High Free Fatty Acid Content Research Articles

Chemical Characterization of the Oil Separated by Mechanical Pressing from Strychnos madagascariensis Dried Fruit Pulp Flour.

In Mozambique, rural communities produce flours from the dried pulp of Strychnos madagascariensis fruits. Owing to its high lipid content, the oil from this flour is frequently separated by pressing to be used as seasoning and medicine. Aiming to characterize this oil, flour samples (n = 24), dried at two different temperatures (55 °C and 65 °C), were collected from four local communities, together with a control sample prepared in the lab (50 °C). The resulting oil was fluid at room temperature, deep orange, and characterized by a high content of oleic acid (62–63%), followed by palmitic (20%) and linoleic (7%). It contained considerable amounts of tocols (25–34 mg/100 g) and carotenoids (8–10 mg/100 g), as well as sterols (431 ± 10 mg/100 g) and triterpenic alcohols (823 ± 4 mg/100 g mg/100 g). The overall composition was highly consistent between origins and temperatures, with only small statistically significant differences (p < 0.05), mostly between the community dried flours and control group. However, its high free fatty acid content (22–25%) reveals intensive enzymatic hydrolysis during the drying/fermentation steps, whose extension can be reduced by optimizing its technological process. Its chemical profile supports some of its folklore uses, revealing that it can be a promising source of edible oil, with health and technological potential that is worth optimizing and exploring.

Free fatty acids promote degranulation of azurophil granules in neutrophils by inducing production of NADPH oxidase–derived reactive oxygen species in cows with subclinical ketosis

Subclinical ketosis (SCK) in dairy cows, a common metabolic disorder during the peripartal period, is accompanied by systemic inflammation. Excessive release of azurophil granule (AG) contents during degranulation of polymorphonuclear neutrophils (PMN) could contribute to systemic inflammation in SCK cows. Although the increase in blood free fatty acids (FFA) in SCK cows may promote AG degranulation from PMN, the underlying mechanisms are unclear. Thirty multiparous cows (within 3 wk postpartum) with similar lactation numbers (median = 3, range = 2-4) and days in milk (median = 6, range = 3-15) were classified based on serum β-hydroxybutyrate (BHB) level as control (n = 15, BHB < 0.6 mM) or SCK (n = 15, 1.2 mM < BHB < 3.0 mM). Cows with SCK had greater levels of serum haptoglobin, serum amyloid A, IL-1β, IL-6, IL-8 and tumor necrosis factor-α. These proinflammatory factors had strong positive correlations with myeloperoxidase (MPO), a marker protein of PMN AG, whose content was greater in the serum of SCK cows. Both the number of AG and the protein abundance of MPO were lower in PMN isolated from SCK cows. Additionally, we found a greater ratio of blood CH138A+/CD63high cells and greater mean fluorescence intensity of CD63 on the PMN membrane, further confirming the greater degree of AG degranulation in cows with SCK. In vitro FFA dose response (0, 0.3, 0.6, 1.2, and 2.4 mM for 4 h) and time course (0, 0.5, 1, 2, and 4 h with 0.6 mM) experiments were performed on PMN isolated from control cows. The increase in MPO content in extracellular supernatant resulting from those experiments led to the selection of 0.6 mM FFA for 1 h duration as conditions for subsequent studies. After FFA treatment, release of intracellular MPO was increased along with increased levels of CD63 mean fluorescence intensity on the PMN membrane, confirming that FFA promoted degranulation of AG. In addition, FFA treatment increased reactive oxygen species (ROS) production by PMN, an effect that was attenuated by incubation with diphenyleneiodonium chloride (DPI), a NADPH oxidase-derived ROS inhibitor. The mitochondrial-derived ROS inhibitor carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP) did not affect ROS in response to FFA treatment. Treatment with FFA increased p47 phosphorylation and mRNA abundance of NCF1, NCF2, and CYBB in PMN. Furthermore, DPI, but not FCCP, dampened the degranulation of PMN AG induced by FFA in vitro. These data suggested that the degranulation of AG in PMN induced by FFA was mediated by NADPH oxidase-derived ROS. As verified ex vivo, PMN from SCK cows had greater levels of ROS, phosphorylation of p47, and mRNA abundance of NCF1, NCF2, and CYBB. Overall, the present study revealed that high blood concentrations of FFA in SCK cows induce the production of NADPH oxidase-derived ROS, thereby promoting degranulation of AG in PMN. The stimulatory effect of FFA on the release of AG content during degranulation, especially MPO, provides a new insight into the systemic inflammation experienced by peripartal cows with SCK.

