Effect of enzymatic transesterification with flaxseed oil on the high-melting glycerides of palm stearin and palm olein

The effects of enzymatic transesterification on the melting behavior of palm stearin and palm olein, each blended separately with flaxseed oil in the ratio of 90∶10 and catalyzed by various types of lipases, were studied. The commercial lipases used were Lipozyme IM, Novozyme 435, and myceliumbound lipases of Aspergillus flavus and A. oryzae. The slip melting point (SMP) of the palm stearin/flaxseed oil (PS/FS) mixture transesterified with lipases decreased, with the highest drop noted for the mixture transesterified with Lipozyme IM. However, when palm stearin was replaced with palm olein, the SMP of the palm olein/flaxseed oil (PO/FS) mixture increased, with the commercial lipases causing an increase of 41 to 48% compared to the nontransesterified material. As expected, the solid fat content (SFC) of the transesterified PS/FS was lower at all temperatures than that of the nontransesterified PS/FS sample. In contrast, all transesterified PO/FS increased in SFC, particularly at 10°C. Results from DSc and HPLC analyses showed that the high-melting glycerides, especially the tripalmitin of palm stearin, were hydrolyzed. Consequently, 1,3-dipalmitoylglycerol was found to accumulate in the mixture. There was no difference in the FA compositions between the transesterified and nontransesterified mixtures.     

Synthesis and characterization of CaFe2O4 nanoparticles via co-precipitation and auto-combustion methods

In this paper, the techniques for the synthesis of CaFe₂O₄ nanoparticles using the auto-combustion and co-precipitation methods are discussed. The effects of both methods on the microstructure and magnetic properties of the CaFe₂O₄ nanoparticles were compared. The CaFe₂O₄ powder was obtained after drying the synthesized sample via co-precipitation overnight in an oven at 80 °C. For auto-combustion method, the sol that was initially formed was gradually converted into a gel, which was then combusted at 250 °C. Finally, the CaFe₂O₄ nanoparticles were calcined at 550 °C. The different synthesis methods produced nanoparticles with different physical and magnetic properties in order to find an optimum size to be utilized for drug delivery applications. The results of the X-ray diffraction showed that both processes produced nanocrystals with an orthorhombic crystalline structure. It was noted from the measurements made with a transmission electron microscope (TEM) that the synthesis using the co-precipitation method produced nanoparticles with a size of about 10–20 nm, which was comparable with the size that was obtained when the auto-combustion method was used. The magnetic properties were investigated using a vibrating sample magnetometer (VSM), where the magnetic saturation (M_s) of CaFe₂O₄ for the sample synthesized using the co-precipitation method was 47.279 emu/g, which was higher than the magnetic saturation (M_s) of 31.10 emu/g obtained when the auto-combustion method was used. The hysteresis loops (Hc) for the samples were 17.380 G and 6.1672 G, respectively. Additionally, the elaborate properties mentioned above, such as the size and superparamagnetic properties of the synthesized CaFe₂O₄ nanoparticle size, were the characteristics required for drug delivery because the targeted therapy required nanoparticles with good magnetic properties, a suitable size, and which were non-toxic in order to have a potential application in targeted drug delivery systems.     

Characterization and Elemental Quantification of Natural Hydroxyapatite Produced from Cow Bone

The demand for hydroxyapatite (HA) is increasing annually due to the growing number of orthopedic patients, but it is a challenge to meet this growing demand without interfering with the integrity of the environment. Here, natural HA was produced from cow bone through ultrasound treatment followed by a calcination process at various temperatures. Characterization of the produced HA was performed by techniques such as thermogravimetric analysis, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction analysis. The elemental composition of the HA was quantified through X‐ray photoelectron spectroscopy, energy dispersive X‐ray spectroscopy, X‐ray fluorescence, as well as carbon, hydrogen, nitrogen, sulfur (CHNS) analysis. The results demonstrate that pure HA was produced after calcination at 950 °C, corresponding to pure HA phase.     

