The synthesis of oxygenated fuel additives via solvent freebase-catalyzed etherification of glycerol is reported. The products of glycerol etherification arediglycerol (DG) and triglycerol (TG) with DG being the favorable one. The catalytic activity of different homogeneous alkali catalysts (LiOH, NaOH, KOH and Na(2)CO(3)) was investigated during the glycerol etherification process. LiOH exhibited an excellent catalytic activity during this reaction, indicated by the complete glycerol conversion with a corresponding selectivity of 33% toward DG. The best reaction conditions were a reaction temperature of 240°C, a catalyst/glycerol mass ratio of 0.02 and a reaction time of 6h. The influences of various reaction variables such as nature of the catalyst, catalyst loading, reaction time and reaction temperature on glycerol etherification were elucidated. Industrially, the findings attained in this study might contribute towards promoting the biodiesel industry through utilization of its by-products.
Diacylglycerol (DAG), which has health-enhancing properties, is sometimes added to bakery shortening to produce baked products with enhanced physical functionality. Nevertheless, the quantity present is often too little to exert any positive healthful effects. This research aimed to produce bakery shortenings containing significant amounts of palm diacyglycerol (PDG). Physicochemical, textural and viscoelastic properties of the PDG bakery shortenings during 3 months storage were evaluated and compared with those of commercial bakery shortening (CS).
This paper discusses a rapid GC-FID technique for the simultaneous quantitative analysis of FFA, MAG, DAG, TAG, sterols, and squalene in vegetable oils, with special reference to palm oil. The FFA content determined had a lower SE compared with a conventional titrimetric method. Squalene and individual sterols, consisting of beta-sitosterol, stigmasterol, campesterol, and cholesterol, were accurately quantified without any losses. This was achieved through elimination of tedious conventional sample pretreatments, such as saponification and preparative TLC. With this technique, the separation of individual MAG, consisting of 16:0, 18:0, and 18:1 FA, and the DAG species, consisting of the 1,2(2,3)- and 1,3-positions, was sufficient to enable their quantification. This technique enabled the TAG to be determined according to their carbon numbers in the range of C44 to C56. Comparisons were made with conventional methods, and the results were in good agreement with those reported in the literature.
This paper examines the processing steps of extracting palm oil from fresh fruit bunches in a way that may impact on the formation of chloropropandiol fatty esters (3-MCPD esters), particularly during refining. Diacylglycerols (DAGs) do not appear to be a critical factor when crude palm oils are extracted from various qualities of fruit bunches. Highly hydrolysed oils, in spite of the high free fatty acid (FFA) contents, did not show exceptionally high DAGs, and the oils did not display a higher formation of 3-MCPD esters upon heat treatment. However, acidity measured in terms of pH appears to have a strong impact on 3-MCPD ester formation in the crude oil when heated at high temperatures. The differences in the extraction process of crude palm oil from current commercial processes and that from a modified experimental process showed clearly the effect of acidity of the oil on the formation of 3-MCPD esters. This paper concludes that the washing or dilution step in palm oil mills removes the acidity of the vegetative materials and that a well-optimised dilution/washing step in the extraction process will play an important role in reducing formation of 3-MCPD esters in crude palm oil upon further heat processing.
Protein drugs may encounter conformational perturbations during the formulation processing of lipid-based solid dosage forms. In aqueous protein solutions, attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy can investigate these conformational changes following the subtraction of spectral interference of solvent with protein amide I bands. However, in solid dosage forms, the possible spectral contribution of lipid carriers to protein amide I band may be an obstacle to determine conformational alterations. The objective of this study was to develop an ATR FT-IR spectroscopic method for the analysis of protein secondary structure embedded in solid lipid matrices. Bovine serum albumin (BSA) was chosen as a model protein, while Precirol AT05 (glycerol palmitostearate, melting point 58 ℃) was employed as the model lipid matrix. Bovine serum albumin was incorporated into lipid using physical mixing, melting and mixing, or wet granulation mixing methods. Attenuated total reflection FT-IR spectroscopy and size exclusion chromatography (SEC) were performed for the analysis of BSA secondary structure and its dissolution in aqueous media, respectively. The results showed significant interference of Precirol ATO5 with BSA amide I band which was subtracted up to 90% w/w lipid content to analyze BSA secondary structure. In addition, ATR FT-IR spectroscopy also detected thermally denatured BSA solid alone and in the presence of lipid matrix indicating its suitability for the detection of denatured protein solids in lipid matrices. Despite being in the solid state, conformational changes occurred to BSA upon incorporation into solid lipid matrices. However, the extent of these conformational alterations was found to be dependent on the mixing method employed as indicated by area overlap calculations. For instance, the melting and mixing method imparted negligible effect on BSA secondary structure, whereas the wet granulation mixing method promoted more changes. Size exclusion chromatography analysis depicted the complete dissolution of BSA in the aqueous media employed in the wet granulation method. In conclusion, an ATR FT-IR spectroscopic method was successfully developed to investigate BSA secondary structure in solid lipid matrices following the subtraction of lipid spectral interference. The ATR FT-IR spectroscopy could further be applied to investigate the secondary structure perturbations of therapeutic proteins during their formulation development.
