Esterification Of Stearic Acid Research Articles

A membrane targeted multifunctional cationic nanoparticle conjugated fusogenic nanoemulsion (CFusoN): induced membrane depolarization and lipid solubilization to accelerate the killing of Staphylococcus aureus.

Bacterial infections caused by Staphylococcus aureus are one of the growing concerns for human health care management globally. Antibiotic-associated adverse effects and the emergence of bacterial resistant strains necessitate the development of an alternative yet effective approach. Nanoemulsion-based therapy has emerged as a potential therapeutic strategy to combat bacterial infestation. Herein, we designed a cationic metal nanoparticle-conjugated fusogenic nanoemulsion (CFusoN) as a lipid solubilizing nanovesicle for the effective treatment of S. aureus infection with a killing efficiency of 99.999%. The cationic nanoparticle-conjugated nanoemulsion (viz. NECNP) (24.4 ± 2.9 mV) electrostatically bound with the negatively charged bacterial cell membrane (-10.2 ± 3.7 mV) causing alteration of the bacterial surface charge. The fluorometric and flow cytometry studies confirmed the bacterial membrane depolarization and altered cell membrane permeability leading to cell death. The atomic force microscopic studies further demonstrated the damage of the cellular ultrastructure, while the transmission electron microscopic image and membrane lipid solubilization analysis depicted the solubilization of the bacterial membrane lipid bilayer along with the leakage of the intracellular contents. The cell membrane fatty acid analysis revealed that the methyl esters of palmitic acid, stearic acid and octadecadienoic acid isomers were solubilized after the treatment of S. aureus with CFusoN. The bactericidal killing efficiency of CFusoN is proposed to occur through the synergistic efficacy of the targeted attachment of CNP to the bacterial cells along with the lipid solubilization property of NE. Interestingly, NECNP didn't elicit any in vitro hemolytic activity or cytotoxicity against red blood cells (RBCs) and L929 fibroblast cells, respectively, at its bactericidal concentration. Furthermore, a porcine skin wound infection model exhibited the enhanced wound cleansing potency of CFusoN in comparison to the commercially available wound cleansers. The obtained antibacterial activity, biocompatibility and skin wound disinfection efficacy of the NECNP demonstrated the formulation of a cell targeted CFusoN as a promising translatable strategy to combat bacterial infection.

Chemically vs Enzymatically Synthesized Polyglycerol-Based Esters: A Comparison between Their Surfactancy.

Polyglycerol fatty acid esters (PGFAEs) are gaining interest in several industrial sectors due to their excellent surfactant properties and their wide range of hydrophilic-lipophilic balance (HLB) values. Moreover, they can be prepared from renewable resources, i.e., fatty acids and glycerol. In this study, polyglycerol-2 stearic acid esters (PG2SAEs) were synthesized by the enzymatic esterification of polyglycerol-2 (PG2) and stearic acid (SA) using the immobilized lipase Novozym 435 as a biocatalyst in a solvent-free system. Reaction conditions, i.e., temperature (80 °C), reactant ratio (1:1.8), and enzyme loading (2.7% w/w), were finely optimized; furthermore, biocatalyst recycling was studied by assessing the residual activity of the lipase after each reaction cycle, up to 20 times. The composition of the enzymatically synthesized products (E) was roughly evaluated by chromatographic methods and mass spectrometry and compared with that of the esters obtained by acid-catalyzed esterification (C). Then, the surfactant properties of the prepared polyglycerol-based surfactants were investigated by interfacial tension studies. Specifically, the emulsifying capacity and stability and the rheological behavior of O/W emulsions prepared in the presence of E were deeply investigated in comparison with those of the chemically synthesized and commercially available product C.

