S. De Angelis Curtis

Amino acid profile in the ripening of Grana Padano cheese : a NMR study

Among typical Italian cheeses, Grana Padano is the most famous, with the biggest production. The final step in the cheesemaking is the natural ripening, which involves many modifications of high complexity. In the present work, thermoanalytical and spectroscopic techniques are applied to Grana Padano cheese as a new analytical approach. These are thermogravimetry (TG) and derived thermogravimetry (DTG) to determine different types of water present in the cheese matrix, low-resolution nuclear magnetic resonance (NMR) to provide information on the water localization and displacements within the foodstuff and high-resolution nuclear magnetic resonance (NMR) to evaluate all the amino acids present in the cheese. Modifications in both water and free amino acid contents are observed, as a function of the ripening time and of the distance from the centre of the cheese wheel.

Thermogravimetric characterization of dark chocolate

Dark chocolate is a complex food product in which sugar crystals and cocoa particles are surrounded by cocoa butter. Thermogravimetry and derivative thermogravimetry are proposed as fast, cheap, and sensitive tools to determine the composition of dark chocolate and consequently to confirm the cocoa percent declared by the producer or to check the production cycle.

Thermal analytical techniques applied to the narcotic field: cocaine analysis

Abstract The cocaine sold in the illegal market is normally a mixture of cocaine with different kinds of cuts. For legal purposes, it is compulsory to know the exact quantity of cocaine present in each sequestered sample, while at the same time it is important to know the type of cuts used. The analytical methods commonly used are not very reliable and take a long time. In this paper, the use of thermoanalytical techniques is suggested for the direct analysis of cocaine and cuts without any preliminary sample treatment, thus avoiding artifacts due to the sample pretreatment or to the analytical operative conditions. The proposed method is time saving and reliable with a maximum analytical error of the order of about 4%, while the mean error is of the order of about 2%.

Grana Padano cheese : thermoanalytical techniques applied to the study of ripening

Abstract In the present work, modifications of water–matrix interactions in Grana Padano (GP) cheese were studied using thermogravimetric techniques in order to provide an index of ripening. These techniques represent a simple and rapid method for determining water content and for monitoring its behaviour in ripening GP cheese. It is possible to evaluate the quantity of water present in the matrix, as well as the different types of water bound to it both qualitatively and quantitatively. Samples of traditional GP cheese produced in the winter season (same day), and collected at different ripening stages (5,10,14,19 months), were investigated. When statistical models of the STARMAX (Space Time Autoregressive Moving Average eXogenous variables) class, augmented with surface trends, were fitted to thermoanalytical data, valuable insights into the chemical nature of the ripening were acheived with good predictive performances.

Rapid liquid chromatographic analysis of carboxylic acid-5-hydroxytryptamides in coffee

SummaryCarboxylic acid 5-hydroxytryptamides have been determined by reversed-phase high performance liquid chromatography with isocratic elution and fluorimetric detection (λex 280 nm, λem 340 nm). The procedure described involves the direct injection into the HPLC system of the solution obtained by ultrasonic extraction of the coffee. The results obtained were compared with those obtained by procedures proposed in the literature. The method was applied to different types of coffee (raw, roasted, decaffeinated and dewaxed). A purification method for determining traces of C-5-HT present in coffee infusions is also described.

ATPase Na, K-dependent activity and water-matrix interactions in cerebella of aged mice

Abstract A new analytical approach to the chemical behaviour of mouse cerebella during ageing is described. The microcalorimetric determination of Na + /K + -ATPase activity and the thermogravimetric investigation of the water–matrix interactions were performed on cerebella of mice of 2, 10 and 22 months (young, adult and aged mice). The results are compared with a preceding work regarding the same determinations performed on cerebella of ouabain-treated mice (spongy-state induced in cerebella of mice as those affected by the Jacob–Creutzfeld disease) and also with similar studies on ageing of brain in mice reported in the literature. The results here obtained on cerebella of aged mice show a substantial difference with respect to those reported for analogous samples of mice affected by a spongy-state.

Modifications induced on water-matrix interactions and on ATPase, Na,K-dependent activity in ouabain-treated cerebella of mice

Abstract In a biological system, water can be bound to the matrix with different energies and thus, when the latter is heated, be lost at subsequent stages according to the activation energies required to obtain the release of the different types of water. In this sense, particularly when combined with ancillary systems such as FT-IR spectroscopy, thermoanalytical techniques allow us to distinguish all the different types of water contained in a biological system. Using this approach, the water in the cerebellum of mice treated by subdural inoculation of ouabain (G-strophanthin) was studied. At the same time, the activity of Na,K-ATPase was followed in treated and untreated mice cerebella by means of calorimetry. The activity decreases as a function of the time elapsing between inoculation and the animals death. Experimental data are discussed in terms of inhibition of Na,K-ATPase and in terms of the modified water-matrix interaction, consequent to the changed mechanism of the diffusion transport deriving from the gradient in Na-ion concentration between the inside and outside of the cell wall.

Cattle breeding : A fast screening procedure to control the bovine fodder contamination

The European Commission has adopted a large number of emergency measures to prevent the spread of the Bovine spongiform encephalopathy (BSE) in the Member States, and among them, a European Regulation prohibits the feeding to ruminants of animal protein and animal feed containing such protein. Aim of this work has been to propose the thermal analysis as a new rapid and sensitive screening tool for a preliminary determination of possible contamination in products destined to bovine growth, since the possibility to screen the samples by a rapid and sensitive tool could reduce the time of analysis required by the actual methodology and could allow the systematic surveillance of bovine feeding, with the official EU methods applied only to positive samples.