The effects of biological pretreatment on the rubberwood (Hevea brasiliensis), was evaluated after cultivation of white rot fungi Ceriporiopsis subvermispora, Trametes versicolor, and a mixed culture of C. subvermispora and T. versicolor. The analysis of chemical compositions indicated that C. subvermispora had greater selectivity for lignin degradation with the highest lignin and hemicellulose loss at 45.06% and 42.08%, respectively, and lowest cellulose loss (9.50%) after 90 days among the tested samples. X-ray analysis showed that pretreated samples had a higher crystallinity than untreated samples. The sample pretreated by C. subvermispora presented the highest crystallinity of all the samples which might be caused by the selective degradation of amorphous components. Fourier transform infrared (FT-IR) spectroscopy demonstrated that the content of lignin and hemicellulose decreased during the biological pretreatment process. A study on hydrolysis of rubberwood treated with C. subvermispora, T. versicolor, and mixed culture for 90 days resulted in an increased sugar yield of about 27.67%, 16.23%, and 14.20%, respectively, as compared with untreated rubberwood (2.88%). The results obtained demonstrate that rubberwood is a potential raw material for industrial applications and white rot fungus C. subevermispora provides an effective method for improving the enzymatic hydrolysis of rubberwood.

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In this study, lignin was isolated from rubber wood by means of ionic liquid (1,3-dimethylimidazolium methylsulfate). The optimum parameters to isolate lignin were investigated which include the concentrations of ionic liquid (0.1, 0.2, 0.3, 0.4, 0.5 moles), isolation durations (30, 60, 90, 120, 150 minutes), and isolation temperatures (25, 40, 60, 80, 100°C). The optimum parameters for lignin isolation are 0.5 moles concentration, 120 minutes and 100ºC. Lignin could be isolated from rubber wood up to 13.03wt.% by ionic liquid however, in comparison with acid and alkaline isolation, they give better yields than ionic liquid which 22.15wt.% and 18.56wt.% of lignin, respectively. Lignin preliminary structures isolated by ionic liquid have been confirmed based on Fourier transform infrared (FTIR) results. From these results, isolated lignin by ionic liquid provides lignin without other related isolative. Apart from that, ionic liquid also could be recycled up to three times compared to acid and alkaline isolation methods.

Palm-based esters, synthesized through enzymatic transesterification of palm oil fractions with oleyl alcohol have potential application in pharmaceutical formulations. The phase behaviour of palm-based esters containing ibuprofen with surfactant of different HLB values was investigated for topical delivery system. The surfactants were Tween 85, Tween 60 and Tween 80, and the palm-based esters were palm oil esters (POEs) and palm kernel oil esters (PKOEs). Ternary phase diagrams of palm-based esters: Ibuprofen/surfactant/water systems were constructed. Three distinct regions were observed in the phase diagrams; isotropic liquid region, L 1 , liquid crystalline region, L c and multiphase region, M. Nanoemulsions were prepared spontaneously by the addition of water to oil:ibuprofen/surfactant mixtures based on the ternary phase diagrams constructed. Formulations from the PKOEs:Ibuprofen/Tween 80/water systems were selected due to the presence of large isotropic liquid region, which suggested that this region was suitable to be used in producing nanoemulsions. Particle size analysis showed that the mean particle sizes of these formulations ranged from 10 nm to 70 nm. Zeta potential analysis for all formulations showed negative values from -4 to -8 mV. Stability studies showed that, after 4 h of stirring at room temperature (25°C), the formulations were stable under centrifugation test at 4000 rpm for 15 min. Stability under different storage temperature showed that at 25°C, the four formulations, F1, F2, F3 and F4 were stable with no phase separation for the duration of 1 month. However, when these formulations were stored at 45°C and 4°C, respectively, only F3 and F4 were observed to be stable. These two formulations have the potential to be used for topical delivery of ibuprofen.

Lipase-catalyzed production of triethanolamine-based esterquat by esterification of oleic acid (OA) with triethanolamine (TEA) in n-hexane was performed in 2 L stirred-tank reactor. A set of experiments was designed by central composite design to process modeling and statistically evaluate the findings. Five independent process variables, including enzyme amount, reaction time, reaction temperature, substrates molar ratio of OA to TEA, and agitation speed, were studied under the given conditions designed by Design Expert software. Experimental data were examined for normality test before data processing stage and skewness and kurtosis indices were determined. The mathematical model developed was found to be adequate and statistically accurate to predict the optimum conversion of product. Response surface methodology with central composite design gave the best performance in this study, and the methodology as a whole has been proven to be adequate for the design and optimization of the enzymatic process.

In this study, estimation capabilities of the artificial neural network (ANN) and the wavelet neural network (WNN) based on genetic algorithm were investigated in a synthesis process. An enzymatic reaction catalyzed by Novozym 435 was selected as the model synthesis process. The conversion of enzymatic reaction was investigated as a response of five independent variables; enzyme amount, reaction time, reaction temperature, substrates molar ratio and agitation speed in conjunction with an experimental design. After training of the artificial neurons in ANN and WNN, using the data of 30 experimental points, the products were used for estimation of the response of the 18 experimental points. Estimated responses were compared with the experimentally determined responses and prediction capabilities of ANN and WNN were determined. Performance assessment indicated that the WNN model possessed superior predictive ability than the ANN model, since a very close agreement between the experimental and the predicted values was obtained.

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