Esterification of stearic acid using novel protonated and crosslinked amidoximated polyacrylonitrile ion exchange fibres

This study will demonstrate the conversion of stearic acid to methyl stearate (biodiesel) using for the first time crosslinked amidoximated polyacrylonitrile ion-exchanged mesh protonated by sulphuric acid. Quantitative analysis of conversion was by GC-FID, 1H NMR and ATR-FT-IR with GC-FID the most reliable. A molar ratio of methanol to stearic acid of 35.5: 1 gave 94 % conversion to the ester at 90 °C. At 65 °C and a greater ratio of 87.1:1 conversion was 94.1 % comparable to the 98 % yield obtained with 1wt% H2SO4. Re-use at 65 °C gently dropped to 57 % on the 13th cycle. Regeneration by washing with dichloromethane and re-acidification achieved 84 % conversion but quickly deactivated due to blocking of sites by methyl stearate as shown by ATR-FTIR. This protonated amidoxime PAN catalyst (distinct from sulfonated fibres) exhibited higher stability than other heterogeneous protonated catalysts (ion-exchange resins, zeolites, clays) used lower temperatures and shorter reaction times. Advantages of using a mesh in place of powders are its ease of removal/replacement for continuous flow reactors promoting quick changes in process parameters. This study is promising as providing a sustainable protonated catalyst for use in converting Fats, Oils and Greases (FOG’s) in waste oils and wastewater to biodiesel.

Effect of drug load and lipid–wax blends on drug release and stability from spray-congealed microparticles

This study was designed to evaluate paraffin wax as a potential controlled release matrix for spray congealing and its impact on drug release and stability of the microparticles. Paraffin wax can form a hydrophobic barrier to moisture and reduce drug degradation besides retarding drug release in the gastrointestinal tract. More hydrophilic lipid-based additives can be incorporated to modulate the drug release through the paraffin wax barrier. This study reports the findings of lipid–wax formulations at preserving the stability of moisture-sensitive drugs in spray-congealed microparticles. Aspirin-loaded microparticles formulated with different drug loads, lipid additives, and lipid:wax ratios were produced by spray congealing. Stearic acid (SA), cetyl alcohol (CA), and cetyl ester (CE) were the lipid additives studied. The microparticles were evaluated for yield, encapsulation efficiency, particle size, drug stability, and release. CE exhibited the greatest effect on increasing drug release, followed by CA and SA. Dissolution profiles showed the best fit to Weibull kinetic model. The degree of drug degradation was low, with CA imparting the least protective effect, followed by SA and CE. Paraffin wax is useful for preserving the stability of moisture-sensitive aspirin and retarding its release from spray-congealed microparticles. The addition of lipid additives modulated drug release without compromising drug stability.

Activity of a Sulfonated Carbon-Based Catalyst Derived from Organosolv Lignin toward Esterification of Stearic Acid under Near-Critical Alcohol Conditions.

In this study, an environmentally benign carbon-based catalyst derived from extracted bagasse lignin (EL) was successfully synthesized by solvothermal carbonization and sulfonation with methane sulfonic acid (MSA). Interestingly, the results indicated that the use of MSA as a sulfonation agent made a catalyst with higher thermal stability than conventional sulfuric acid. Thus, in comparison to the catalyst prepared by using sulfuric acid, the catalyst prepared by using MSA (EL-MSA) exhibited higher catalytic activity in the esterification of stearic acid under near-critical methanol conditions. Under optimum conditions (260 °C for 5 min, a 9:1 methanol-to-stearic-acid molar ratio, 5 wt % catalyst loading, and 10% v/v toluene), the esterification over the EL-MSA catalyst promoted a 91.1% methyl stearate yield. Moreover, the results also revealed that the high thermal stability of the EL-MSA catalyst not only affects its great catalytic activity, but it also prevents damage to the porous structure and decomposition of acidic surface oxygen-containing functional groups. It contributes to the excellent reusability of the catalyst. After the fifth run, a high yield of 82.8% was obtained. The effect of alcohol type on the catalyst performance was also studied. It was found that the EL-MSA catalyst also presented good performance toward esterification with ethanol and propanol, from which ethyl stearate and propyl stearate with a more than 80% ester yield can be achieved.

