Observation of Seeding Effects on Fat Bloom of Dark Chocolate

Surface microstructures and polymorphism of seeded dark chocolate were observed with cryo-SEM, to clarify the effects of seeding on fat bloom stability of dark chocolate. Two thermal tests, cycling between 32 adn 20C (32/20) and 38 and 20 C (38/20), were applied to examine the fat bloom stability of the chocolate. We used three crystalline powders: Form VI of cocoa butter; the most stable B1 form of SOS (1,3-distearoyl-2-oleoylglycerol); and the second stable B2 form of BOB (1,3,-dibehenoyl-2-oleoylglycerol) as seed materials. Seeding with cocoa butter (Form VI) and SOS (B1) at concentrations of 0.5 ~ 1 wt. % showed good fat bloom stability in the 32/20 test. In the case of the 38/20 test, however, fat bloom was not prevented. Seeding with BOB (B2) gave the best fat bloom stability in both thermo-cycles; in particular, 5 wt.% BOB (B2) completely prevented fat bloom after the 38/20 test

Molecular frame photoelectron angular distribution for oxygen 1s photoemission from CO_2 molecules

We have measured photoelectron angular distributions in the molecular frame (MF-PADs) for O 1s photoemission from CO2, using photoelectron-O+–CO+ coincidence momentum imaging. Results for the molecular axis at 0, 45 and 90° to the electric vector of the light are reported. The major features of the MF-PADs are fairly well reproduced by calculations employing a relaxed-core Hartree–Fock approach. Weak asymmetric features are seen through a plane perpendicular to the molecular axis and attributed to symmetry lowering by anti-symmetric stretching motion

Carbon K-shell photoelectron angular distribution from fixed-in-space CO2 molecules

Measurements of photoelectron angular distributions for carbon K-shell ionization of fixed-in-space CO2 molecules with the molecular axis oriented along, perpendicular and at 45 degrees to the electric vector of the light are reported. The major features of these measured spectra are fairly well reproduced by calculations employing a relaxed-core Hartree-Fock approach. In contrast to the angular distribution for K-shell ionization of N-2, which exhibits a rich structure dominated by the f-wave (l = 3) at the shape resonance, the angular distribution for carbon K-shell photoionization of CO2 is quite unstructured over the entire observed range across the shape resonance

Fat Polymorphism and Crystal Seeding Effects on Fat Bloom Stability of Dark Chocolate

The effects of seeding with fine crystal powders on the physical properties of dark chocolate are re viewed in terms of the polymorphism and crystallization behavior of cocoa butter (CBJ and of its major fat constituents. The polymorphic structure of four symmetric mixed acids saturated -oleic-saturated (Sat-0- Sat) triacylglycerols (TAGs I [POP (1 ,3-dipalmitoyl-2- oleoyl-glyceroll ;SOS I 1 ,3-distearoyl-2-oleoyl-glycerol); AOA (1 ,3-diarachidoyl-2-oleoyl-glycerol); and BOB 11 ,3-dibehenoyl-2-oleoyl-glyceroi)J. and of tristearoylglycerol (SSSI are briefly explained. An attempt is made at replacing the currently used tempering meth ~ ad in the chocolate solidification process, by a simple cooling technique using fat seed crystals. CB (form VI). SOS 1/i11. BOB (pseudo-/i·l. BOB i/i2), and SSS 1/il are examined as seed materials. The addition of all powders accelerated the crystallization of dark chocolate. Fat bloom stability is also improved by the seed crystals, except w ith SSS. The effect is highly dependent on the physical properties of the seed material employed. The most influencing factors are the similarities in the polymorphic behavior between the seed material and cocoa butter, especially, chain length structure. Thermal stability of the seed crystal is also very important. In view of all physical properties examined, the present review concludes that the p2 form of BOB performs best as a seed material. In particular, it gives rise to an accelerated crystallization of form V of CB and moderates change in viscosity and antibloom effects after thermal incubation of dark chocolate below and above the melting point of CB

Breakdown of the Two-Step Model in K-Shell Photoemission and Subsequent Decay Probed by the Molecular-Frame Photoelectron Angular Distributions of CO_2

We report results of measurements and of Hartree-Fock level calculations of molecular-frame photoelectron angular distributions (MFPADs) for C 1s photoemission from CO2. The agreement between the measured and calculated MFPADs is on average reasonable. The measured MFPADs display a weak but definite asymmetry with respect to the O+ and CO+ fragment ions at certain energies, providing evidence for an overlap of gerade and ungerade final ionic states giving rise to a partial breakdown of the two-step model of core-level photoionization and its subsequent Auger decay

Crystallization and Melting Behavior of Cocoa Butter in Lipid Bodies of Fresh Cacao Beans

The present study aims at observing the crystallization and polymorphic behavior of cocoa butter (CB) in fresh cacao beans with DSC and X-ray diffraction techniques. Underlying idea of this study was to relate the necessary conditions of germination of cacao beans to the crystallization of CB, which are present in oil-in-water emulsion droplets (lipid bodies) with diameters of 1-2 μm. Different cooling and heating conditions, with rates of 15, 2, 0.5, and 0.1 °C/min, were applied to fresh cacao beans and compared to bulk CB. The results showed that the crystallization temperatures (Tc) of CB in fresh cacao beans were lower than those of bulk CB at all the experimental conditions. In addition, polymorphic behavior of the occurrence of metastable and stable forms of CB was also different between the fresh cacao beans and the bulk state. The thermal behavior of fresh and dried cacao beans that have different geographical origins was also analyzed. This study indicates that the germination conditions of cacao beans are extended to low-temperature environmental areas by reducing the Tc value of CB in fresh beans than of the bulk oil. The results were consistent with the germination experiments of fresh cacao beans at different temperatures

MITSuME--Multicolor Imaging Telescopes for Survey and Monstrous Explosions

Development of MITSuME is reported. Two 50-cm optical telescopes have been built at Akeno in Yamanashi prefecture and at Okayama Astrophysical Observatory (OAO) in Okayama prefecture. Three CCD cameras for simultaneous g'RcIc photometry are to be mounted on each focal plane, covering a wide FOV of about 30" x 30". The limiting magnitude at V is fainter than 18. In addition to these two optical telescopes, a 91-cm IR telescope with a 1 deg x 1 deg field of view is being built at OAO, which performs photometry in YJHK bands. These robotic telescopes can start the observation of counterparts of a GRB within a minute from an alert. We aim to obtain photometric redshifts exceeding 10 with these telescopes. The performance and the current construction status of the telescopes are presented.Comment: 4 pages, 3 figures, 4th Workshop on Gamma-Ray Burst in the Afterglow Era, Roma, October 18-22, 200

Photospheric Abundances of Volatile and Refractory Elements in Planet-Harboring Stars

By using the high-dispersion spectra of 14 bright planet-harboring stars (along with 4 reference stars) observed with the new coude echelle spectrograph at Okayama Astrophysical Observatory, we investigated the abundances of volatile elements (C, N, O, S, Zn; low condensation temperature Tc) in order to examine whether these show any significant difference compared to the abundances of other refractory elements (Si, Ti, V, Fe, Co, Ni; high Tc) which are known to be generally overabundant in those stars with planets, since a Tc-dependence is expected if the cause of such a metal-richness is due to the accretion of solid planetesimals onto the host star. We found, however, that all elements we studied behave themselves quite similarly to Fe (i.e., [X/Fe]~0) even for the case of volatile elements, which may suggest that the enhanced metallicity in those planet-bearing stars is not so much an acquired character (by accretion of rocky material) as rather primordial.Comment: 22 pages, 8 figures, to appear in PAS