Journal of the American Oil Chemists Society最新文献

Silkworm pupae oil (SPO) with high amount of unsaturation due to rich in oleic acid and α-linolenic acids has been chosen for this investigation. Epoxidized silkworm pupae oil (ESPO) was produced by in situ generated peroxycitric with citric acid (CA) and hydrogen peroxide (H₂O₂). Literature covering the topic of epoxidation, including the catalytic aspect, is vast. No review articles have been written on the synthesis of epoxides from SPO without the catalyst to the best of our knowledge. Here, CA itself behaves as an oxygen carrier without any catalyst and H₂O₂ as an oxygen donor, which favors the epoxidation reaction. The epoxidation process was optimized by factors like temperature, time, and CA ratio. Fourier transform infrared (FTIR) analysis confirmed the presence of epoxy groups and the absence of (CC) bonds in ESPO. Optimal conditions for epoxidation were 70 °C, 0.75 mol/L CA, and 7 h, resulting in 92.1% double bond conversion (DBC) and 84.7% relative oxirane conversion (RC). The polymerized ESPO coated on mild steel (MS) exhibited enhanced corrosion resistance, with inhibition efficiency rising from 83.86% to 99.42% due to effective pore prevention and ion modification during curing.

Structured lipids (SLs) containing docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and DHA + EPA were synthesized via enzymatic acidolysis using virgin coconut oil (VCO) as the substrate in n-hexane. Commercially available enzymes Lipozyme TL IM (produced from Thermomyces lanuginosus, a 1,3-specific lipase), Lipozyme IM60 (produced from Rhizomucor miehei, a 1,3-specific lipase), and non-specific lipase from Candida rugosa (powder) were used as biocatalysts. The T. lanuginosus lipase was chosen to evaluate the effects of various parameters on the incorporation of PUFAs into VCO and to optimize the process. As the enzyme load increased from 1% to 4%, the incorporation of omega-3 PUFAs also increased; however, it decreased when the enzyme load was further increased to 6%. The incorporation of these fatty acids increased with reaction time from 12 to 36 h but decreased at 48 h. Similarly, the incorporation increased with temperature from 35 to 45 °C, but decreased at 55 and 65 °C. The highest incorporation rates of DHA (18.91%), EPA (30.38%), and DHA + EPA (34.64%) were achieved at a mole ratio of 1:3 (VCO to DHA or EPA) or 1:3:3 (VCO to DHA + EPA), with a 4% enzyme load, 36 h incubation time, and a temperature of 45 °C. A central composite design (CCD) with three levels and three factors—reaction temperature (35, 45, and 55 °C), enzyme amount (2%, 4%, and 6%), and reaction time (24, 36, and 48 h)—was used to model and optimize the reaction conditions via response surface methodology (RSM). Under optimal conditions of 3.3% T. lanuginosus enzyme, 42.22 °C, and 33.38 h, the incorporation rates were 32.92% for DHA, 44.48% for EPA, and 47.04% for DHA + EPA in VCO.

The soap content in biodiesel is an important challenge during the production and purification processing of biodiesel. Natural deep eutectic solvents (NADES) have recently attracted considerable interest as an environmentally suitable substitute for traditional solvents in the biodiesel industry. This work investigates the soap removal from the contaminated biodiesel using NADES. Eight choline chloride-based deep eutectic solvents (DESs) were screened using the conductor-like screening model for real solvents (COSMO-RS) to identify the most suitable solvent for soap removal and were validated experimentally. The effect of NADES molar ratio, NADES:biodiesel ratio, mixing speed and extraction time on the extraction efficiency were investigated. COSMO-RS screening revealed that the malonic acid-based NADES possess higher soap elimination, and this is compatible with the experimental screening. The higher extraction efficiency of 99.18% was achieved under the optimum conditions of 1:3 of NADES molar ratio, 1:1 DES:biodiesel, 150 rpm and 15 min of extraction time. The soap removal followed the first-order kinetic equation with a rate constant of 0.183 min⁻¹. This technique offers innovative and environmentally friendly routes for downstream processing of contaminated biodiesel.

Phospholipase C (PLC) enzymes play a pivotal role in the degumming process of edible oils, which is essential for producing high-quality refined oils. The enzymatic degumming process, compared with conventional chemical methods, offers significant advantages including improved oil yield, reduced environmental impact, and lower operational costs. However, the industrial application of PLC enzymes is often hindered by their limited stability under harsh processing conditions. This has driven extensive research efforts toward engineering thermostable PLC variants that can withstand the high temperatures and harsh environments typical of oil refining processes. In this review, we explore the latest advancements in the application, design and optimization of thermostable PLC enzymes. We discuss the fundamental economic and ecological interest behind the goal of obtaining thermostable enzymes, and two approaches to the problem, namely the search for enzymes in thermophilic organisms and the design of new sequences with improved stability and activity parameters.

