Grape seeds proanthocyanidins: Advanced technological preparation and analytical characterization

A “green” solvent-free industrial process (patent pending) is here described for a grape seed extract (GSE) preparation (Ecovitis™, Spain) obtained from selected seeds of Veneto region wineries, in the northeast of Italy, by water and selective tangential flow filtration at different porosity. Since a comprehensive, non-ambiguous characterization of GSE is still a difficult task, we resorted to using an integrated combination of gel permeation chromatography (GPC) and electrospray ionization high resolution mass spectrometry (ESI-HRMS). By calibration of retention time and spectroscopic quantification of catechin as chromophore, we succeeded in quantifying GPC polymers up to traces at n = 30. The MS analysis carried out by the ESI-HRMS method by direct-infusion allows the detection of more than 70 species, at different polymerization and galloylation, up to n = 13. This sensitivity took advantage of the nanoscale shotgun approach, although paying the limit of missed separation of stereoisomers. GPC and MS approaches were remarkably well cross-validated by overlapping results. This simple integrated analytical approach has been used for quality control of the production of Ecovitis™. The emerging feature of Ecovitis™ vs. a popular benchmark in the market, produced by a different technology, is the much lower content of species at low n and the corresponding increase of species at high n

Are Trojan collisional families a source for short--period comets?

We have investigated the dynamical evolution of fragments generated by the impact breakup of Trojan asteroids, in order to study the formation of collisional families in the Trojan clouds and to identify a possible genetic connection between these fragments and the population of short-period comets. Using a collisional model based on the results of high-velocity laboratory impact experiments and previously applied to main-belt asteroid families, we show that typical family-forming Trojan collisions eject a significant percentage (at least =~20%) of the resulting fragments onto unstable orbits. Numerical integrations of the orbits of such fictitious, unstable Trojan fragments show that soon they experience close encounters with Jupiter, and as a consequence they become undistinguishable from those of Jupiter-family comets (some of which are currently close to the 1:1 Jovian resonance), of comets undergoing temporary satellite captures by Jupiter (such as P/Shoemaker-Levy 9), and of objects with Jupiter-crossing or -approaching orbits (such as 944 Hidalgo, 2060 Chiron, 5145 Pholus and 3552 Don Quixote). A reliable assessment of the efficiency of the transfer process from the Trojan clouds into comet-type orbits and of its time dependence is difficult, owing in particular to the poorly known size distribution of Trojans. However, an order-of-magnitude estimate suggests that if the fragment flux from the Trojan clouds over the last =~10^6^yr has been close to the average one over the solar system's lifetime, then a few tens of the 160 known short-period comets might have been generated by Trojan collisions

Updated collisional probabilities of minor body populations

The consistent increase in the discovery rate of new asteroids and Trans Neptunian Objects (TNOs) in these last years has urged an update of the values of intrinsic probability of collision and impact velocity for some minor body populations. With the statistical method of Dell'Oro & Paolicchi ([CITE]), we have recomputed the values of impact probability and velocity for Hilda asteroids, for Trojans vs. Short Period Comets (SPC), and for TNOs. The algorithm of Dell'Oro and Paolicchi is particularly suited for the task since it can account for resonant behaviour (Dell'Oro et al. [CITE]) and for the clustering of the perihelion longitude of Main Belt asteroids and Hildas, caused by the presence of a forced component in the eccentricity. The Hilda population turns out to be well sampled in the orbital parameter space since no significant changes are found for the collision frequency among Hildas, and of Hildas with Main Belt asteroids, although a much larger sample of orbits has been used in our computations (232 objects) vs. the smaller group used in previous computation by Dahlgren ([CITE]) (40 objects). We also computed the impact rate of SPCs vs. Trojans that turned out to be an order of magnitude lower respect to the Trojans vs. Trojans impact rate. The relative velocity is instead about 30% higher. Using reasonable estimates of SPC and Trojan number densities, we find that approximately 1 every 100 collisions involving Trojans may be with an SPC. In the case of TNOs there is a consistent discrepancy between our values of the collision probability and impact speed, and those computed by Davis & Farinella ([CITE]). The consistent increase in the number of known TNOs (186 at present, only 16 at the time of the Davis and Farinella's work) has led to a better knowledge of their distribution in the phase space and, consequently, to more reliable estimates of the collisional probability and impact velocity

Red Chicories as potent scavengers of highly reactive radicals: a study on their phenolic composition and peroxyl radical trapping capacity and efficiency

Eight varieties of Cichorium genus vegetables (five heavily red colored, one red spotted, and two fully green) were investigated for their phenolic content (by HPLC and UV-vis spectrophotometry) and for their antioxidant activity. In particular, the capacity (that is, the amount of trapped peroxyl radicals) and the efficiency (that is, the amount of antioxidant necessary to halve the steady-state concentration of peroxyl radicals) were measured. All of the studied chicories are characterized by the presence of a large amount of hydroxybenzoic and hydroxycinnamic acids, whereas the red color is due to cyanidin glycosides. The presence of these phenolics in red chicories confers to them an exceptionally high peroxyl radical scavenging activity in terms of both capacity and efficiency, particularly in their early stage of growth, and makes this popular and low-cost foods comparable or superior to many foods having well-known antioxidant properties such as red wine, blueberry, and tomato

Trojan collision probability: a statistical approach

We study the long term evolution of the collision probability and of the impact velocity vimp in the two Trojan asteroid swarms. The new mathematical formalism by Dell'Oro and Paolicchi (1998) has been used since, in the calculation of the collision probability, it allows to account for the dynamical links among the Trojans and Jupiter orbital angles, due to the 1:1 resonance. This statistical method permits to compute both and vimp over a long timespan (we considered 1 Myr) without making use of heavy numerical integrations. Moreover, it allows to easily update the values of and vimp anytime more complete samples of Trojan orbits are available. The values of and vimp over a short timescale have been compared to those of Marzari et al. (1997) and a good agreement has been observed. Over a long timescale the influence of the secular frequency g5-g6 is clearly visible in . The large oscillations due to the secular frequency are wider for L4 than for L5. We have considered two different initial samples of orbits. The first is the same sample used by Marzari et al. (1997) and includes the orbits of 114 Trojans. The second, more complete, includes 223 objects. We observe an increase of in both the swarms when the more complete sample of Trojan orbits (223) is used. The vimp, instead, slightly decreases compared to the vimp found by Marzari et al. (1997) from the sample of 114 Trojans