Unsaturated Vegetable Oils Research Articles

Oil unsaturation degree dictates emulsion stability through tuning interfacial behaviour of proteins

The unsaturated vegetable oil is commonly incorporated as protein-stabilized emulsion into fat-substituted emulsified meat products (FSEMP), whose quality is closely related with the emulsion stability. Here, we systematically investigated the effects of oil unsaturation degree (UD) on the interfacial properties (structural changes, adsorption dynamics, interfacial rheology, adsorption layer thickness) of proteins and thus the emulsion stability. The oleic acid and linolenic acid were mixed with dodecane as model oils. Three types of proteins were selected as model emulsifiers (fibrous myofibrillar protein, MP; globular whey protein, WP; random-coiled sodium caseinate, SC). The proteins diffused slower to the higher UD interface, resulting in a lower interfacial pressure. This led to a larger droplet size of the higher UD oil emulsion upon emulsification. However, the proteins penetrated and rearranged faster at the higher UD interface ascribed to a more extensive structural unfolding, enabling the formation of stiffer and thicker adsorption layers. This contributed to a stronger short-term stability of MP- and WP-stabilized higher UD oil emulsion; while for the random-coiled SC, the higher UD oil emulsion was less short-term stable, which was primarily determined by the initial (larger) droplet size but not the interfacial layer properties. The stiffer layer at the higher UD interface was on the other hand less stretchable, which tended to yield when subjected to higher strain. This probably accounted for the weaker long-term stability of the higher UD oil emulsion, regardless of protein types. These results highlighted that the oil UD should be elaborately considered for the rational formulation of FSEMP.

An electrochemical sensor based on electrochemically activated carbon cloth and poly (o-aminothiophenol) cross-linked nanogold imprinted layer for the determination of tert-butylhydroquinone

In this study, an electrochemical sensor based on MoS2 with enhanced electrochemical signals from electrochemically activated carbon cloth (EACC) electrodes and cross-linked o-aminothiophenol functionalized AuNPs (o-ATP@AuNPs) was developed for the detection of the unsaturated vegetable oil antioxidant tert-butylhydroquinone (TBHQ). In this approach, carbon cloth is activated through the implementation of electrochemical methods, thereby effectively increasing its specific surface area. The resulting EACC, serving as an electrode substrate, enables the growth of additional nanomaterials and enhances conductivity. The incorporation of MoS2 effectively augments the sensitivity of the electrochemical sensor. Subsequently, MIP/MoS2/EMCC is formed via electropolymerization, utilizing TBHQ as the template molecule and o-ATP@AuNPs as the functional monomer. The SS bond of o-ATP ensures a strong and stable connection between MoS2 and o-ATP@AuNPs, thereby facilitating the immobilization of MIP. In addition, the high conductivity possessed by o-ATP@AuNPs could effectively improve the sensitivity of the electrochemical sensor. Under the optimal conditions, MIP/MoS2/EMCC could determine TBHQ in the range of 1 × 10−3 μM to 120 μM by differential pulse voltammetry (DPV) with a detection line of 0.72 nM. The proposed MIP/MoS2/EMCC is expected to be applied in the future for the selective and sensitive detection of TBHQ in vegetable oils.

1,4-Diol Hq (TBHQ) vs 1,4-dithiol (TBDT); simulation of safe antioxidant with a lower carcinogenic activity.

tert-Butylhydroquinone (TBHQ) is an antioxidant and preservative used in unsaturated vegetable oils and processed foods. However, when consumed in higher doses daily, it may pose a threat to public health by potentially increasing the risk of cancer, as it has an affinity with both the aryl hydrocarbon receptor (AhR) and the estrogen receptor alpha (ERα). This study aimed to examine the impact of substituting the 1,4-diol of TBHQ with 1,4-dithiol, referred to as TBDT, on the carcinogenic and antioxidant systems using computational methods. The binding affinity of TBHQ and TBDT to the two carcinogenic receptors, AhR and ERα, as well as to the antioxidant receptor Keap1 alone and in connection with Nrf2 (Nrf2-Keap1) was investigated through docking analysis. The results indicated a decrease in TBDT's binding strength to ERα and AhR when assessed using Molegro Virtual Docker (P-value: 0.0001 and 0.00001, respectively), AutoDock Vina (P-value: 0.0001 and 0.0001), and the online server Fast DRH (P-value: 0.0001 and 0.0001). However, TBDT's binding affinity to Keap1 was predicted to be significantly stronger than TBHQ's by both MVD and AutoDock Vina (P-value: 0.0001 and 0.04), while its binding to Nrf2-Keap1 assessed to be stronger only by MVD (P-value: 0.0001). These findings suggest that TBDT not only exhibits higher antioxidant activity as a better ligand for the antioxidant system but also shows lower affinity with the AhR and ERα receptors. Therefore, TBDT can be considered a safer compound than TBHQ.

