Identification of adulteration in milk by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

The development is described of a rapid, simply and accurate analytical method aimed at evaluating both the presence of cow milk in either raw ewe and water buffalo milk samples employed in industrial processes and the addition of powdered milk to samples of fresh raw milk, using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). The presence of adulteration is defined by evaluating the protein patterns coming from the most abundant whey proteins, alpha-lactalbumin and beta-lactoglobulin, used as molecular markers. As no pretreatment of the milk samples is required and owing to the speed and ease of use of MALDI-MS the proposed analytical protocol can be used as a routine strategy for the identification of possible adulteration of the raw fresh milk samples that the dairy industry receives from producers every day.

Cozzolino R ，Passalacqua S ，Salemi S ，Malvagna P ，Spina E ，Garozzo D ... -  《JOURNAL OF MASS SPECTROMETRY》

Identification of adulteration in water buffalo mozzarella and in ewe cheese by using whey proteins as biomarkers and matrix-assisted laser desorption/ionization mass spectrometry.

A rapid and accurate method to identify bovine and ewe milk adulteration of fresh water buffalo mozzarella cheese by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) is described. The differentiation among mozzarella made from water buffalo milk and from mixtures of less expensive bovine and, more recently, ewe milk with water buffalo milk is achieved using whey proteins, alpha-lactalbumin and beta-lactoglobulins as molecular markers. It is worth noting that the method proposed here is, to our knowledge, the first strategy able to characterize possible fraudulent additions of ewe milk in samples of water buffalo milk devoted to the production of water buffalo mozzarella cheese. In addition, a linear relationship was found between the relative response of the molecular ion and the abundance of the analysed whey proteins. This demonstrates that this approach can be used to determine the amount of bovine or ovine milk added to water buffalo milk employed for mozzarella cheese production. Furthermore, this method also appears suitable for the analysis of ewe cheese. Hence these findings open the way to a new field for mass spectrometry in the evaluation of possible fraudulence in dairy industry production.

Cozzolino R ，Passalacqua S ，Salemi S ，Garozzo D ... -  《JOURNAL OF MASS SPECTROMETRY》

MALDI-TOF mass spectrometry for the monitoring of she-donkey's milk contamination or adulteration.

Donkey's milk (DM), representing a safe and alternative food in both IgE-mediated and non-IgE-mediated cow's milk protein allergy, can be categorized as precious pharma-food. Moreover, an economically relevant interest for the use of DM in cosmetology is also developing. The detection of adulterations and contaminations of DM is a matter of fundamental importance from both an economic and allergenic standpoint, and, to this aim, fast and efficient analytical approaches to assess the authenticity of this precious nutrient are desirable. Here, a rapid matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS)-based method aimed to the detection of bovine or caprine milk in raw DM is reported. The presence of the extraneous milks was revealed by monitoring the protein profiles of the most abundant whey proteins, α-lactalbumin (α-LA) and β-lactoglobulin, used as molecular markers. The possibility of obtaining a quantitative analysis of the level of cow or goat milk in DM based on the MALDI-TOF peak areas of α-LAs was also explored. The results showed that the experimental quantitative values were in good agreement with the real composition of each mixture. As pretreatment of the milk samples is not required, and owing to the speed and the high sensitivity of MALDI-MS, the protocol here reported could represent a reliable method for routine analyses aimed to assess the absence of contamination in raw fresh DM samples.

Cunsolo V ，Muccilli V ，Saletti R ，Foti S ... -  《-》

Matrix-assisted laser desorption/ionization mass spectrometry in the dairy industry. 2. The protein fingerprint of ewe cheese and its application to detection of adulteration by bovine milk.

Fanton C ，Delogu G ，Maccioni E ，Podda G ，Seraglia R ，Traldi P ... -  《-》

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

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.

Calvano CD ，De Ceglie C ，Monopoli A ，Zambonin CG ... -  《-》