Thermal decomposition of hydroperoxides during frying generates several secondary oxidation products, with carbonyl compounds predominating. p-Anisidine value (p-AV) is the most prominent official method for quantifying these carbonyl compounds, utilizing the reaction between carbonyls, principally 2-alkenals and 2,4-dienals, and p-anisidine (para-methoxy aniline) reagent. It is well known, however, that despite the success of the p-AV test, the data is generally skewed toward the unsaturated carbonyl compounds and the reagent is highly toxic and presumably, carcinogenic, limiting its acceptability in some food processing settings. A method proposed in the current study utilizes the reaction between carbonyl compounds, specifically aldehydes, and purpald reagent (4-Amino-3-hydrazino-5-mercapto-1,2,4-triazole). Unlike the p-AV, the purpald test is very specific to aldehydes with negligible interference from other functional groups (e.g., ketones, carboxylic acids, esters). Interestingly, the reaction between aldehydes and purpald reagent is skewed toward saturated aldehydes by nearly the same factor that the p-AV is skewed toward unsaturated aldehydes, providing a complimentary information to the p-AV on the nature of secondary aldehydes formed during thermo-oxidative degradation of lipid hydroperoxides. Further, a second method utilizing p-anisidine hydrochloride reagent was optimized for the determination of carbonyl secondary oxidation compounds. A strong correlation was found between each of the proposed alternatives and the p-AV method, providing the opportunity for indirect determination for p-AV in food processing settings where the p-anisidine reagent is considered unacceptable regarding environmental health and safety. Challenges and limitations of the proposed chemical alternative methods are also presented.

The growing environmental consciousness and research into green lubricant technology in various industries has drawn a lot of attention to vegetable oils. The major negative aspect of vegetable oil is its poor oxidation stability. Recent research in ionic liquids (ILs) showed its potential as a base fluid and additive for lubricant applications. These are organic salts that dissolve at temperatures below 100°C. Among the potential characteristics of ILs are their non-volatility, high oxidation stability, non-flammability, and high conductivity to heat and electricity. The present study synthesized a protic ionic liquid named dioctyl ammonium oleate (DAO). The optimum DAO percentage in rice bran oil (RBO) was then optimized based on the tribological properties. The electrical conductivity and basic lubricant properties, such as physicochemical, oxidation stability, corrosion stability, thermal properties, and extreme pressure capability of the optimized RBO-DAO blend were evaluated and compared with RBO. The developed RBO-DAO blend shows the potential to be used as a base fluid for electrical conductive lubricants due to its significantly enhanced electrical conductivity, better oxidation stability, and superior tribological properties. The optimum DAO weight percentage in RBO is 2 wt%. The results show the potential of electrical conductive lubricant developed to enhance the performance of electrical equipment, reduce static electricity in industrial machinery, and prevent lubricant degradation in the presence of electric current. The components of electric vehicles, such as bearings, pads, seals, and gear, also require electrical conductive lubricants to avoid premature failure and electromagnetic interference problems. The developed lubricant can be considered a potential alternative in various industries such as automotive, renewable systems, medical devices, robotics, high-speed machining, and so forth.

Plant germplasm is the most basic genetic resource for plant cultivar improvement and development. Mining germplasm collections can identify accessions that are advantageous for breeding programs. To identify sesame accessions with desirable seed nutritional quality traits, the entire USDA sesame collection (1231 accessions) was screened for seed oil content, fatty acid composition, and 100-seed weight. We identified significant variability in 100-seed weight (mean: 0.32 g, range: 0.1–0.5 g) and oil content (mean: 54.9%, range 28.3%–65.5%) among the accessions. Sesame seeds mainly contained four major fatty acids: 44.8% linoleic acid (18:2), 39.5% oleic acid (18:1), 9.0% palmitic acid (16:0), 5.2% stearic acid (18:0) and six minor fatty acids: 0.1% palmitoleic acid (16:1), 0.4% linolenic acid (18:3), 0.6% arachidic acid (20:0), 0.2% gadoleic (20:1), 0.1% behenic acid (22:0), and 0.1% lignoceric acid (24:0). For each trait, two accessions were classified as having high 100-seed weight (PI 238992: 0.54 g and PI 250626: 050 g), high oil content (PI 238992: 65.5% and PI 250626: 64.2%), or high oleic acid levels (PI 263470: 54.4% and PI 263454: 50.3%). For most accessions, levels of oleic and linoleic acid were related to country origins where the germplasm accessions were collected. The information on these seed nutritional quality traits is useful, but breeding efforts or genetic methods are needed for developing new sesame cultivars or enhanced germplasm with these traits. Among 1231 accessions, nine accessions were further evaluated for additional seed nutritional quality traits and accession PI 263470 was successfully used as starting genetic material for mutagenesis to enhance levels of oleic acid.