Novel Method for Producing Oleophilic Polyurethane Foam to Remove Oil from Open Water

In this study, a novel recyclable, hydrophobicity foam with excellent oil/water separation based on polyurethane (PU) and polypropylene glycol (PPG) grafted stearic acid (PGGA) has been developed. PGGA was simply synthesized by the esterification of stearic acid and PPG, while the PU/PGGA foam was fabricated by the reaction of PPG and methyl diphenyl diisocynate (MDI) with the addition of PGGA. The PU/PGGA foam exhibits improved oil adsorption capacity, water rejection as well as oil/water selectivity with the increase of PGGA weight loadings. The presence of PGGA at high loading (≥ 5 wt%) reduces the pore size and porosity of PU/PGGA foam due to the high viscosity of PGGA preventing the foam formation reaction. As a result, the oil adsorption capacity of PU/PGGA foam is slightly neglected, nevertheless, the oil/water selectivity is significantly enhanced compared to the original PU foam. The result in this work suggests a simple and cost-effective method with potential in oil removal at large scale application.Graphical AbstractIn this study, novel hydrophobicity agent (PGGA) is developed for enhancing the oil/water separation of polyurethane (PU) foam. At lower weight loading of PGGA (≤ 3 wt%), the PU/PGGA foam exhibits improvement in oil adsorption capacity, water rejection and oil/water separation. Above 5 wt% loading of PGGA, the oil adsorption of PU/PGGA foam is decreased, however, the oil/water selectivity were drastically improved. With this result, the PU/PGGA foam is highly potential for oil removal at large scale application.

Synthesis of sulfonated carbon-based catalysts from organosolv lignin and methanesulfonic acid: Its activity toward esterification of stearic acid

This work aims to offer a new acid type, methanesulfonic acid, to produce environmentally benign sulfonated carbon-based catalysts for esterification. The sulfonated catalysts were synthesized using two types of lignin sources, commercial lignin (CL) and lignin extracted from sugarcane bagasse (EL) through solvothermal carbonization and followed by sulfonation step. Overall, lignin sources and types of sulfonic acids were the factors affecting the catalyst performance. The results indicated that the high oxygenated functional groups on surface of chars prepared from EL gave the materials with better catalytic performance than prepared from CL. Moreover, the catalysts functionalized with methanesulfonic acid presented the higher catalytic activity than with sulfuric acid due to their higher surface area and better thermal stability. The highest methyl stearate yield (89.2%) from esterification of stearic acid with methanol were achieved at 240 °C with the reaction time of 10 min using the molar ratio of stearic acid to methanol of 1:9 and catalyst loading of 5 wt% in case of using EL char as a carbon source and methanesulfonic acid as a sulfonating agent. The catalyst could also be reused up to seven cycles with a yield higher than 80%.

Preparation of Highly Stable Oil-in-Water Emulsions with High Ethanol Content Using Polyglycerol Monofatty Acid Esters as Emulsifiers

Oil-in-water (O/W) emulsions containing ethanol have been used in food, cosmetics, paints, and other applications. However, O/W emulsions with long-term stability are difficult to produce at high ethanol concentrations because the adsorption of the emulsifier at the O/W interface is restricted by ethanol. In this study, to resolve this issue, we prepared ethanol-containing O/W emulsions with high dispersion stability using a series of polyglycerol monofatty acid esters (PGFEs) with different fatty acid chain lengths, which are bio-safe nonionic surfactants, as emulsifiers. First, aqueous PGFE solutions containing 0-50 wt% ethanol were prepared and then O/W emulsions were formed using limonene as the oil phase. When decaglycerol stearic acid ester (DGMS, C18) was used as the emulsifier, an O/W emulsion with fine droplets (~30 nm in size) was successfully obtained at an ethanol concentration of 35 wt%. This emulsion remained stable for more than four weeks, during which no phase separation occurred, indicating its high dispersion stability. Furthermore, aqueous DGMS solutions containing 30-40 wt% ethanol were viscous, and a lamellar liquid crystal phase was observed to be dispersed in these solutions. The formation of this lamellar liquid crystal phase at the O/W interface led to an interfacial film with superior viscoelastic properties. The results suggested that the stability of the emulsions was determined by the balance between the decrease in interfacial tension caused by the addition of ethanol and the density (rigidity) of the DGMS film formed at the O/W interface. Finally, to further improve the dispersion stability of the ethanol-containing O/W-type emulsions, O/W emulsions were prepared using a mixture of two PGFEs with different degrees of glycerol polymerization, that is, systems having different hydrophilic-lipophilic balance values.

