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Milk and cheese are expensive foodstuffs, and their consumption is spread among the population because of their high nutritional value; for this reason they are often subjected to adulterations. Among the common illegal practices, the addition of powdered derivatives seems very difficult to detect because the adulterant materials have almost the same chemical composition of liquid milk. However, the high temperatures (180-200 °C) used for milk powder production could imply the occurrence of some protein modifications (e.g., glycation, lactosylation, oxidation, deamidation, dehydration). The modified proteins or peptides could then be used as markers for the presence of powdered milk. In this work, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was employed to analyze tryptic digests relevant to samples of raw liquid (without heat treatment), commercial liquid, and powdered cow's milk. Samples were subjected to two-dimensional gel electrophoresis (2-DE); differences among liquid and powder milk were detected at this stage and eventually confirmed by MALDI analysis of the in gel digested proteins. Some diagnostic peptides of powdered milk, attributed to modified whey proteins and/or caseins, were identified. Then, a faster procedure was optimized, consisting of the separation of caseins from milk whey and the subsequent in-solution digestion of the two fractions, with the advantage of obtaining almost the same information in a limited amount of time. Finally, analyses were carried out with the fast procedure on liquid milk samples adulterated with powdered milk at different percentages, and diagnostic peptides were detected down to 1% of adulteration level.

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The effect of a multiple strain starter (KSL: Kocuria varians, Staphylococcus xylosus and Lactobacillus sakei) on the quality of soppressata molisana was investigated during 50 days of ripening. When compared with control batches (C, traditional production without starter and KS, addition of K. varians and S. xylosus as starter), soppressata produced with KSL showed positive results in terms of proteolysis progression, reduction of biogenic amines (BA) and sensory features. The partial substitution of 50 % NaCl with 50 % KCl further improved the quality of soppressata molisana produced with KSL as starter. In fact, the K+ ions seemed to stimulate the growth of added bacteria, with a resulting additional lowering of the pH and BA formation, and higher proteolysis. Moreover, the addition of KCl did not alter the sensory profile of final products. The analysis of data collected during the fermentation and the drying phases, which followed one other, allowed the individuation of different proteolytic events. Specifically, the proteolysis of the myofibrillar fraction occurred more slowly than that of the sarcoplasmic one. Also, the analysis of fractionated muscle proteins allowed to appreciate that sarcoplasmic proteins were hydrolyzed by both endogenous and microbial enzymes, whereas myofibrillar proteins showed a higher resistance to microbial enzymes, and were primarily hydrolyzed by endogenous ones. In conclusion the combined use of KSL and KCl as partial substitute of NaCl, allowed the production of soppressata molisana having an excellent quality, and features consistent with the guidelines of WHO on the sodium and potassium intake