏的过敏原，例如牛奶蛋白，特别是α(s1)-酪蛋白和β-乳球蛋白，对消费者的健康构成威胁。对检测这种欺诈的敏感技术的迫切需求促使开发了色谱、免疫酶、电泳和质谱分析。在当前的工作中，我们提出了一种快速、可重复和敏感的方法，该方法基于牛奶胰蛋白酶消化物的直接基质辅助激光解吸/电离-飞行时间 (MALDI-TOF) MS 分析，通过评估肽谱中的种特异性标记物来检测牛奶掺假。制备了几种纯生和商业牛奶样品以及含有牛奶、山羊奶、牛奶和绵羊奶以及绵羊奶的二元混合物（每种牛奶的浓度从 0%到 100%不等），并通过 MALDI-TOF MS 对胰蛋白酶消化物进行了分析。使用新的 MALDI 基质α-氰基-4-氯肉桂酸可检测到 5%掺假水平的牛奶和山羊奶肽标记物。最后，根据初步数据，该策略似乎也可成功应用于检测奶酪样品中的类似掺假。