Various Pre-Treatment Methods to Reduce Free Fatty Acid Content in Non-Edible Vegetable Oils for Biodiesel Production

In this work, the efforts were made to reduce high free fatty acid (FFA) content in non-edible karanja and jatropha vegetable oils below 1 mg KOH/g. The process was optimized in terms of amount of sulphuric acid used in pre-treatment of the studied non-edible oils. Various adsorbents like activated carbon, alumina, alumina-silica, calcined alumina and calcined alumina-silica exhibited significant removal of FFA in a single-stage filtration process. Pre-treatment of test oil with calcined alumina-silica as adsorbent was found to be the most appropriate for the removal of free fatty acids. Ultraviolet-visible spectroscopy (UV) analysis showed that the original composition of test oil was not changed after the pre-treatment process.

Modeling and optimization of two-step shea butter oil biodiesel synthesis using snail shells as heterogeneous base catalysts

Shea butter oil (SBO) is underutilized in the biodiesel production industry in Nigeria because of its high free fatty acid (FFA) content, which reduces its biodiesel yield.

Production and emission evaluation of neem biodiesel blends in a single cylinder diesel engine

Biodiesel made from edible and non-edible vegetable oils, waste cooking oils, and animal fats is gaining popularity these days due to its renewable nature and environmental friendliness. As a result, several nations are switching to biodiesel production from plant oils such as maize, soy bean, canola, sunflower, palm, and others. However, these oils are out of reach for developing nations like India, since they may result in a lack of food-grade oil as well as a significant increase in gasoline prices. In this study, we used domestic non-edible neem oil to produce biodiesel, and to determine the best biodiesel blend for future fuel without compromising air quality. Using an Acid and Base catalyst, unprocessed neem oil with a high FFA (Free Fatty Acid) content was successfully transformed into pure biodiesel. As a result, according to this study, using 20% neem biodiesel will reduce the consumption of petroleum diesel while having no negative impact on the environment.

Gene cascade analysis in human granulosa tumor cells (KGN) following exposure to high levels of free fatty acids and insulin

Maternal metabolic disorders such as obesity and diabetes are detrimental factors that compromise fertility and the success rates of medically assisted procreation procedures. During metabolic stress, adipose tissue is more likely to release free fatty acids (FFA) in the serum resulting in an increase of FFA levels not only in blood, but also in follicular fluid (FF). In humans, high concentrations of palmitic acid and stearic acid reduced granulosa cell survival and were associated with poor cumulus-oocyte complex (COC) morphology. Obesity and high levels of circulating FFA were also causatively linked to hampered insulin sensitivity in cells and compensatory hyperinsulinemia. To provide a global picture of the principal upstream signaling pathways and genomic mechanisms involved in this metabolic context, human granulosa-like tumor cells (KGN) were treated with a combination of palmitic acid, oleic acid, and stearic acid at the higher physiological concentrations found in the follicular fluid of women with a higher body mass index (BMI) (≥ 30.0 kg/m2). We also tested a high concentration of insulin alone and in combination with high concentrations of fatty acids. Transcription analysis by RNA-seq with a cut off for fold change of 1.5 and p-value 0.05 resulted in thousands of differentially expressed genes for each treatment. Using analysis software such as Ingenuity Pathway Analysis (IPA), we were able to establish that high concentrations of FFA affected the expression of genes mainly related to glucose and insulin homoeostasis, fatty acid metabolism, as well as steroidogenesis and granulosa cell differentiation processes. The combination of insulin and high concentrations of FFA affected signaling pathways related to apoptosis, inflammation, and oxidative stress. Taken together, our results provided new information on the mechanisms that might be involved in human granulosa cells exposed to high concentrations of FFA and insulin in the contexts of metabolism disorders.