Palm pressed fiber (PPF) is a by-product from oil extraction of oil palm fruits. It has unique characteristics resulting from the combination of palm mesocarp fiber, kernel shell and crushed kernel. The present study on different extraction methods for PPF indicated that conventional hexane cold extraction would be the more preferable method compared to soxhlet and reflux method due to the yield recovered (4.35%) and diacylglycerol (19.93% ± 0.07) obtained. Acylglycerol composition using cold extraction gave high Diaclyglycerol and Triacylglycerol (67.04% ± 0.05) with reasonable amount of Monoaclyglycerol / Free Fatty Acid (13.02% ± 0.02). Lauric acid which was not present in crude palm oil were found to be significant in PPF (5.89 to 9.09%), thus making this oil suitable for application in the food industry in products such as shortening and margarine.
The stability of refined, bleached, and deodorized palm olein (RBDPO) was studied under controlled heating conditions. RBDPO was heated continuously for 24 h at 160, 170, and 180 °C, with oil sampled at four hour intervals. Thermo-oxidative alterations were measured through various parameters, such as monomeric oxidized triacylglycerols (oxTAG), total polar compounds (TPC), polymerized triacylglycerols (PTG), oxidative stability, and fatty acid composition. After 24 h of heating, the TPC and triacylglycerol oligomers showed a linear increase with heating time at all heating temperatures. At the end of the heating study, more epoxy acids were formed than keto and hydroxy acids. Moreover, caprylic acid, which was not present in fresh oil, was formed in significant amounts. The increase in oxTAG was strongly correlated with the increase in the p-anisidine value and total oxidation value. The decreases in diacylglycerol and free fatty acids were strongly correlated with an increase in PTG.
Approximately 900 tonne of crude palm oil (CPO) underwent washing using 5 to 10% hot water (90 to 95°C) at a palm oil mill. The aim of the CPO washing was to eliminate and/or reduce total chlorine content present in the conventional CPO, as it is known as the main precursor for the formation of 3-monochloropropane-1, 2-diol esters (3-MCPDE). By a simple hot water washing, more than 85% of the total chlorine was removed. However, washing did not have significant (p > 0.05) effect on other oil quality parameters such as the deterioration of bleachability index (DOBI), free fatty acid (FFA) content and diacylglycerol (DAG) content of the oil. The latter has been established as the main precursor for glycidyl esters (GE) formation. The treated CPO was then transported using tankers and further refined at a commercial refinery. Refining of washed CPO resulted in significantly (p < 0.05) lower formation of 3-MCPDE, but GE content remained slightly high. Post-treatment of refined oil significantly reduced the GE content (p < 0.05) to an acceptable level whilst almost maintaining the low 3-MCPDE level. The study has proven that water washing of CPO prior to refining and subsequent post-refining is so far the most effective way to produce good quality refined oil with considerably low 3-MCPDE and GE contents. Dry fractionation of refined palm oil showed these contaminants partitioned more into the liquid olein fraction compared to the stearin fraction.
This study was conducted to investigate the influence of formulation development methods on the stability (secondary structure, aggregation, and biological activity) of protein drugs embedded in lipid matrices. Catalase, horseradish peroxidase, and α-chymotrypsin were employed as model proteins, while Precirol® AT05 (glyceryl palmitostearate) was used as lipid matrix. Protein-loaded lipid matrices were prepared using melting and mixing and wet granulation methods. Attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy, size exclusion chromatography (SEC) and biological activity analyses were performed. ATR FT-IR analysis indicated significant interference of the lipid with the protein amide-I band, which was eliminated using spectral subtraction. Wet granulation method induced more changes in protein secondary structure compared to melting and mixing method. SEC analysis gave evidence of protein aggregation for catalase upon adopting the wet granulation method. The biological activity of catalase was found to reduce significantly than other two proteins upon using wet granulation method, which might be ascribed to both secondary structure alterations and the formation of aggregates. Horseradish peroxidase and α-chymotrypsin did not form any soluble aggregates. In conclusion, melting and mixing method emerged as a better incorporation method compared to wet granulation because of better stability shown by the formulated proteins.
