Melting and crystallisation behaviour of soybean oil in blend with palm oil-based diacylglycerol

In the present work, the physicochemical properties namely fatty acid composition (FAC), iodine value (IV), acylglycerol content and thermal profiles of palm-based diacylglycerol (PDAG) in blend with soybean oil (SBO) at different concentrations (0-100 wt %) were evaluated. The Fourier-transform infrared spectroscopy (FTIR) spectra were determined at mid-infrared region to assign the functional groups. SBO exhibited the same absorption bands as PDAG except at wavelength of 1711, 1450, 1359, 850 and 779 cm-1. This phenomenon indicated that the absorption frequency of the binary mixtures greatly depended on the composition of oil samples. IV of the oil blends was found to decrease from 131.09 ± 0.88 I2/100 g to 51.55 ± 0.60 I2/100 g with increasing PDAG concentrations due to the reduced degree of unsaturation. Generally, binary blends with an increasing PDAG concentration showed a decrease in linoleic acid (C18:2) as well as increase in oleic acid (C18:1) and palmitic acid (C16:0) contents. The DAG content for all the blends increased from 5.15 ± 1.40% to 87.80 ± 0.33% and TAG content decreased from 94.85 ± 1.40% to 12.20 ± 0.33% in tandem with increasing PDAG content. Incorporation of PDAG into SBO significantly affected the crystallisation and melting profiles of SBO

Self built of laboratory scale supercritical anti solvent system

Supercritical fluid (SCF) particles formation technique gained a significant attention mainly in the pharmaceutical, cosmetic and paints. However, the scarcity of information on the design and process for this type of laboratory scale equipment is a significant drawback to the technological progress. Therefore, the purpose of this study was to design and build a laboratory supercritical anti solvent (SAS) system for producing microparticles and microcapsules of acetaminophen. The operating conditions of the constructed system affected the yield. The optimum operating conditions were then determined as: 110 bars, 35° C, 35 mg/ml of polymer concentration and 1.75 ml/min of feed flow rate. The microparticles and microcapsules were characterized on its morphology (scanning electron microscopy), size distribution (particle size analyzer), thermal properties (thermo gravimetetric analyzer) and crystallographic (X-ray powder diffraction). The in vitro drug released of the microparticles and microcapsules were also investigated. The results revealed a more homogenous microparticle size distribution, a change in the crystalinity and maintained of drug thermal stability after the SAS process. Furthermore, the microcapsules prolong the drug released significantly in the in vitro study

The effect of buoyancy force in computational fluid dynamics simulation of a two-dimensional continuous ohmic heating process

Problem statement: Earlier work on ohmic heating technique focused on viscous food and foods containing solid particles. In this study, the use of ohmic heating on sterilization of guava juice is carried out. Computational fluid dynamics is used to model and simulate the system. Approach: Investigate the buoyancy effect on the CFD simulation of continuous ohmic heating systems of fluid foods. A two-dimensional model describing the flow, temperature and electric field distribution of non-Newtonian power law guava juice fluid in a cylindrical continuous ohmic heating cell was developed. The electrical conductivity, thermo physical and rheological properties of the fluid was temperature dependent. The numerical simulation was carried out using FLUENT 6.1 software package. A user defined functions available in FLUENT 6.1 was employed for the electric field equation. The heating cell used consisted of a cylindrical tube of diameter 0.05 m, height 0.50 m and having three collinear electrodes of 0.02 m width separated by a distance of 0.22 m. The sample was subjected to zero voltage at the top and bottom of electrodes while electrical potential of 90 volts (AC 50-60 Hz) was set at the middle electrode. The inlet velocity is 0.003 m sec1 and the temperature is in the range of 30-90°C. Results: The simulation was carried with and without buoyancy driven force effect. The ohmic heating was successfully simulated using CFD and the results shows that the buoyancy has a strong effect in temperature profiles and flow pattern of the collinear electrodes configuration ohmic heating. A more uniform velocity and temperature profiles were obtained with the buoyancy effect included. Conclusion: For accurate results, the inclusion of buoyancy effect into the CFD simulation is important