Biodiesel Production from Crude Palm Oil under Different Free Fatty Acid Content using Eversa Transform® 2.0 Enzyme

Low-cost yet viable feedstock, i.e., crude palm oil (CPO) is one of the potential sources to be utilized in the biodiesel industry. However, CPO mainly contains a high free fatty acid (FFA) content. One of the promising methods to treat feedstock containing high FFA such as CPO is an enzyme-catalyzed transesterification owing to no sensitivity to the presence of FFA. Hence, this study aims to investigate biodiesel production from CPO under different FFA content using enzyme-catalyzed transesterification. Eversa Transform® 2.0 lipase which is a low-cost enzyme was used as a liquid enzyme. Experiments were conducted by changing the temperature (30–60 °C), the methanol-to-CPO molar ratio (3:1–8:1), and enzyme concentration (0.1–0.4 wt%), and. Intriguingly, the higher the FFA content of CPO, the higher the biodiesel yield. The result showed that biodiesel yield as high as 97.91% could be attained at a milder temperature of 40 °C, CPO with FFA content of 19.33%, and methanol-to-CPO molar ratio of 7:1.

Optimization of the enzymatic butanolysis of jatropha oil for biodiesel production using Eversa

AbstractThe use of non‐edible oils for energy production is attracting increasing attention, with a particular focus on those oils that can be produced from plants growing in non‐arable areas. Among the possible alternatives, oils with high free fatty acid content, such as jatropha, have shown great potential. The optimization of jatropha oil in the presence of a bio‐based alcohol (butanol) was investigated for the production of biodiesel using a commercial enzyme (Eversa from Novozymes). The optimization was conducted by changing the reaction temperature and the amount of catalyst, with a 6:1 butanol/oil molar ratio, while the reaction time was set to 60 min. The optimal result was found at the highest reaction temperature (42 °C) and the highest catalyst amount (9.79%), with a biodiesel yield of 83%. A second optimization was conducted, allowing the time to run for up to 8 h. Here the final biodiesel produced was in line with the EU14214 standards, fulfilling all the requirements with the exception of the requirement for oxidation stability. In addition to fulfilling most of the EU14214 standards, the cost of this new enzyme is lower than that of other commercial alternatives. Results show that biodiesel produced using butanol as alcohol in the transesterification process improved cold flow properties in terms of cloud point (CP), pour point (PP), and cold filter plugging point (CFPP). © 2021 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley &amp; Sons Ltd.

Production of sustainable two-stroke engine biolubricant ester base oil from palm fatty acid distillate

In this study, palm fatty acid distillate (PFAD) was selected as the feedstock for biolubricant base oil production in two-stroke engine oils’ formulation. PFAD is a low-cost palm refinery by-product with a high free fatty acid (FFA) content (85%). The esterification of PFAD with neopentyl glycol (NPG) was conducted in the presence of a solid acid catalyst (SO42-/Fe2O3/Al2O3) to produce PFAD-NPG ester. Optimization profile indicated that PFAD conversion and PFAD-NPG ester yield were 84% and 82%, respectively, under optimum reaction conditions of 180 °C, 4 h, 2.0 wt% SO42-/Fe2O3/Al2O3 catalyst loading and a 2:1 PFAD to NPG molar ratio. The physicochemical properties of the base oil successfully comply with the Japanese Automotive Standards Organization (JASO) M345:2018 requirements for two-stroke oils in terms of sulfated ash content, kinematic viscosity at 100 °C and flash point. In addition, reusability of solid acid catalyst, SO42-/Fe2O3/Al2O3 was investigated, where PFAD conversion and PFAD-NPG ester yield were found to be excellent at 81% and 80%, respectively, which showed that the catalyst had good consistency after 5 cycles.

Postpartum cows showed high oocyte triacylglycerols concurrently with high plasma free fatty acids

