Effect of different physical treatments on antioxidant activity of jenny milk

The shelf life of food can be extended by employing several physical treatments. Among them, pasteurization and condensation are widely adopted for prolonging the shelf-life of milk by reducing the microbial load. However, these treatmens could affect the antioxidant activity of the product. The aim of the present study was to investigate the effect of pasteurization and condensation on the Total Antioxidant Capacity (TAC) of raw and pasteurised jenny milk. Using 2,2’-azinobis (3-ethylbenzthiazoline-6-acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. TAC was also measured after condensation at 40 and at 20% of the initial volume. ABTS assay was found to be more accurate and reproducible than DPPH. Pasteurisation reduced significantly (P<0.05) the total antioxidant capacity from 84.15to 82.09% (ABTS test). The TAC decreased with the increase of condensation in raw and pasteurised milk. Overall, the TAC was reduced by only 3 and 4%, in pasteurised and in raw milk, respectively (ABTS test). Therefore, both pasteurization and condensation are recommended as physical treatments to prolong the shelf-life of jenny milk

use of technical and economical parameters for evaluating dairy cow ration efficiency

The aim of this study was the development of a model for evaluating dairy cow ration efficiency. This model took into account technical, metabolic, and economic parameters, which were divided into two main categories: input and output. Feeding (food administered and its nutritional characteristics) was considered as the input parameter. The output indicators were directly or indirectly correlated with feeding, and included: quality and quantity of milk, body condition score, live weight, reproductive parameters, incidence of animal diseases (laminitis), undigested fraction, fecal consistency, feed efficiency (FE), and income over feed cost (IOFC). The model was validated using ten dairy farms located in the northwest of Basilicata. The farms were divided into two groups (A and B) as a function of the urea level in bulk milk. In Group A, the urea level was between 25 and 31 mg/100 mL milk, whereas, in Group B, the range was 21-22.5 mg/100 mL milk. The model showed that the values of reproductive parameters were worse in Group A than in Group B. However, the Group A showed better milk qualitative and quantitative characteristics, such as a high average production per head (28.15 vs 26.93 kg), and a high fat (3.92 vs 3.71%) and protein (3.53 vs 3.37%) content of bulk milk. Moreover, the highest values of FE (1.45 vs 1.35 kg milk/kg dry matter) and IOFC (6.07 vs 5.32 €) were found in Group A. The model clearly showed that the administration of unbalanced rations, based on the physiological stage of the animals, negatively affected both the qualitative and quantitative characteristics of milk, as well as the reproductive performances. The administration of unbalanced rations for the energy/protein content caused dysmetabolic syndromes, which led to a reduction of both FE and IOFC. This, ultimately, caused a fall in the overall farm profitability

Identification and fragmentation pathways of caffeine metabolites in urine samples via liquid chromatography with positive electrospray ionization coupled to a hybrid quadrupole linear ion trap (LTQ) and Fourier transform ion cyclotron resonance mass spectrometry and tandem mass spectrometry.

Liquid chromatography (LC) with positive ion electrospray ionization (ESI+) coupled to a hybrid quadrupole linear ion trap (LTQ) and Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) was employed for the simultaneous determination of caffeine and its metabolites in human urine within a single chromatographic run. LC/ESI-FTICRMS led to the unambiguous determination of the molecular masses of the studied compounds without interference from other biomolecules. A systematic and comprehensive study of the mass spectral behaviour of caffeine and its fourteen metabolites by tandem mass spectrometry (MS/MS) was performed, through in-source ion trap collision-induced dissociation (CID) of the protonated molecules, [M+H](+). A retro-Diels-Alder (RDA) process along with ring-contraction reactions were the major fragmentation pathways observed during CID. The base peak of xanthine precursors originates from the loss of methyl isocyanate (CH(3)NCO, 57 Da) or isocyanic acid (HNCO, 43 Da), which in turn lose a CO unit. Also uric acid derivatives shared a RDA rearrangement as a common fragmentation process and a successive loss of CO(2) or CO. The uracil derivatives showed a loss of a ketene unit (CH(2)CO, 42 Da) from the protonated molecule along with the loss of H(2)O or CO. To assess the potential of the present method three established metabolite ratios to measure P450 CYP1A2, N-acetyltransferase and xanthine oxidase activities were evaluated by a number of identified metabolites from healthy human urine samples after caffeine intake