Epoxidized natural rubber–alumina nanoparticle composites: Optimization of mixer parameters via response surface methodology

Epoxidized natural rubber–alumina nanoparticle composites were prepared by melt compounding with an internal mixer for a constant filler loading of 10 phr. Mixer parameters such as the mixing temperature, mixing time, and rotor speed were screened and optimized with response surface methodology to maximize the impact strength. The parameters were selected as three independent variables and the impact strength (J/m) was selected as the response in a screening factor study. The mixing temperature and its interaction terms were identified as insignificant factors with a P value greater than 0.0500. The optimum calculated values of the tested variables (rotor speed and mixing time) for the maximum impact strength were found to be a rotor speed of 60 rpm and a mixing time of 6 min with a predicted impact strength of 208.88 J/m. These predicted optimum parameters were tested in real experiments. The final impact strength was found to be close to the predicted value of 215.84 J/m, with only a 3.33% deviation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Extraction and physicochemical properties of low free fatty acid crude palm oil

Response surface methodology was applied to optimize the pre-treatment of oil palm (Elaeis guineensis) fruit spikelets before oil extraction. The treatment applied was drying at different times and temperatures. The dried spikelets were then subjected to mechanical processes and crude oil was extracted. A central composite design was employed to study the responses, namely percentage of free fatty acids (FFA) and oil yield, and the optimum conditions for minimum FFA and maximum oil yield were identified from their respective contour plots. It was concluded that the pre-treatment should be carried out for 12.8 h at 66.8 °C. Under the optimum conditions, the corresponding response values for FFA and oil yield were 1% and 33.6%, respectively. Some of the physicochemical properties of the extracted oil were then determined. The low free fatty acid crude palm oil exhibited good physicochemical properties and could be useful for industrial applications.     

The application of ridge polynomial neural network to multi-step ahead financial time series prediction

Motivated by the slow learning properties of multilayer perceptrons (MLPs) which utilize computationally intensive training algorithms, such as the backpropagation learning algorithm, and can get trapped in local minima, this work deals with ridge polynomial neural networks (RPNN), which maintain fast learning properties and powerful mapping capabilities of single layer high order neural networks. The RPNN is constructed from a number of increasing orders of Pi–Sigma units, which are used to capture the underlying patterns in financial time series signals and to predict future trends in the financial market. In particular, this paper systematically investigates a method of pre-processing the financial signals in order to reduce the influence of their trends. The performance of the networks is benchmarked against the performance of MLPs, functional link neural networks (FLNN), and Pi–Sigma neural networks (PSNN). Simulation results clearly demonstrate that RPNNs generate higher profit returns with fast convergence on various noisy financial signals.     

Development of Pistachio (Pistacia vera L.) Spread

Pistachio nut (Pistacia vera L.) is one of the most delicious and nutritious nuts in the world. Pistachio spreads were developed using pistachio paste as the main component, icing sugar, soy protein isolate (SPI), and red palm oil (RPO), at different ratios. The highest mean scores of all the sensory attributes were depicted by spreads that were made without addition of SPI. It was found that the work of shear was 0 to 11.0 kg s for an acceptable spread. Sensory spreadability, overall texture, spreadability, and overall acceptability were negatively correlated (R > 0.83) with the work of shear of spreads. The findings indicated that the presence of RPO had a direct effect on the viscoelastic behavior of the pistachio spreads. The a values, which are related to the green color of the pistachio product ranged from 1.7 to 3.9 for spread without addition of RPO, and 4.0 to 5.3 in the presence of RPO. Practical Application The development of pistachio spread would potentially increase the food uses of pistachio and introduce consumers with a healthier snack food.     

Thermodynamic Parameters of Anionic Surfactant-Quaternary Phosphonium Bromides Systems at the Cloud Point

The thermodynamics of clouding in an anionic surfactant, sodium dodecyl sulfate (SDS) and quaternary phosphonium bromides systems in the presence of glycerol are reported. The standard Gibbs energy change of solubilization (Δ_sG°) for all of the additives was found to be negative. The standard enthalpy change (Δ_sH°) and the standard entropy change (TΔ_sS°) values were found to be negative as well as positive depending upon the type and nature of the additive. The results were explained on the basis of their nature, effect on the water structure, and solubilization of these additives either in the micellar or aqueous phase.