Impaired oocyte quality is one of the main causes of low fertility in modern high-yielding dairy cows. One of the potential factors of the impaired oocyte quality is the effects of free fatty acids (FFA). In fact, high FFA supplementation to culture media exacerbated oocyte developmental competence in vitro. Meanwhile, artificially induced high blood FFA levels in heifers did not affect the lipid composition of oocytes in vivo; however, the oocyte lipid profile of postpartum cows has not yet been investigated. Therefore, the profile of lipids involved in energy metabolism, including FFA and triacylglycerols (TAG), and their relationship between plasma and oocytes were compared among cows at different lactation stages. Heifers were used as a control group that was not affected by lactation. Plasma and oocytes were collected from heifers (n = 4) and 14 Holstein cows categorized to the early lactation stage: 25–47 days in milk (DIM) (n = 6), peak lactation stage: 61–65 DIM (n = 4), and middle lactation stage: 160–202 DIM (n = 4). The FFA and TAG profiles of plasma and oocytes were examined by liquid chromatography mass spectrometry. Plasma FFA positively correlated with oocyte TAG (P < 0.05). Plasma FFA and oocyte TAG were significantly higher in cows in the early lactation stage than in heifers (P < 0.05), while the peak and middle lactation stage groups had intermediate levels. The proportion of oleic acid in plasma increased concurrently with elevations in total FFA, while the compositions of oocyte FFA and TAG fatty acyls were constant regardless of plasma FFA concentration or oocyte TAG content. The present results suggest that high postpartum plasma FFA concentrations affect the quantity of oocyte TAG. Taken together with the adverse effects of high FFA concentrations on oocyte developmental competence in vitro, oocyte quality in postpartum cows may be impaired due to high circulating FFA concentrations. These results provide a more detailed understanding of the effects of postpartum high circulating FFA concentrations on the low fertility of cows.

TRIB3 regulates FSHR expression in human granulosa cells under high levels of free fatty acids

BackgroundGranulosa cells (GCs) in cumulus oophorus highly express follicle stimulating hormone receptor (FSHR), which is the most important mediator of both estradiol synthesis and oocyte maturation. Obese women have elevated free fatty acids (FFAs) levels in their follicular fluids and decreased FSHR expression in GCs, which is related to an altered protein kinase B/glycogen synthase kinase 3β (Akt/GSK3β) signaling pathway. Such FFA increases accompany 3-fold rises in pseudokinase 3 (TRIB3) expression and reduce the Akt phosphorylation status in both the human liver and in insulinoma cell lines. Therefore, in a high FFA environment, we determined if TRIB3 mediates regulation of FSHR via the Akt/GSK3β signaling pathway in human GCs.MethodsGCs from women undergoing in vitro fertilization were collected and designated as high and low FFAs cohorts based on their follicular fluid FFA content. GCs with low FFA levels and a human granulosa-like tumor (KGN) cell line were exposed to palmitic acid (PA), which is a dominate FFA follicular fluid constituent. The effects were assessed of this substitution on the Akt/GSK3β signaling pathway activity as well as the expressions of TRIB3 and FSHR at both the gene and protein levels by qPCR, Western blot and immunofluorescence staining analyses. Meanwhile, the individual effects of TRIB3 knockdown in KGN cells and p-AKT inhibitors were compared to determine the mechanisms of FFA-induced FSHR downregulation.ResultsThe average FSH dose consuming per oocyte (FSH dose/oocyte) was elevated and Top embryo quality ratio was decreased in women with high levels of FFAs in their follicular fluid. In these women, the GC TRIB3 and ATF4 protein expression levels were upregulated which was accompanied by FSHR downregulation. Such upregulation was confirmed based on corresponding increases in their gene expression levels. On the other hand, the levels of p-Akt decreased while p-GSK3β increased in the GCs. Moreover, TRIB3 knockdown reversed declines in FSHR expression and estradiol (E2) production in KGN cells treated with PA, which also resulted in increased p-Akt levels and declines in the p-GSK3β level. In contrast, treatment of TRIB3-knockdown cells with an inhibitor of p-Akt (Ser473) resulted in rises in the levels of both p-GSK3β as well as FSHR expression whereas E2 synthesis fell.ConclusionsDuring exposure to a high FFA content, TRIB3 can reduce FSHR expression through stimulation of the Akt/GSK3β pathway in human GCs. This response may contribute to inducing oocyte maturation.

Investigation of Body Development in Growing Holstein Heifers With Special Emphasis on Body Fat Development Using Bioelectrical Impedance Analysis.

