Relative quantification of pork and beef in meat products using global and species-specific peptide markers for the authentication of meat composition.

We used global and species-specific peptide markers for a relative quantitative determination of pork and beef in raw and processed meat products made of the two meat species. Four groups of products were prepared (i.e., minced raw meats, sausages, raw and fried burgers) in order to represent products with different extents of food processing. In each group, the products varied in the pork/beef proportions. All products were analysed by multiple reaction monitoring mass spectrometry (MRM-MS) for the presence/concentration of pork- and beef-specific peptide markers, as well as global markers - peptides widely distributed in muscle tissue. The combined MRM-MS analysis of pork-specific peptide HPGDFGADAQGAMSK, beef-specific peptide VLGFHG and global marker LFDLR offered the most reliable validation of declared pork/beef compositions across the whole range of meat products. Our work suggests that a simultaneous analysis of global and species-specific peptide markers can be used for composition authentication in commercial pork/beef products.

Occurrence and Levels of Biogenic Amines in Beers Produced by Different Methods.

The concentration of biogenic amines (BAs) in beer depends, among other factors, on the activity of microorganisms, in particular lactic acid bacteria. In this work an analytical method based on derivatization with tosyl chloride and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to determine 17 BAs in samples of commercially available beers, and to monitor the changes in concentration of several BAs throughout the fermentation process. In some of the analysed samples the concentration of BAs exceeded the safety threshold for consumers. During the fermentation stage of home-brewing of ale the concentration of spermine in the wort increased until the end of the stormy fermentation, to then drop below the initial concentration at the end of fermentation, and below the LOQ after refermentation. The results of the study indicate that monitoring the total content of BAs is required due to the potential risk to human health.

MRM-MS of marker peptides and their abundance as a tool for authentication of meat species and meat cuts in single-cut meat products.

The abundance of protein markers in different types of meat cuts was explored in the context of authentication of raw meat (pork, beef and chicken) and processed meat products. Peptides originating from myoglobin (Mb) and myosin (My) were analyzed using multiple reaction monitoring mass spectrometry (MRM-MS). Analytical protocol was optimized for good repeatability (CV < 10%) and high sensitivity. The MS signal intensity of Mb marker peptides in raw pork depended significantly on the cut type (e.g. ham vs knuckle). Importantly, a similar pattern in the abundance of the marker peptides was found for processed meat products made of different types of pork cuts, despite the food processing applied. This suggests the protocol can be used for authentication of raw pork cuts and processed products made of different cuts of pork. More uniform contents of Mb markers were found in raw beef cuts, and for My markers in raw chicken cuts.

Development and validation of an LC-MS/MS method for the determination of biogenic amines in wines and beers.

ABSTRACT: Biogenic amines are group of organic, basic, nitrogenous compounds that naturally occur in plant, microorganism, and animal organisms. Biogenic amines are mainly produced through decarboxylation of amino acids. They are formed during manufacturing of some kind of food and beverages such as cheese, wine, or beer. Histamine, cadaverine, agmatine, tyramine, putrescine, and ß-phenylethylamine are the most common biogenic amines found in wines and beers. This group of compounds can be toxic at high concentrations; therefore, their control is very important. Analysis of biogenic amines in alcoholic drinks (beers and wines) was carried out by HPLC-MS/MS after their derivatization with p-toluenesulfonyl chloride (tosyl chloride). The developed method has been applied for analysis of seventeen biogenic amines in twenty-eight samples of lager beers and in twelve samples of different homemade wines (white grape, red grape, strawberry, chokeberry, black currant, plum, apple, raspberry, and quince). The developed method is sensitive and repeatable for majority of the analytes. It is versatile and can be used for the determination of biogenic amines in various alcoholic beverages.