The objectives of this study were to develop and characterize itraconazole (ITZ)-loaded nanostructured lipid carriers (NLCs) and to study their potential for drug delivery into the brain. Precirol(®) ATO 5 and Transcutol(®) HP were selected as the lipid phase, and Tween(®) 80 and Solutol(®) HS15 as surfactants. The ITZ-NLCs were prepared by a hot and high-pressure homogenization method. The entrapment efficiency for the best formulation batch was analyzed using high-performance liquid chromatography and was found to be 70.5%±0.6%. The average size, zeta potential, and polydispersity index for the ITZ-NLCs used for animal studies were found to be 313.7±15.3 nm, -18.7±0.30 mV, and 0.562±0.070, respectively. Transmission electron microscopy confirmed that ITZ-NLCs were spherical in shape, with a size of less than 200 nm. Differential scanning calorimetry and X-ray diffractometry analysis showed that ITZ was encapsulated in the lipid matrix and present in the amorphous form. The in vitro release study showed that ITZ-NLCs achieved a sustained release, with cumulative release of 80.6%±5.3% up to 24 hours. An in vivo study showed that ITZ-NLCs could increase the ITZ concentration in the brain by almost twofold. These results suggest that ITZ-NLCs can be exploited as nanocarriers to achieve sustained release and brain-targeted delivery.
This study aims to identify potential phenolic compounds, terpenoids, and other phytochemicals, as well as fatty acid profile and peptides in Canarium odontophyllum (CO) oil and oleoresin, extracted using supercritical carbon dioxide. LC-ESI-MS was applied in separation and tentative identification of phytochemicals in CO oil and oleoresin. Based on the results, 11 common fatty acids and their isomers, monoglycerides, diglycerides, as well as other types of lipid, were tentatively identified in the CO oil and oleoresin. The identified fatty acids consisted of saturated fatty acids (C8-C16), monounsaturated fatty acids (C16:1 and C18:1), polyunsaturated fatty acids (C18:2, C18:3, C18:4, and C20:3), and other unclassified fatty acids. The tentatively identified phenolic compounds were phenolic acids, flavonoids, lignans, and a phenolic monoester. Triterpenes, sesquiterpenes, and apocarotenoids were the terpenoids found in CO oil and oleoresin. Besides these typical bioactives, some volatiles, aromatic compounds, peptides, and other known and unknown phytochemicals were also tentatively identified in the oil and oleoresin of CO. Some of these compounds are new compounds identified in CO oil and oleoresin, which are not found in many other fruit oils. Although CO oil and oleoresin contain a small number of phytochemicals, their contribution as antioxidants may prevent several diseases. In this study, we hypothesized that CO oleoresin contains certain types of fatty acids that render its semi-solid together with other chemical components which are not found in CO oil. This is the first study that tentatively identified fatty acids, peptides, and potential phytochemicals in CO oil and oleoresin using LC-ESI-MS.
During high-temperature refining of vegetable oils, 3-monochloropropanediol (3-MCPD) esters, possible carcinogens, are formed from acylglycerol in the presence of a chlorine source. To investigate organochlorine compounds in vegetable oils as possible precursors for 3-MCPD esters, we tested crude palm, soybean, rapeseed, sunflower, corn, coconut, and olive oils for the presence of organochlorine compounds. Having found them in all vegetable oils tested, we focused subsequent study on oil palm products. Analysis of the chlorine isotope mass pattern exhibited in high-resolution mass spectrometry enabled organochlorine compound identification in crude palm oils as constituents of wax esters, fatty acid, diacylglycerols, and sphingolipids, which are produced endogenously in oil palm mesocarp throughout ripening. Analysis of thermal decomposition and changes during refining suggested that these naturally present organochlorine compounds in palm oils and perhaps in other vegetable oils are precursors of 3-MCPD esters. Enrichment and dose-response showed a linear relationship to 3-MCPD ester formation and indicated that the sphingolipid-based organochlorine compounds are the most active precursors of 3-MCPD esters.