The Development of Butterfly pea (Clitoria ternatea) Flower Powder Drink by Co-crystallization

Abstract— A method consist of co-crystallization, agglomeration, drying has been applied to develop a powder drink from butterfly pea flower (Clitoria ternatea) extract. The butterfly pea flower extract was concentrated by vacuum evaporation and incorporated with supersaturated sugar solution (more than 90 Brix), agglomerated and dried at 60oC for 12 hours. The anthocyanin stability and antioxidant activity of the powder drink was evaluated for 28 days at three levels of temperature (room temperature, 40oC, and 50oC). The stability of anthocyanin decreased as the increase of storage temperature. The half-life of anthocyanin in the powder drink at respective temperature was 27.99, 16.53, and 9.81 days. Despite the anthocyanin significantly degraded, the decrease of antioxidant activity of the powder drink was not significant. Hence, the beneficial effect of the butterfly pea powder drink retained. Keywords— anthocyanin; butterfly pea; co-crystallization; stability; sugar

Crystallization Stability of Sb2O3 -Doped Vanadium Phosphate Sealing Glass Analyzed by XPS

The mechanism of the increased crystallization stability (the difference between glass incipient crystallization temperature and transition temperature) of Sb2O3 —doped vanadium phosphate sealing glass investigated by X-ray photoelectron spectroscopy (XPS) is reported in the present study. Experimental results showed that after doping with Sb2O3, the rate of bridging oxygen increased while the rate of no-bridging oxygen decreased, and the ratio of V4+/Vtotal also increased, too. This two changes led to the break of V=0 bond which is essential for the formation of V2O5 crystalline phase, thus inhibited the formation of that crystalline phase and improved glass crystallization stability.

Spatial Localization of the Nucleation Rate in Deeply Undercooled Liquids

In bulk metallic glass forming alloys cooled close to the critical cooling rate for glass formation, the nucleation density is observed to be spatially inhomogeneous; in an amorphous matrix there are spherical clusters with a high density of nanocrystals. This is attributed to the combined effect of recalescence due to the heat of crystallization and the fact that in deeply undercooled liquids the nucleation rate increases with increasing temperature.A linear stability analysis of the non-linear differential equations describing nucleation and growth reveals that in the early stages of crystallization, stability is determined by the temperature dependence of the nucleation rate. When the nucleation rate increases with increasing temperature, fluctuations are amplified, resulting in “hot spots” where both the nucleation rate and the growth rate are higher.