Application and toxicity studies of arabinoxylan and \u03b2-d-glucan stearic acid ester composite coatings in extending postharvest storage of peach

Peaches are good source of nutrients and known for their taste and aroma. The highly perishable nature of the peaches tends to decay rapidly during transportation and storage is a serious constraint for efficient transportation and storage. Therefore, the effect of arabinoxylan (AX) and β-D-glucan stearic acid ester (SABG) composite coating material was examined for the postharvest storage quality of peach under storage at 22 ± 2 °C with 85% relative humidity (RH). Both, AX-SABG and shellac (1–2%) coatings significantly reduced the change in the quality attributes like weight loss (1.2–1.4 fold), respiration rate (1.1–1.2 fold), ripening index (1.3–1.5 fold) and firmness (1.3–1.5 fold) during 6 days storage as compared to the uncoated peaches. In addition, AX-SABG (1–2%) coating was more effective in retaining aroma volatiles and reducing disease incidence compared to shellac. Further, acute and chronic toxicological studies have shown no tissue related toxicity and mortality in mice. Our results suggest that AX-SABG as an edible coating has the potential to preserve the fruit quality during 6 days storage at 22 ± 2 °C and extend the postharvest shelf life of peach during storage.

Chemical profiling and anti-breast cancer potential of hexane fraction of Sphaeranthus indicus flowers

Purpose: The current study aimed to determine the phytochemicals and anti-breast cancer potential of Sphaeranthus indicus.Methods: S. indicus flowers were extracted with methanol followed by fractionation using n-hexane. For the chemical composition of n-hexane fraction, qualitative phytochemical and GC-MS analysis were performed. The anti-proliferative activity was measured by MTT assay, whereas, cytotoxic and proapoptotic effects in MCF-7 (breast cancer) cells were determined using propidium iodide, 4′,6-diamidino- 2-phenylindole, dichlorofluorescin diacetate, and JC-1 staining through fluorescent microscopy.Results: The phytochemical analysis indicated presence of phytosterols, oils and resins in the nhexane fraction. GC-MS analysis showed that n-hexane fraction comprises of 11 compounds including methyl esters of caprylic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid and behanic acid. The tested fraction showed remarkable cytotoxic activity against breast cancer (MCF-7) cells while it was found less toxic towards non-cancerous (BHK-21) cells. Furthermore, morphological assessment through fluorescent microscopy revealed cytotoxic and apoptotic effects by improved cell membrane permeability, increased reactive oxygen species level, compromised mitochondrial activity and condensation of chromatin network.Conclusion: The n-hexane fraction of S. indicus contains phytosterols, oils and fatty acid methyl esters and produced apoptotic effect against breast cancer cells.

Docosahexaenoic Acid Esters of Hydroxy Fatty Acid Is a Novel Activator of NRF2.

Fatty acid esters of hydroxy fatty acids (FAHFAs) are a new class of endogenous lipids with interesting physiological functions in mammals. Despite their structural diversity and links with nuclear factor erythroid 2-related factor 2 (NRF2) biosynthesis, FAHFAs are less explored as NRF2 activators. Herein, we examined for the first time the synthetic docosahexaenoic acid esters of 12-hydroxy stearic acid (12-DHAHSA) or oleic acid (12-DHAHOA) against NRF2 activation in cultured human hepatoma-derived cells (C3A). The effect of DHA-derived FAHFAs on lipid metabolism was explored by the nontargeted lipidomic analysis using liquid chromatography-mass spectrometry. Furthermore, their action on lipid droplet (LD) oxidation was investigated by the fluorescence imaging technique. The DHA-derived FAHFAs showed less cytotoxicity compared to their native fatty acids and activated the NRF2 in a dose-dependent pattern. Treatment of 12-DHAHOA with C3A cells upregulated the cellular triacylglycerol levels by 17-fold compared to the untreated group. Fluorescence imaging analysis also revealed the suppression of the degree of LDs oxidation upon treatment with 12-DHAHSA. Overall, these results suggest that DHA-derived FAHFAs as novel and potent activators of NRF2 with plausible antioxidant function.

