Optimization of sunflower oil transesterification process using sodium methoxide

Homogeneous base catalyst with high activity and stability for synthesis of dimethyl carbonate by transesterification†

In the synthesis of dimethyl carbonate (DMC) by transesterification, CH₃ONa has been commonly applied as a homogeneous catalyst due to its high catalytic activity, but its stability is unsatisfactory. Here, by studying the influence of ionic liquid base strength on transesterification, we prepared an organic base catalyst, potassium imidazole (KIm), with high catalytic activity and stability, which solved the problem of catalyst deactivation in transesterification. The results showed that when KIm was used in the synthesis of DMC from propylene carbonate (PC) and methanol (MeOH), the chemical equilibrium could be reached within 3 minutes and the yield of DMC reached 73.03%, indicating that KIm performed better in transesterification than the majority of previously reported catalysts. In addition, the activity of the catalyst had hardly decreased after ten cycles of reaction, which can well meet the requirements of industrial production.

A novel type of homogeneous catalyst KIm was developed and applied to the reaction of PC and MeOH to synthesize DMC.

Rhynchophorus palmarum (Linnaeus, 1758) (Coleoptera: Curculionidae): Guarani-Kaiowá indigenous knowledge and pharmacological activities

Zootherapy is a traditional secular practice among the Guarani-Kaiowá indigenous ethnic group living in Mato Grosso do Sul, Brazil. My people use the oil extracted from larvae of the snout beetle Rhynchophorus palmarum (Linnaeus, 1758) to treat and heal skin wounds and respiratory diseases. Based on this ethnopharmacological knowledge, the chemical composition and antioxidant, antimicrobial, and healing properties of R. palmarum larvae oil (RPLO) were investigated, as well as possible toxic effects, through in vitro and in vivo assays. The chemical composition of the RPLO was determined using gas chromatography coupled with mass spectrometry. The antioxidant activity of RPLO was investigated through the direct 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, and the antimicrobial activity was evaluated against Gram-positive and Gram-negative bacteria that are pathogenic to humans. The healing properties of RPLO were investigated by performing a cell migration assay using human lung fibroblasts (MRC-5), and the toxicity was analyzed, in vivo, using a Caenorhabditis elegans model and MRC-5 cells, in vitro. RPLO contains 52.2% saturated fatty acids and 47.4% unsaturated fatty acids, with palmitic acid (42.7%) and oleic acid (40%) representing its major components, respectively. RPLO possesses direct antioxidant activity, with a half-maximal inhibitory concentration (IC50) of 46.15 mg.ml-1. The antimicrobial activity of RPLO was not observed at a concentration of 1% (v/v). RPLO did not alter the viability of MRC-5 cells and did not exert toxic effects on C. elegans. Furthermore, MRC-5 cells incubated with 0.5% RPLO showed a higher rate of cell migration than that of the control group, supporting its healing properties. Taken together, RPLO possesses direct antioxidant activity and the potential to aid in the healing process and is not toxic toward in vitro and in vivo models, corroborating the safe use of the oil in traditional Guarani-Kaiowá medicine.

Gas chromatography-mass spectrometry-based analytical strategies for fatty acid analysis in biological samples

Fatty acids play critical roles in biological systems. Imbalances in fatty acids are related to a variety of diseases, which makes the measurement of fatty acids in biological samples important. Many analytical strategies have been developed to investigate fatty acids in various biological samples. Due to the structural diversity of fatty acids, many factors need to be considered when developing analytical methods including extraction methods, derivatization methods, column selections, and internal standard selections. This review focused on gas chromatography-mass spectrometry (GC-MS)-based methods. We reviewed several commonly used fatty acid extraction approaches, including liquid-liquid extraction and solid-phase microextraction. Moreover, both acid and base derivatization methods and other specially designed methods were comprehensively reviewed, and their strengths and limitations were discussed. Having good separation efficiency is essential to building an accurate and reliable GC-MS platform for fatty acid analysis. We reviewed the separation performance of different columns and discussed the application of multidimensional GC for improving separations. The selection of internal standards was also discussed. In the final section, we introduced several biomedical studies that measured fatty acid levels in different sample matrices and provided hints on the relationships between fatty acid imbalances and diseases.