The application of edible coatings allows the shelf life of food products to be extended, since they provide physical resistance, reduce the moisture exchange of the product, and also reduce oxygen permeability, avoiding chemical changes such as nutrient oxidation. The objective of this study was to develop an edible coating made from sunflower protein flour and apply it to roasted sunflower seeds as a preservation procedure for this food product. Roasted sunflower seeds were prepared with and without sunflower coating and stored for 60 days at room temperature. Samples were extracted every 15 days to determine the peroxide values (PV), conjugated dienes (CD) and volatile compounds. The uncoated seeds showed the highest PV (83.7 mEqO₂/kg at Day 15 and 149.2 mEqO₂/kg at Day 60), while the coated seeds presented lower values (39.2 and 69.3 mEqO₂/kg at 15 and 60 days, respectively). Regarding the DC values, this parameter also showed the same behavior as PV. Thirteen volatile compounds were identified in analyzed samples (by GC–MS), where hexanal, 2-octenal and nonanal showed significant variations. The uncoated sunflower seeds showed a greater release of volatile compounds. According to the correlation analysis, hexanal presented the highest correlation value between CD and PV in coated (0.76 and 0.79, respectively) and uncoated seeds (0.70 and 0.91, respectively). The obtained results suggest that, although the oxidative reactions occur in roasted sunflower seeds, the application of the coating delays this deterioration process, slows down the oxidation of lipids and contributes to prolonging the useful life of this product.

The primary goal of the study was to compare the efficacy of two approaches, photochemical and thermal, in producing polyols from renewable soybean oil through thiol-ene reactions. The thiol-ene reaction was initiated with UV light in the presence of 2-hydroxy-2-methylpropiophenone as a photo-initiator or via a thermal pathway utilizing radical initiator 2,2′-Azobis(2-methylpropionitrile). The resulting polyols were analyzed using standard analytical techniques including Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopies. It was observed that the polyols obtained through the photochemical route exhibited better outcome compared with those synthesized using the thermal treatment. Additionally, we employed computational chemistry technique using density functional theory (DFT) calculation to get insights into various product yields. The DFT results revealed that the hydrogen bond network likely contributed to the improved stability, hence obtained higher product yield of the polyol MSBO-TMPAE compared with that of MSBO-GAE. Our study also focuses on applying the synthesized polyols in polyurethane rigid foams and casts. The polyurethanes prepared from these polyols have comparable thermal and mechanical properties to that of the commercially available polyurethanes.

The recognized health benefits associated with marine omega-3 polyunsaturated fatty acids (PUFAs) have increased their demands and prices, prompting the search for new marine materials as lipid sources. Considering stricter health, safety, and environmental regulations, it is crucial to advocate the transition from chlorinated solvents like chloroform and dichloromethane to sustainable alternatives. This study aimed to assess the lipid extraction efficiency of the ethyl acetate (EtOAc) method compared to the Folch method across four marine resources. The tested species were Atlantic salmon (Salmo salar Linnaeus, 1758) and three low-trophic species: the zooplankton Calanus finmarchicus (Gunnerus, 1770), the microalgae Porosira glacialis (Grunow) Jörgensen, 1905, and the macroalgae Saccharina latissima (Linnaeus). Our results indicated that the EtOAc method is as efficient as the Folch method in extracting lipids from Atlantic salmon fillets and freeze-dried C. finmarchicus (p > 0.05). However, the relative lipid yields from frozen and freeze-dried P. glacialis and S. latissima were 49.5% and 27.3%, respectively, when substituting the Folch method with the EtOAc method. Therefore, we recommend the adoption of EtOAc as a sustainable alternative for materials high in neutral lipids to avoid the underestimation of polar and complex lipids. However, the proportion of PUFAs in the extracted lipids was determined not only by the choice of solvent but also by the biological composition of the materials. We encourage future efforts to choose a suitable lipid extraction method considering the characteristics of the raw materials and their composing lipids, in addition to the trade-offs between extraction efficiency and sustainability.