Distinct roles of adipose triglyceride lipase and hormone‐sensitive lipase in the catabolism of triacylglycerol estolides

Branched esters of fatty acids and hydroxy fatty acids (FAHFAs) belong to a wide range group of lipids, some of which have anti-inflammatory and anti-diabetic properties. FAHFAs themselves belong to oligomeric FA esters, known as estolides. Depending on structure, they are divided in subfamilies (e.g. palmitic acid esters of hydroxy stearic acid, PAHSAs) including several regioisomers with different position of the branching position (e.g. 9-PAHSA). In human and mice tissue, glycerol-bound FAHFAs in triacylglycerols (TAGs), named TAG estolides, serve as metabolite reservoir of FAHFAs mobilized by lipases upon demand. Here, we studied the role of two major metabolic lipases, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), in TAG estolide and FAHFA degradation. We synthesized a panel of twenty TAG estolide isomers with different FAHFAs groups varying in branching position, chain length, saturation grade, and position on the glycerol backbone. An in silico mass spectra library was developed of all predicted catabolic intermediates. Homogenates of HEK293T cells overexpressing ATGL, or HSL were used for the determination of TAG estolide hydrolase activity of HSL and ATGL in the presence or absence of comparative gene identification-58 (CGI-58). White adipose tissue from ad libitum fed and fasted wild-type and global HSL knock-out mice was collected and TAG estolides were quantified. We found that ATGL alone or coactivated by CGI-58 efficiently liberated FAHFAs from TAG estolides with a preference for more compact substrates where the estolide branching point is located near the glycerol ester bond. ATGL also participated in transesterification and remodeling reactions leading to the formation of TAG estolides with alternative acyl compositions. HSL represented a much more potent estolide bond hydrolase for both TAG estolides and free FAHFAs. FAHFA and TAG estolide accumulation in white adipose tissue of mice lacking HSL argued for a functional role of HSL in estolide catabolism in vivo. Our data show that ATGL and HSL participate in the metabolism of estolides and TAG estolides in distinct manners and are likely to affect the lipokine function of FAHFAs.

Synthesis of poly(vinyl chloride)-co-poly(acrylic acid) by precipitation polymerization and its usage as CaCO3 modifier in rigid PVC composites

Incorporating carboxyl group into the poly(vinyl chloride) (PVC) resin can endow PVC with reactivity in some applications. In this work, poly(vinyl chloride)-co-poly(acrylic acid) random copolymer (PVCA) with low average number molecular weight (M n, ∼10 k) is synthesized by precipitation polymerization. By tuning acrylic acid dropping rate, the PVCA copolymer with much more uniform copolymer composition is obtained in comparison to all monomer-in process. Subsequently, the PVCA is utilized as a novel polymer modifier for the surface treatment of CaCO3 particles and its effect on the mechanical properties of obtained rigid PVC composites are evaluated systematically. As a result, the PVAC modified CaCO3 particles exhibit uniform dispersibility and excellent compatibility in PVC matrix. Additionally, the thermal stability is improved significantly owing to the calcium ions on the surface of CaCO3 particles, which scavenge the hydrogen chloride and retard the autocatalytic dehydrochlorination process. Impressively, it also has an enhancement both in tensile strength (ca. 46.4 MPa, and 119.8% elongation at break) and in impact strength (2.7 kJ m−2) in comparison to those modified by commercialized agents such as stearic acid and titanate ester. This work provides valuable insights for the preparation of vinyl chloride copolymers and opens a new application.

Synthesis and evaluation of novel acrylic and ester-based polyols for transparent polyurethane coating applications