Modeling and optimization of lucky nut biodiesel production from lucky nut seed by pearl spar catalysed transesterification

In 2015, the Worldatlas recorded 50 countries whose source of income is fossil fuel and its derivatives. Surprisingly, these countries solely depend on this source of energy up to 100% (Omar, Qatar, Kuwait and Saudi Arabia) because of technology improvement. It's so sadden that apart from its adverse effect on the economics of the countries, fossil fuels harmful effects on the universe cannot be overlooked. Meanwhile, the use of renewable energy as a replacement for fossil fuel and its derivatives are faced by the high oil price, high cost of investment for alternative energy, and unfathomed electricity prices. This research work evaluates desirability of making use of alternative source of energy sources by making use of biomass oil over the use of fossil fuel and its derivatives for electricity generation.

Lucky nut is an agricultural non edible seed that was employed as raw material for biofuel production. The non-edible oil was extracted from the seeds and the oil was further converted to Lucky nut biofuel via a heterogeneous based catalyst produced from calcinated pearl spar. For modelling and optimization, design expert coupled with genetic algorithms were used to generate experimental designs so as to correlate the variable factors considered for production.

The extraction of Lucky nut seed revealed the optimum production yield of 50.80% (v/v) and the oil is highly unsaturated. Energy Dispersive X-ray Fluorescence Spectrophotometer analyses and scanning electron microscope (SEM) of the calcined catalyst obtained from pearl spar showed the major component found in the pearl spar was K with relative abundance of 58.48%, which favoured the yield of Lucky nut biodiesel (91.00% (v/v)). Based on predicted values, the optimum validated Lucky nut biodiesel by RSMED and ANNED were 89.68% (v/v) and 92.87% (v/v), respectively. Produced properties of biofuel conformed to the biofuel standard.

The study concluded that Lucky nut seed is a good source of oil, and its transformation to alternative fuel via a using calcined catalyst proved its fitness as a replacement for fossil fuel.

Optimization of solvent extraction of shea butter (Vitellaria paradoxa) using response surface methodology and its characterization

Shea butter (SB) was extracted from its kernel by using n-hexane as solvent in an optimization study. This was to determine the optima operating variables that would give optimum yield of SB and to study the effect of solvent on the physico-chemical properties and chemical composition of SB extracted using n-hexane. A Box-behnken response surface methodology (RSM) was used for the optimization study while statistical analysis using ANOVA was used to test the significance of the variables for the process. The variables considered for this study were: sample weight (g), solvent volume (ml) and extraction time (min). The physico-chemical properties of SB extracted were determined using standard methods and Fourier Transform Infrared Spectroscopy (FTIR) for the chemical composition. The results of RSM analysis showed that the three variables investigated have significant effect (p < 0.05) on the %yield of SB, with R(2) - 0.8989 which showed good fitness of a second-order model. Based on this model, optima operating variables for the extraction process were established as: sample weight of 30.04 g, solvent volume of 346.04 ml and extraction time of 40 min, which gave 66.90 % yield of SB. Furthermore, the result of the physico-chemical properties obtained for the shea butter extracted using traditional method (SBT) showed that it is a more suitable raw material for food, biodiesel production, cosmetics, medicinal and pharmaceutical purposes than shea butter extracted using solvent extraction method (SBS). Fourier Transform Infrared Spectroscopy (FTIR) results obtained for the two samples were similar to what was obtainable from other vegetable oil.

Comparison of two derivatization methods for the analysis of fatty acids and trans fatty acids in bakery products using gas chromatography

Two different procedures for the methylation of fatty acids (FAs) and trans fatty acids (TFAs) in food fats were compared using gas chromatography (GC-FID). The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl) and the base-catalyzed followed by (trimethylsilyl)diazomethane (TMS-DM) method were used to prepare FA methyl esters (FAMEs) from lipids extracted from food products. In general, both methods were suitable for the determination of cis/trans FAs. The correlation coefficients (r) between the methods were relatively small (ranging from 0.86 to 0.99) and had a high level of agreement for the most abundant FAs. The significant differences (P = 0.05) can be observed for unsaturated FAs (UFAs), specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R) and higher variation (from 84% to 112%), especially for UFAs. The TMS-DM method had higher R values, less variation (from 90% to 106%), and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp.) than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of rich cis/trans UFA samples.

Statistical optimization of process parameters for lipase-catalyzed synthesis of triethanolamine-based esterquats using response surface methodology in 2-liter bioreactor

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.