Lipase-catalyzed transesterification of medium-long-medium structured lipid (MLM-SL) using palm olein and tricaprylin in packed-bed reactor (PBR)

Lipase-catalyzed transesterification between refined bleached deodorized palm olein (RBDO) and tricaprylin to produce medium-long-medium structured lipid (MLM-SL) in a packed bed reactor (PBR) has been investigated. A specific sn-1,3 commercial Lipozyme TL IM was used as biocatalyst. Within this study, the progress of transesterification was monitored especially for triacylglycerol (TAG) formation with equivalent carbon number (ECN) of 32, presumably 1,3-dicapryoyl-2-oleoyl-sn-glycerol (COC). Transesterification conditions investigated were residence times (i.e., 15, 30, and 60 min) and enzyme loadings (2.0 and 4.5 g). The highest yield of ECN 32 (13%) and transesterification degree (71%) were obtained at residence time of 15 mins for both enzyme loadings. Longer residence time seemed to facilitate lipid hydrolysis over transesterification. This was indicated by the number of peaks appearing in the high-performance liquid chromatography (HPLC) chromatograms and the reduction of fat slip melting point (SMP). Additionally, the highest productivity was obtained at 2.0 g enzyme loading. Conclusively, this study has demonstrated the potential use of packed-bed reactor with immobilized Lipozyme TL IM for continuous synthesis of MLM-SLs especially TAG with ECN32.

The synthesis of medium-long-medium structured lipid (MLM-SL) by lipase-catalyzed transesterification using palm olein and tricaprylin in packed-bed reactor (PBR)

Lipase-catalyzed transesterification between refined bleached deodorized palm olein (RBDO) and tricaprylin to produce medium-long-medium structured lipid (MLM-SL) in a packed bed reactor has been investigated. A specific sn -1,3 commercial Lipozyme TL IM was used as biocatalyst. Within this study, the progress of transesterification was monitored especially for triacylglycerol (TAG) formation with equivalent carbon number (ECN) of 32, presumably 1,3-dicapryoyl-2-oleoyl- sn -glycerol (COC). Transesterification conditions investigated were residence times ( i.e ., 15, 30, and 60 min) and enzyme loadings (2 and 4.5 g). The highest yield of ECN 32 (13%) and transesterification degree (71%) were obtained at residence time of 15 mins for both enzyme loadings. Longer residence time seemed to facilitate lipid hydrolysis over transesterification. This was indicated by the number of peaks appearing in the high-performance liquid chromatography (HPLC) chromatograms and the reduction of of fat slip melting point (SMP). Additionally, at 4.5 enzyme loading the highest productivity was obtained for one-cycle reaction. Conclusively, this study has demonstrated the potential use of packed-bed reactor with immobilized Lipozyme TL IM for continuous synthesis of MLM-SLs especially TAG ECN32.

Physicochemical Properties of Enzymatically Synthesised Medium-Chain Triacylglycerols-based Enhancer Cream

Structured lipids (SLs) containing medium-chain triacylglycerols (MCTs) were produced by lipase catalysed acidolysis of both octanoic acid and the virgin coconut oil (VCO). The production of SLs, namely structured virgin coconut oil (SVCO), was previously optimised using the central composite design (CCD) based on the percentage of octanoic acid incorporated in the reaction products. The fatty acids and triacylglycerols composition and their corresponding rheological properties of the formulated SVCO incorporated α-tocopherol cream were also determined. The parameters that were suggested for the highest incorporation of octanoic acid (68.07%) are octanoic acid to VCO ratio of 1.70 (w/w); an enzyme load of 22.60%; at 63.4°C; a water content of 3.53%; and at 96 h. The amount of octanoic acid (carbon-8), the medium-chain fatty acids present in the structured lipid after enzymatic esterification was increased to 60.1% as compared to the natural VCO with only contains 5.45%. Based on the calculated equivalent carbon number (ECN), the most probable MCTs found in the SVCO were CpCpCp, CpCCp, and CpLaCp. Based on the rheological analysis, the SVCO creams were less viscoelastic as compared to the VCO. It shows that the decrease of the saturated fatty acids composition (carbon-12, 14, and 16) in the SVCO creams had significantly decreased the elasticity of the cream

