Use of MALDI-TOF MS technology to evaluate adulteration of small ruminant milk with raw bovine milk.

Detection of adulteration of small ruminant milk is very important for health and commercial reasons. New analytical and cost-effective methods need to be developed to detect new adulteration practices. In this work, we aimed to explore the ability of the MALDI-TOF mass spectrometry to detect bovine milk in caprine and ovine milk using samples from 18 dairy farms. Different levels of adulteration (0.5, 1, 5, 10, 20, 40, 60, and 80%) were analyzed during the lactation period of goat and sheep (in May, from 60 to 90 d in milk, and in August, from 150 to 180 d in milk). Two different ranges of peptide-protein spectra (500-4,000 Da; 4-20 kDa) were used to establish a calibration model for predicting the concentration of adulterant using partial least squares and generalized linear model with lasso regularization. The low molecular weight part of the spectra together with the generalized linear model with lasso regularization regression model appeared to have greater potential for our aim of detection of adulteration of small ruminants' milk. The subsequent prediction model was able to predict the concentration of bovine milk in caprine milk with a root mean square error of 11.4 and 17.0% in ovine milk. The results offer compelling evidence that MALDI-TOF can detect the adulteration of small ruminants' milk. However, the method is severely limited by (1) the complexity of the milk proteome resulting from the adulteration technique, (2) the potential degradation of thermolabile proteins, and (3) the genetic variability of tested samples. Additionally, the root mean square error of prediction based only on one individual sample adulteration series can drop down to 6.34% for quantification of adulterated caprine milk and 6.28% for adulterated ovine milk for the full set of concentrations or down to 2.33 and 4.00%, respectively, if we restrict only to low concentrations of adulteration (0, 0.5, 1, 5, 10%).

Detection of bovine milk adulteration in caprine milk with N-acetyl carbohydrate biomarkers by using 1H nuclear magnetic resonance spectroscopy.

In a return to tradition, the popularity of caprine milk is on the rise. However, particularly in countries with developed dairy industries based on bovine milk, there is the risk of adulteration with bovine milk, which is a cheaper alternative. Thus, a rapid, robust, and simple method for the detection of bovine milk added to caprine milk is necessary, and 1H nuclear magnetic resonance spectroscopy appears to provide a solution. A matrix of 115 pure and artificially adulterated pasteurized milk samples was prepared and used to discover biomarkers of bovine milk that are independent of chemical and biological variation caused by factors such as genetics, diet, or seasonality. Principal component analysis and orthogonal projections to latent structures discriminant analysis of pure bovine milk and pure caprine milk revealed spectral features that were assigned to the resonances of 4 molecules. Of these, the peaks corresponding to protons in the N-acetylglucosamine and N-acetylgalactosamine acetyl moieties showed significant applicability for our method. Receiver operating characteristic curve analysis was used to evaluate the performance of the peak integrals as biomarkers of adulteration. This approach was able to distinguish caprine milk adulterated with 5% of bovine milk with 84.78% accuracy and with 10% of bovine milk an excellent 95.65% accuracy. This study demonstrates that N-acetyl carbohydrates could be used as biomarkers for the detection of bovine milk in caprine milk and could help in protecting caprine milk authenticity.

Clinical correlations of potential activity markers in systemic sclerosis.

The objectives of the project were the following: (1) to establish a group of patients with a confirmed diagnosis of systemic sclerosis (Ssc), (2) to perform a detailed entrance examination of each patient, (3) to determine concentrations of potential activity markers, and (4) to make a comprehensive examination of each patient 1 year after inclusion into the study. A total of 49 patients were examined, 36 with a limited form of SSc, 9 with diffuse SSc, and 4 with other forms of SSc. We determined plasma or serum levels of the N-terminal propeptide of procollagen type III (NPIIIP), interleukin-6 (IL-6), soluble receptor for interleukin-2 (sIL-2r), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular adhesion molecule-1 (sVCAM-1), von Willebrand factor antigen (vWFAg), and big endothelin-1 (BET-1) using commercial kits, and urinary excretion of pyridinoline (PYR) and deoxypyridinoline (D-PYR) using high-performance liquid chromatography. Correlations of these markers with selected clinical data were calculated. The mean levels of all potential activity markers were increased compared with normal values, but differences were not significant. The levels of NPIIIP, D-PYR, and IL-6 were normal. The measured values after 1 year did not differ from the entry values. At entry, NPIIIP concentrations correlated with the finger-to-palm distance, and D-PYR corresponded with findings on a simplified health assessment questionnaire (FQ). IL-6 levels correlated with the leukocyte count, sIL-2r with the FQ, and ET-1 with the diffuse lung capacity for carbon monoxide. In general, we found only a few clinical correlates of potential activity markers. Our data confirmed the correlations of collagen metabolism markers with skin involvement and FQ, as was reported previously. Larger studies in this field are needed.