In the current study, the primary focus was concentrated on the synthesis and evaluation of two types of polyol systems namely acrylic and ester-based polyol (AP and EP) which can be further used as a component for the development of polyurethane coating. Both the polyols were synthesized with variable monomer compositions. The acrylic-based polyol was obtained by free-radical polymerization of monomers like Hydroxyethyl methacrylic 2-Hydroxyethyl acrylic, Isobornyl methacrylic, Butyl acrylic, Methyl methacrylic, Methacrylic acid, and Styrene in presence of di-tert-butyl peroxide (initiator). Besides, the ester-based polyols were synthesized by the esterification of stearic acid with the help of trimethylolpropane in the presence of oxalic acid or hexahydro-4-methylphthalic anhydride. The hydroxyl value of each polyol system was calculated in accordance with the ASTM D4274-99 standard and then the configuration and chemical structure were confirmed by FTIR and 1H NMR spectroscopy. The molecular weight distribution was confirmed by performing GPC whereas decomposition behavior was studied by TGA analysis. Higher hydroxyl value results in better performance of the polyols and AP- 1 and EP- 1 were found to be the most favorable systems to be used forward for the synthesis of polyurethane. Furthermore, PU coating was formulated and a preliminary study was conducted at various AP and EP concentrations, and their optical, mechanical and morphological properties were evaluated in order to validate the uses of polyols in PU coatings. This optimization was found to be true and in agreement with other characterization results.

Synthesis of Sulfonated Carbon-Based Catalysts from Organosolv Lignin and Methanesulfonic Acid: Its Activity Toward Esterification of Stearic Acid

Synthesis of Sulfonated Carbon-Based Catalysts from Organosolv Lignin and Methanesulfonic Acid: Its Activity Toward Esterification of Stearic Acid

Distinct roles of adipose triglyceride lipase and hormone-sensitive lipase in the catabolism of triacylglycerol estolides

Branched esters of palmitic acid and hydroxy stearic acid are antiinflammatory and antidiabetic lipokines that belong to a family of fatty acid (FA) esters of hydroxy fatty acids (HFAs) called FAHFAs. FAHFAs themselves belong to oligomeric FA esters, known as estolides. Glycerol-bound FAHFAs in triacylglycerols (TAGs), named TAG estolides, serve as metabolite reservoir of FAHFAs mobilized by lipases upon demand. Here, we characterized the involvement of two major metabolic lipases, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), in TAG estolide and FAHFA degradation. We synthesized a library of 20 TAG estolide isomers with FAHFAs varying in branching position, chain length, saturation grade, and position on the glycerol backbone and developed an in silico mass spectra library of all predicted catabolic intermediates. We found that ATGL alone or coactivated by comparative gene identification-58 efficiently liberated FAHFAs from TAG estolides with a preference for more compact substrates where the estolide branching point is located near the glycerol ester bond. ATGL was further involved in transesterification and remodeling reactions leading to the formation of TAG estolides with alternative acyl compositions. HSL represented a much more potent estolide bond hydrolase for both TAG estolides and free FAHFAs. FAHFA and TAG estolide accumulation in white adipose tissue of mice lacking HSL argued for a functional role of HSL in estolide catabolism in vivo. Our data show that ATGL and HSL participate in the metabolism of estolides and TAG estolides in distinct manners and are likely to affect the lipokine function of FAHFAs.

Influence of fatty acid composition on process optimization and characteristics assessment of biodiesel produced from waste animal fat

ABSTRACT This present study focus on the process optimization and characteristic assessment of waste animal fat (WAF) biodiesel based on the influence of fatty acids characterized in it. WAFs were rendered from leather fleshing (subcutaneous fat, 85.64%) and slaughterhouse (intramuscular fat, 8.46%) wastes using dry rendering technique, wherein the maximum renderable fat content was found to be 75.77% and 5.89%, respectively. Ethyl esters of oleic acid, palmitic acid, and stearic acid were characterized as dominant fatty acid esters (FAEs) in WAF biodiesel. Optimized transesterification on waste fats using ethanol and synthesized D-valine amido ethyl methyl imidazolium chloride ([D-Vaemim]Cl) as novel ionic liquid (IL) catalyst yielded 97.36% of biodiesel. High molar ratio (WAF to ethanol:6) and reaction temperature (75°C) were accounted by the long-chain fatty acids in triglyceride molecules and their higher degree of saturation, respectively, meanwhile, [D-Vaemim]Cl exhibited high conversion yield beyond 10% and was effective up to 10 cycles. Similarly, biodiesel properties were evaluated as per ASTM D6751 standards, were found to be in acceptable range, and were deeply influenced by carbon chain length and degree of unsaturation in FAE molecules. Also, the presence of long-chain saturated FAEs along with fuel bound oxygen induced superior combustion characteristics and controlled emission concentrations. However, slight reduction in engine performance was due to high viscosity and reduced calorific value of biodiesel which was reflected from its FAE molecules.