Physicochemical and biochemical characterizations of some Tunisian seed oils

Four Tunisian vegetable oils extracted from seeds (Nigella sativa, Opuntia ficus indica, Pistacia lentiscus and Hibiscus sabdariffa) have been characterized in this study. The following parameters were determined: acidity, peroxide value, saponification value, specific extinction coefficients K232, K270, chlorophylls and carotenoids content. The triglyceride and tocopherol compositions of the oils were determined using reversed phase high performance liquid chromatography with diode array detection (HPLC-DAD) and the fatty acids (FA) and phytosterol compositions were determined using a gas chromatography (GC) with a flame ionization detector (FID). Polyunsaturated fatty acids were predominant in all tested samples except in Pistacia lentiscus oil where monounsaturated fatty acids were predominant. Major FA were linoleic and oleic acids. β-sitosterol was the most abundant phytosterol. All samples had high content of TAGs with an equivalent carbon number of 44, 46 and 48. Nigella sativa oil had the highest content of tocopherols.

Occurrence and sources of aliphatic hydrocarbons in anthropogenic impacted soils from petroleum tank-farms in the Niger Delta, Nigeria

The occurrence and compositional pattern of priority pollutants are vital in understanding the anthropogenic contributions, origin, and risks of these pollutants to the surrounding environment. Thus, the focus of this study was to determine the concentrations, compositional profiles, and sources of aliphatic hydrocarbons (AHCs) in anthropogenic impacted soils from petroleum tank-farms environment in the Niger Delta, Nigeria. Forty-five soil samples were collected from the vicinity of petroleum tank-farms at the top (0-15 cm), sub (15-30 cm), and bottom (30-45 cm) soil depths. The concentration of AHCs was determined using gas chromatography-mass spectrometer (GC-MS) after extraction by ultrasonication with hexane/dichloromethane and clean-up in silica gel/alumina packed column. The mean concentrations of AHCs in the samples ranged from 0.52 ± 0.90 to 35.26 ± 35.69 mg/kg. The AHCs results show that the equivalent carbon number index (ECn-) ECn-13-35 had the highest concentration when compared to ECn-8-12 and ECn-36-40. The linear regression and ANOVA indicate that there is no significant positive correlation between TOC and the total concentration of AHCs in the soil profiles, and a significant variation in AHCs levels between soil profiles respectively. Results also showed that soils from the tank-farms are moderately contaminated with AHCs when compared to the UNEP recommended limit. However, when compared to other regulatory thresholds, the observed concentrations of AHCs, human and environmental health risks are likely. Source apportionments depict that the principal sources of AHCs were petrogenic and plant diagenesis. Appropriate clean-up and mitigation measures and further study to determine the occurrence, composition, and exposure risks of other priority pollutants in water and sediment samples from the surrounding creeks should be determined.

Validation of a Method Based on Triglycerides for the Detection of Low Percentages of Hazelnut Oil in Olive Oil by Column Liquid Chromatography

The difference between theoretical and empirical triglyceride content is a powerful tool to detect the presence of any vegetable oil in olive oil. The current drawback of the method is the separation between equivalent carbon number ECN42 compounds, which affects the reliability of the method and, hence, its cutoff limit. The determination of the triglyceride profile by liquid chromatography using propionitrile as the mobile phase has recently been proposed to improve their quantification, together with a mathematical algorithm whose binary response determines the presence or absence of hazelnut oil. Twenty-one laboratories from 9 countries participated in an interlaboratory study to evaluate the performance characteristics of the whole analytical method. Participants analyzed 12 samples in duplicate, split into 3 intercomparison studies. Statistically significant differences due to the experimental conditions were found in some laboratories, which were detected as outliers by use of Cochran's and Grubbs' tests. The relative standard deviations (RSD) for repeatability and reproducibility were determined following the AOAC Guidelines for Collaborative Studies. The analytical properties of the method were determined by means of the sensitivity (0.86), selectivity (0.94), and reliability (72) for a cutoff limit of 8 (probability 94).