“FRAGMENTATION STUDY OF CAFFEINE AND ITS XANTHINE METABOLITES IN URINE SAMPLES BY LC-ESI-MS AND TANDEM MS”

Comunicazione POSTER

Analisi dei metaboliti della caffeina in campioni di urina mediante LC-ESI-FTICR-MS e spettrometria di massa tandem in trappola ionica lineare (LTQ)

Comunicazione POSTER

Identification and fragmentation pathways of caffeine metabolites in urine samples via combined LC-ESI-LTQ-FTICRMS and tandem mass spectrometry

Liquid chromatography (LC) with positive ion electrospray ionization (ESIR) coupled to a hybrid quadrupole linear ion trap (LTQ) and Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) was employed for the simultaneous determination of caffeine and its metabolites in human urine within a single chromatographic run. LC/ESI-FTICRMS led to the unambiguous determination of the molecular masses of the studied compounds without interference from other biomolecules. A systematic and comprehensive study of the mass spectral behaviour of caffeine and its fourteen metabolites by tandem mass spectrometry (MS/MS) was performed, through in-source ion trap collision-induced dissociation (CID) of the protonated molecules, [MRH]R. A retro-Diels- Alder (RDA) process along with ring-contraction reactions were the major fragmentation pathways observed during CID. The base peak of xanthine precursors originates from the loss of methyl isocyanate (CH3NCO, 57 Da) or isocyanic acid (HNCO, 43 Da), which in turn lose a CO unit. Also uric acid derivatives shared a RDA rearrangement as a common fragmentation process and a successive loss of CO2 or CO. The uracil derivatives showed a loss of a ketene unit (CH2CO, 42 Da) from the protonated molecule along with the loss of H2O or CO. To assess the potential of the present method three established metabolite ratios to measure P450 CYP1A2, N-acetyltransferase and xanthine oxidase activities were evaluated by a number of identified metabolites from healthy human urine samples after caffeine intake

Scrambling of autoinducing precursor-peptides investigated by infrared multiphoton dissociation with electrospray ionization and Fourier-transform ion cyclotron resonance mass spectrometry

Two synthetic precursor peptides, H2N-CVGIW and H 2N-LVMCCVGIW, involved in the quorum sensing of Lactobacillus plantarum WCFS1, were characterized by mass spectrometry (MS) with electrospray ionization and 7-T Fourier transform ion cyclotron resonance (ESI-FTICR) instrument. Cell-free bacterial supernatant solutions were analyzed by reversed-phase liquid chromatography with ESI-FTICR MS to verify the occurrence of both pentapeptide and nonapeptide in the bacterial broth. The structural characterization of both protonated peptides was performed by infrared multiphoton dissociation using a continuous CO2 laser source at a wavelength of 10.6 μm. As their fragmentation behavior cannot be directly derived from the primary peptide structure, all anomalous fragments were interpreted as neutral loss of amino acids from the interior of both peptides, i.e., loss of V, G, VG and M, MC, V, CC, from H2N-CVGIW and H 2N-LVMCCVGIW, respectively. Mechanisms of this scrambling are proposed. FTICR MS provides accurate masses of all fragment ions with very low absolute mass errors (<1.6 ppm), which facilitated the reliable assignment of their elemental compositions. The resolving power was more than sufficient to resolve closely isobaric product ions with routine subparts per million mass accuracies. Only the occurrence of pentapeptide was found in the cell-free culture of L. plantarum, grown in Waymouth's medium broth, with a low content of 5.2 ± 2.6 μM by external calibration. Most of it was present as oxidized H2N-CVGIW, that is, the soluble disulfide pentapeptide with a level tenfold higher (i.e., 50 ± 4 μM, n = 3)