This study analyzed skeletal development, body condition, and total body fat development of growing heifers. A total of 144 female primiparous Holstein cattle from four commercial dairy farms with different degrees of stillbirth rates were examined during the rearing period. This included measurements in body condition, fat tissue, metabolic, and endocrine factors. Pelvic measurements and the sacrum height were analyzed to assess skeletal development. The body condition was classified via body condition scoring, bioelectrical impedance analysis (BIA), back fat thickness measurements, and the body mass. For the first time, BIA was used as an appropriate method to evaluate the fat tissue content of cattle throughout the rearing period. This analysis technique can be performed on heifers aged 8–15 months. Throughout that period, the fat content decreased while the skeletal development increased. In addition, high free fatty acid concentrations in serum of the animals with high frame development were found, supporting our hypothesis that stored energy of body fat deposits is used for skeletal growth. Furthermore, we were able to demonstrate complex endocrine relationships between fat metabolism and skeletal growth by using specific markers, such as leptin, insulin growth factor-1 (IGF-1), and estradiol (E2). Food analysis showed high crude protein (CP) levels in the total mixed ration above recommendation for daily protein intake of all farms. However, there was a positive correlation between CP and the body frame measurements in our study. In summary, we established a novel regression formula for BIA analysis (“BIA-Heine”) in heifers to evaluate the body composition throughout different ages and physiological stages in the development of heifers. This special formula allows the evaluation of fat tissue without a whole-body analysis and therefore provides an innovative technique for animal welfare support.

Influence of Free Fatty Acid Concentrations and Weight Loss on Adipose Tissue Direct Free Fatty Acid Storage Rates.

The factors that determine the recycling of free fatty acids (FFA) back into different adipose tissue depots via the direct storage pathway are not completely understood. To assess the interactions between adipocyte factors and plasma FFA concentrations that determine regional FFA storage rates. We measured direct adipose tissue FFA storage rates before and after weight loss under high FFA (intravenous somatostatin and epinephrine) and low (intravenous insulin and glucose) FFA concentrations. Mayo Clinic Clinical Research Unit. Sixteen premenopausal women, body mass index 30 to 37 kg/m2. Comprehensive lifestyle weight loss program. Direct FFA storage rates in upper and lower body subcutaneous fat. Over the entire range of FFA and under isolated conditions of elevated FFA concentrations, the storage rates of FFA into upper and lower body subcutaneous fat per unit lipid were associated with concentrations, not adipocyte fatty acid storage factors. Under low FFA conditions, direct FFA storage rates were related to adipocyte CD36 content, not tissue level content of fatty acid storage factors. Weight loss did not change these relationships. The regulation of direct FFA storage under low FFA concentration conditions appears to be at the level of the cell/adipocyte content of CD36, whereas under high FFA concentration conditions, direct FFA storage at the tissue level is predicted by plasma FFA concentrations, independent of adipocyte size or fatty acid storage factors. These observations offer novel insights into how adipose tissue regulates direct FFA storage in humans.

Effects of germinating temperature and time on metabolite profiles of sunflower (Helianthus annuus L.) seed.

Sprouts with higher levels of nutrients and lower content of antinutritional substances have been gained a growing interest in the influence on the human's health. The study of the influence of germination temperature and time on the metabolite profiles of sunflower seed was studied by a metabolomics approach based on gas chromatography–flame ionization detection (GC‐FID). Samples were extracted and fractionated covering a wide range of lipophilic and hydrophilic spectra. A total of 90 metabolites were identified by comparison with reference standards. Principal component analysis (PCA) revealed distinct dynamic changes in metabolites with the germinating time. Heatmap and agglomerative hierarchical clustering analysis revealed the differences and similarities among the samples. The germinating sunflower seeds clustered into three major groups. For instance, group I with a high content of sterols, monosaccharide, and amino acids, indicating the germination process, resulted in an increase in amino acids and monosaccharide. Group II had a high content of FAME and FFA. Relative targeted quantification of metabolites visually depicted by heatmap showed decreases in fatty acid methyl ester (FAME) and free fatty acid (FFA), and increases in amino acids, α‐tocopherol, sterols, and γ‐aminobutyric acid (GABA) during germination. Sunflower seeds germinated at 25°C were better for the accumulation of α‐tocopherol, stigmasterol, leucine, proline, methionine, glutamine, and GABA compared with those at 35°C. These results help to better understand how germination conditions change the nutritional quality of germinated sunflower seeds from a metabolite profile view, allowing for the rational screening and usage of germinated sunflower seeds in the food industry.

