Crocin loaded nano-emulsions: Factors affecting emulsion properties in spontaneous emulsification

Spontaneous emulsification may be used for encapsulating bioactive compounds in food and pharmaceutical industry. It has several advantages over high energy and other low energy methods including, protecting sensitive compounds against severe conditions of high energy method and its ability to minimize surfactant, removal of cosurfactant and thermal stability compared with other low energy methods. In this study, we examined possibility of encapsulating highly soluble crocin in W/O micro-emulsions using spontaneous method which further could be used for making double emulsions. Nonionic surfactants of Span 80 and polyglycerol polyricinoleate (PGPR) were used for making micro-emulsions that showed the high potential of PGPR for spontaneous method. Surfactant to water ratio (SWR) was evaluated to find the highest amount of aqueous phase which can be dispersed in organic phase. Droplet size decreased by increasing SWR toward the SWR = 100 which had the smallest droplet size and then increased at higher levels of surfactant. By increasing SWR, shear viscosity increased which showed the high effect of PGPR on rheological properties. This study shows in addition to W/O micro-emulsions, spontaneous method could be used for preparing stable O/W micro-emulsions. © 2015 Elsevier B.V

Classical tests in brane gravity

The vacuum solutions in brane gravity differ from those in 4D by a number of additional terms and reduce to the familiar Schwarzschild metric at small distances. We study the possible roles that such terms may play in the precession of planetary orbits, bending of light, radar retardation and the anomaly in mean motion of test bodies. Using the available data from Solar System experiments, we determine the range of the free parameters associated with the linear term in the metric. The best results come from the anomalies in the mean motion of planets. Such studies should shed some light on the origin of dark energy via the solar system tests.Comment: 10 pages, no figures, to appear in CQ

Measurement of toxic elements in infant food supplements marketed in Iran (short comunication)

Due to similarities with breast-feeding, baby food is used as a partial replacement for babies between 6 to 12 months of age. In this study, five samples of famous infant food supplement consisting of three types from Ghoncheh company (rice with milk, wheat with milk, almond porridge) and two types from Nestle company (wheat and milk, and banana and wheat with milk) were prepared. Samples were digested with nitric acid and the concentrations of cadmium, lead, manganese, molybdenum and nickel were analyzed. In addition, the estimated daily intake (EDI) index for all samples was calculated and compared with tolerable daily intake (TDI) index. The minimum and maximum concentration of cadmium was found in the sample with rice + milk formula (40.3 µg/kg) and infant food supplements containing wheat + milk (58.0 µgr/kg), respectively. The amount of cadmium, lead, manganese, molybdenum and nickel were estimated in the range of 40.3-58.0 ppb, 31.85 ppb, 2.3-4.9 ppm, 417.9-518.8 ppb and 4479.1-6415.0 ppb, respectively. In was concluded that the amount of toxic elements in infant foods marketed in Iran were found below the maximum limit

Investigation of Oxygen Transfer in a Two-phase Partition Stirred Tank Bioreactor in the Presence of Silicone Oil

A lab scale bioreactor was designed for treatment of waste gas containing benzene, toluene and xylene (BTX). Initial characterization of the bioreactor involved quantification of the oxygen transfer coefficient (kLa) as a function of some main operational variables. To evaluate and obtain optimal conditions in the 2.36 L bioreactor, the effect on oxygen transfer rate in several operational conditions including different proportions of organic phase (0, 5, 10, 20 and 30 %) in eleven agitation speeds (0 to 1000) and five aeration levels (1 to 5 L min–1) were tested. The results showed that the presence of silicone oil caused a reduction in the kLa of the aqueous phase for all the concentrations studied. Reduction of kLa due to the presence of silicone oil increased with augmentation of silicone oil fractions. The positive impact of agitation speed and gas flow on oxygen transfer was also observed in the presence of silicone oil, although their impact was somewhat reduced at higher silicone oil content. In addition, it was found that total power consumption declined with addition of different fractions of silicone oil to bioreactor aqueous phase. It was deduced that the most optimal silicone oil fraction and stirring rate are 10 % and 800 rpm respectively, from the viewpoint of oxygen transfer and total power consumption rate. Empirical correlations for the oxygen transfer rate in the bioreactor with the presence of different fractions of silicone oil revealed that the experimental kLa lay within the values predicted. Variations pattern in exponents of correlations showed that addition of silicone oil up to 10 % improves the superficial gas velocity that leads to enhanced kLa of oxygen and higher proportion of silicone oil, which may have negative effect