Biodiesel production via stearic acid esterification over mesoporous ZrO2/SiO2 catalysts synthesized by surfactant-assisted sol-gel auto-combustion route

Abstract Biodiesel production from the esterification of stearic acid with ethanol catalyzed by the mesoporous ZrO2/SiO2 catalysts which successfully synthesized by surfactant-assisted sol-gel auto-combustion method. These catalysts were characterized by various physico-chemical techniques such as XRD, BET surface area measurement, HR-TEM and NH3-TPD. The mesoporous catalyst prepared with cationic surfactant (ZrSiOC) showed a maximum BET surface area and pore volume. Interestingly, the ZrSiOC catalyst exhibited the largest acidity value among all catalysts. The results showed that the mesoporous ZrO2/SiO2 catalysts prepared with cationic (ZrSiOC) and non-ionic (ZrSiOT) surfactants demonstrated higher stearic acid conversion than those with anionic (ZrSiOS) or without surfactant (ZrSiO). Significantly, the ZrSiOC and ZrSiOT catalysts exhibited the highest conversion of 69.2% and 63.1% at 120 °C after 3 h, respectively. Additionally, it was observed that the conversion increased extremely with increasing the reaction temperature giving a maximum conversion of 76.9% at 125 °C by using the most active catalyst (ZrSiOC). Interestingly, the ZrSiOC catalyst displays suitable recycling as it kept performance of 72.5% after five recycle runs without significant lack in performance. Moreover, the kinetic study confirmed that esterification follows pseudo first-order equation.

Improved postharvest quality of apple (Rich Red) by composite coating based on arabinoxylan and β-glucan stearic acid ester

Apples (Rich Red) were coated with wheat straw arabinoxylan (AX) and β-glucan stearic acid ester (SABG) composite coating material in the concentration range of 1–2%. The postharvest storage life of coated apples was studied at 22 °C (±2) with 65% and 85% relative humidity for 45 days. Application of both AX-SABG (1–2%) and shellac (1–2%) coatings material significantly reduced the weight loss, respiration process, color degradation, process of fruit softening and ripening index as compared to the uncoated apples up to 30 days storage. However, the AX-SABG coatings were found more effective in preventing the aroma loss, reducing microbial spoilage and maintaining sensorial attributes as compared to shellac and uncoated apples during storage.

Biodiesel Production by Acid Methanolysis of Slaughterhouse Sludge Cake.

Simple SummaryExcessive sludge in the wastewater treatment basins has to be removed periodically to ensure good water quality of the effluent. This study aims to evaluate the feasibility of biodiesel production by acid methanolysis of slaughterhouse sludge cake. Experimental and analytical results showed that acid methanolysis of sludge cake was one of the feasible and practical options to recycle sludge waste and produce renewable energy.Biosludge is a normal form of accumulating microbial populations inside the sewage or wastewater treatment facilities. Excessive sludge in the wastewater treatment basins has to be removed periodically to ensure good water quality of the effluent. This study aims to evaluate the feasibility of biodiesel production by transesterification of slaughterhouse sludge cake. The sludge cake was collected from a selected commercial slaughterhouse and transesterified with methanol, n-hexane, and acids (e.g., sulfuric acid or hydrochloric acid) at 55 °C. Three acid concentrations (2%, 4%, and 8%, v/v) in methanol under four reaction time periods (4, 8, 16, and 24 h) were applied. Results showed that the highest accumulated fatty acid methyl ester (FAME) yields of 2.51 ± 0.08% and 2.27 ± 0.09% were achieved when 8% (v/v) of H2SO4 or HCl were added in a 4 h reaction time, respectively. Methyl esters of palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), and oleic acid (C18:1n9c) were the major components of biodiesel from acid methanolysis of slaughterhouse sludge cake. Experimental and analytical results of acid methanolysis of slaughterhouse sludge cake showed that acid methanolysis of sludge cake was one of the feasible and practical options to recycle sludge waste and produce renewable energy.