Mealworm (Tenebrio molitor) oil characterization and optimization of the free fatty acid pretreatment via acid-catalyzed esterification

The physical and chemical properties of mealworm (Tenebrio molitor) oil were studied. Mealworm powder has a high oil content of 37.54 ± 0.78% with a high free fatty acid (FFA) content of 10.84 ± 0.005%. The primary fatty acids of mealworm oil were oleic acid (30.37%), linoleic acid (25.07%) and palmitic acid (19.54%). The mealworm oil decomposed almost completely after 470 °C. An optimization study of acid-catalyzed esterification using response surface methodology (RSM) was conducted to reduce the high level of FFA content to a range below 1% to be suitably used for biodiesel production via alkali-catalyzed transesterification. The optimum parameters were 5.8% w/w sulfuric acid as catalyst, 24:1 methanol to oil ratio, 174 min reaction time at a temperature of 74 °C. The methyl esters conversion obtained using these optimum condition parameters was 92.74 ± 0.92% indicating FFA content was successfully lowered to less than 1%, which is favorable for alkali-catalyzed transesterification to take place and convert the triglycerides in the oil into biodiesel. The pretreated oil is then converted to biodiesel and the properties were found to meet the ASTM D6751 standards.

Development of Bi-Functional Heterogeneous Catalyst for Transesterification of Waste Cooking Oil to Biodiesel: Optimization Studies

Biodiesel production waste cooking oil is usually limited by its high free fatty acid and moisture content. The synergetic effect of both base and acid source from biomass was employed to proffer way out to this challenge. This study shows the coupled development of sulfonated carbonized corn cob (S-CCC) and calcined cow-bone (C-CB) catalysts for transesterification of waste cooking oil. The catalyst was prepared by physically mixing several mass percentages of S-CCC and C-CB (fluorapatite) in strategic proportions. The maximum biodiesel yield of 96.2 % was attained for catalyst mixture of 60 wt% and 40 wt%. The developed catalyst mixture was characterized by Fourier Transform Infrared Ray (FTIR), powder X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Brunauer–Emmett-Teller (BET). The surface area (472.3 m2/g), pore size (2.4330 nm) and volume (0.1380 cc/g) were obtained for the catalyst. The XRD shows that the crystallized structure of the bifunctional catalyst was formed majorly between 2 theta 10 and 65.Also the SEM shows a well dispersive pattern of the particles of the catalyst. The developed catalyst was employed for biodiesel optimization studies by varying factors such as time, temperature, catalyst loading and methanol: oil using optimal design under the response surface methodology. Maximum yield of 98.98 % was attained at time 6 h, temperature 65 °C, catalyst loading 6 %wt/ wt of oil and methanol to oil ratio of 11.75:1. It was observed that time and temperature had notable effect on the biodiesel yield.

Biodiesel production from non-edible high acid value phoenix seed oil using a cheap immobilized lipase

Fatty acid methyl ester (FAME) is one kind of renewable and biodegradable biodiesel energy. In this work, in order to decrease FAME production cost, a cheap immobilized lipase Lipozyme TLIM (Thermomyces lanuginosus lipase, 100$/kg) and waste phoenix seed (Firmiana platanifolia (L. f.) Marsili) oil with high free fatty acids (FFA) content (30.1 ± 0.4%) were used as catalyst and new feedstock, respectively. The effects of reaction variables were evaluated and optimized by response surface methodology. Results showed that Lipozyme TLIM can simultaneously catalyze the esterification and transesterification of high FFA phoenix seed oil to produce FAME. The conditions were optimized as follows: 11.8% water load added, 3.1:1 molar ratio of CH3OH to oil, and 7% lipase load at 33 °C for 6.47 h. High FAME yield (93.3 ± 1.6%) was achieved under the optimized conditions. Kinetic values (Vm and K’m) of FAME production were 2.66 × 10−2 mol/(L·min) and 7.4 mol/L, respectively, and the activation energy (Ea) was 42.62 kJ/mol. Therefore, a cheap immobilized lipase Lipozyme TLIM with a noted high level of tolerance of water could be useful in the industrial FAME production from phoenix seed oil with high FFA. After purified by molecular distillation, the contents of FAME, FFA, and water content of the final biodiesel product were 97.2%, 0.3%, and 0.04%, which were in accord with the quality standard of ASTM D6751 (>96.5%, <0.4%, and < 0.05%).

