Comprehensive study of honey with protected denomination of origin and contribution to the enhancement of legal specifications

In this study the characterization of a total of 60 honey samples with Protected Denomination of Origin (PDO) collected over three harvests (2009-2011, inclusive), from the Northeast of Portugal was carried out based on the presence of pollen, physicochemical and microbiological characteristics. All samples were found to meet the European Legislation, but some didn't meet the requirements of the PDO specifications. Concerning the floral origin of honey, our results showed the prevalence of rosemary (Lavandula pedunculata) pollen. The microbiological quality of all the analyzed samples was satisfactory, since fecal coliforms, sulfite-reducing clostridia and Salmonella were absent, and molds and yeasts were detected in low counts. Significant differences between the results were studied using one-way analysis of variance (ANOVA), followed by Tukey's HSD test. The samples were submitted to discriminant function analysis, in order to determine which variables differentiate between two or more naturally occurring groups (Forward Stepwise Analysis). The variables selected were in this order: diastase activity, pH, reducing sugars, free acidity and HMF. The pollen spectrum has perfect discriminatory power. This is the first study in which a honey with PDO was tested, in order to assess its compliance with the PDO book of specifications.     

Van Kampen's expansion approach in an opinion formation model

We analyze a simple opinion formation model consisting of two parties, A and B, and a group I, of undecided agents. We assume that the supporters of parties A and B do not interact among them, but only interact through the group I, and that there is a nonzero probability of a spontaneous change of opinion ( , ). From the master equation, and via van Kampen's Ω-expansion approach, we have obtained the “macroscopic” evolution equation, as well as the Fokker-Planck equation governing the fluctuations around the deterministic behavior. Within the same approach, we have also obtained information about the typical relaxation behavior of small perturbations. An erratum to this article is available at .     

Eight-channel ultrasonic device for non-invasive quality evaluation in packed milk

An eight-channel ultrasonic detecting device for microbiological quality evaluation of packed liquid foods is presented in this paper. This device makes possible a non-invasive detection of the microbial growth in liquid foods with no need to open the carton-based packages where they are contained. Thermal and humidity stabilization are required inside the measuring chamber. The changes in the liquid media produced by the microorganism growth induce variations in the ultrasonic propagation parameters giving a non-invasive evidence of the developing contamination. For that purpose, the amplitude and time of flight of an ultrasonic 800 kHz tone burst travelling through an UHT milk pack are analysed. Inoculated and sterile packs were tested to evaluate the performance of this new non-invasive ultrasonic microbiological quality sensor.     

Approaching the Kinetic Inertness of Macrocyclic Gadolinium(III)‐Based MRI Contrast Agents with Highly Rigid Open‐Chain Derivatives

A highly rigid open‐chain octadentate ligand (H₄cddadpa) containing a diaminocylohexane unit to replace the ethylenediamine bridge of 6,6′‐[(ethane‐1,2 diylbis{(carboxymethyl)azanediyl})bis(methylene)]dipicolinic acid (H₄octapa) was synthesized. This structural modification improves the thermodynamic stability of the Gd³⁺ complex slightly (log K_GdL=20.68 vs. 20.23 for [Gd(octapa)]^?) while other MRI‐relevant parameters remain unaffected (one coordinated water molecule; relaxivity r₁=5.73 mm ^?1 s^?1 at 20 MHz and 295 K). Kinetic inertness is improved by the rigidifying effect of the diaminocylohexane unit in the ligand skeleton (half‐life of dissociation for physiological conditions is 6 orders of magnitude higher for [Gd(cddadpa)]^? (t_1/2=1.49×10⁵ h) than for [Gd(octapa)]^?. The kinetic inertness of this novel chelate is superior by 2–3 orders of magnitude compared to non‐macrocyclic MRI contrast agents approved for clinical use.