Biodiesel production from alternative raw materials using a heterogeneous low ordered biosilicified enzyme as biocatalyst

BackgroundCumulative reported evidence has indicated that renewable feedstocks are a promising alternative source to fossil platforms for the production of fuels and chemicals. In that regard, the development of new, highly active, selective, and easy to recover and reuse catalysts for biomass conversions is urgently needed. The combination of enzymatic and inorganic heterogeneous catalysis generates an unprecedented platform that combines the advantages of both, the catalytic efficiency and selectivity of enzymes with the ordered structure, high porosity, mechanical, thermal and chemical resistance of mesoporous materials to obtain enzymatic heterogeneous catalysts. Enzymatic mineralization with an organic silicon precursor (biosilicification) is a promising and emerging approach for the generation of solid hybrid biocatalysts with exceptional stability under severe use conditions. Herein, we assessed the putative advantages of the biosilicification technology for developing an improved efficient and stable biocatalyst for sustainable biofuel production.ResultsA series of solid enzymatic catalysts denominated LOBE (low ordered biosilicified enzyme) were synthesized from Pseudomonas fluorescens lipase and tetraethyl orthosilicate. The microscopic structure and physicochemical properties characterization revealed that the enzyme formed aggregates that were contained in the heart of silicon-covered micelles, providing active sites with the ability to process different raw materials (commercial sunflower and soybean oils, Jatropha excisa oil, waste frying oil, acid oil from soybean soapstock, and pork fat) to produce first- and second-generation biodiesel. Ester content ranged from 81 to 93% wt depending on the raw material used for biodiesel synthesis.ConclusionsA heterogeneous enzymatic biocatalyst, LOBE4, for efficient biodiesel production was successfully developed in a single-step synthesis reaction using biosilicification technology. LOBE4 showed to be highly efficient in converting refined, non-edible and residual oils (with high water and free fatty acid contents) and ethanol into biodiesel. Thus, LOBE4 emerges as a promising tool to produce second-generation biofuels, with significant implications for establishing a circular economy and reducing the carbon footprint.

Laminar shear stress upregulates the expression of PPARs in vascular endothelial cells under high free fatty acid‑induced stress

Shear stress has been reported to result in various metabolic effects in endothelial cells (ECs), which in turn contribute to the regulation of their vascular functions. Peroxisome proliferator-activated receptors (PPARs) have been reported to regulate lipid metabolism and have been implicated in metabolic disorders. The present study assessed the effects of laminar shear stress on the expression of PPARs in ECs in the presence of high concentrations of free fatty acids (FFAs). Human aortic ECs (HAECs) were treated with a high concentrations of palmitic acid (PA) and exposed to high shear stress (HSS) or low shear stress (LSS). Western blotting and ELISA were performed to quantify protein expression and assess prostacyclin production. The results revealed that long-term application of HSS to PA-treated HAECs induced PPAR-α, -δ and -γ protein expression. Additionally, LSS induced higher levels of PPAR-α protein expression in PA-treated HAECs compared with those after HSS. HAECs exposed to HSS also released prostacyclin (PGI2). However, HAECs treated with high concentrations of PA also produced high levels of PGI2 in the perfusion media in response to HSS compared with the static PA group. HSS also reduced the static PA-induced expression of intercellular adhesion molecule-1 and monocyte chemoattractant protein-1. The results demonstrated that HAECs increases the expression of all three peroxisome proliferator-activated receptor isoforms in response to shear metabolic stress at high FFA concentrations. The present study may provide preliminary insights into the potential roles of PPARs as an effective treatment method against metabolic disturbances that can result in EC dysfunction.

K2CO3 in NH4OH as an Effective Catalyst Mixture for the Transesterification of High Acid Value Mahua Oil

In present study, biodiesel was synthesized from high free fatty acid content Mahua oil using K2CO3 in NH4OH catalyst mixture through transesterification process. Addition of NH4OH to K2CO3, enhanced the basic strength of the catalyst (K2CO3) by generating in-situ KOH in ammonium carbonate medium. The presence of ammonium carbonate in the reaction medium controlled the generation of intermediate water during methoxide formation and thereby increased the biodiesel yield. The maximum yield of 98.5% with a fatty acid methyl ester (FAME) content of 98.95% was obtained at the optimized condition of catalyst mixture of 1g K2CO3 in 0.5 g of NH4OH, oil to methanol molar ratio 1:7 at 55 ºC in 75 min. Characterization of the obtained biodiesel has been carried out using GC-MS and 1H NMR techniques. The physico-chemical properties of the oil and the synthesized biodiesel were tested according to the ASTM D6751 standards and the values are within the range.