Itaconic Anhydride as a Green Compatibilizer in Composites Prepared by the Reinforcement of a Tung Oil-Based Thermosetting Resin with Miscanthus, Pine Wood, or Algae Biomass

Unsaturated vegetable oils with conjugated carbon–carbon double bonds, such as tung oil, can undergo free-radical polymerization, originating alternatives to petroleum-based materials. The introduction of fillers to vegetable oil-based polymer matrices results in composites with improved mechanical properties. In this work, thermosets were synthesized by the free-radical polymerization of a mixture of tung oil, divinylbenzene, and n-butyl methacrylate, and reinforced with bio-based fillers, namely Miscanthus, Pinus taeda (also known as southern pine), and algae (Microspora and Oedogonium) biomass. The effect of filler particle size on the composites’ properties was evaluated. Additionally, to develop a better interaction between the hydrophobic resin and the hydrophilic reinforcements, and improve the mechanical properties of the composites prepared, itaconic anhydride, a bio-based molecule derived from itaconic acid, was added to the resin. Thermogravimetric analysis (TGA) showed that the presence of itaconic anhydride improved the overall thermal stability of the composites. The storage modulus of the composites at room temperature, assessed by dynamic mechanical analysis (DMA), was increased by approximately 32% and 68%, for Miscanthus and southern pine composites, respectively, when itaconic acid was added to the resin. It was also observed that the glass transition temperatures were not significantly affected by the presence of itaconic acid. Scanning electron microscope (SEM) images indicated better matrix-reinforcement adhesion in the presence of itaconic anhydride.

Electron beam-cured linseed oil - Diacrylate blends as a green alternative to overprint varnishes: Monitoring curing efficiency and surface coating properties

Electron beam (EB)-cured unsaturated vegetable oil and diacrylate was formulated as an alternative and green overprint varnish (OPV) for coatings in a finishing process. Linseed oil (LO) was applied with tripropylene glycol diacrylate (TPGDA) in different ratios to obtain EB-curable LO-based OPV (eLOPV). The eLOPV were irradiated by EB for curing using various absorbed doses of 10–100 kGy. Change of the functional groups, chemical structure and transition temperature of EB-cured eLOPV were characterized by FTIR, 13C-NMR and DSC. The curing efficacy was assessed by measuring conversion, gel fraction, swelling degree and by characterizing surface properties using solvent rub-test and cross-cut tape test methods. The EB-cured eLOPV exhibited great surface adhesion on substrates. The surface morphologies of the EB-cured eLOPV on papers and plywood sheets were observed by SEM. The results indicate that the eLOPV (LO-TPGDA blend 40: 60 w/w) was completely cured using EB at 30 kGy. Th optical properties were observed via yellowness and whiteness indexes according to ASTM E 313. Color difference and gloss value were measured using colorimeter and gloss meter, respectively. The eLOPV provide good surface qualities, i.e, good surface adhesion, low yellowness, homogeneous cured surface, high gloss value, and hydrophobic surface. Aiming at well-optimized formula and effective EB-curing process, the synthetic chemical can be reduced at least 50% w/w by using vegetable oil without photo-initiator. The utilization of LO and EB curing technology is a promising strategy for bio-/green-coatings approach.

Lightning impulse breakdown performance of saturated vs unsaturated vegetable oil and their mixtures with mineral oil

This paper presents the results of the experimental studies on lightning impulse breakdown tests of two categories of vegetable oil – saturated versus unsaturated. The saturated vegetable oils comprise refined, bleached, and deodorized coconut oil and virgin coconut oil (i.e., RBDCO and VCO), while the unsaturated vegetable oil is the most commonly used soybean oil called ‘MIDEL eN1215′. The differences in the impulse breakdown performance of the two categories of vegetable oil were analyzed from the perspective of molecular ionization and ionization potential. The effect of the residual mineral oil on impulse breakdown performance was also studied and analyzed. A point-sphere electrode system was used in this study. It is observed that at a 12.5 mm gap, the lightning impulse breakdown voltage (LIBDV) of both RBDCO and VCO were nearly similar to natural ester oil (NEO) subjected to positive excitation, but with negative excitation, the latter appears to be inferior. At twice the electrode gap, LIBDV can easily differentiate between unsaturated and saturated vegetable oils, whatever be the polarity of excitation. With mineral oil, up to 20%, LIBDVs of vegetable oil tend to increase. This is mainly important with positive excitation, especially in NEO, where up to a 25% increase was observed as against pure oil.

Plant-Based Dietary Patterns for Human and Planetary Health.

The coronavirus pandemic has acted as a reset on global economies, providing us with the opportunity to build back greener and ensure global warming does not surpass 1.5 °C. It is time for developed nations to commit to red meat reduction targets and shift to plant-based dietary patterns. Transitioning to plant-based diets (PBDs) has the potential to reduce diet-related land use by 76%, diet-related greenhouse gas emissions by 49%, eutrophication by 49%, and green and blue water use by 21% and 14%, respectively, whilst garnering substantial health co-benefits. An extensive body of data from prospective cohort studies and controlled trials supports the implementation of PBDs for obesity and chronic disease prevention. The consumption of diets high in fruits, vegetables, legumes, whole grains, nuts, fish, and unsaturated vegetable oils, and low in animal products, refined grains, and added sugars are associated with a lower risk of all-cause mortality. Meat appreciation, health concerns, convenience, and expense are prominent barriers to PBDs. Strategic policy action is required to overcome these barriers and promote the implementation of healthy and sustainable PBDs.

Evaluation of Dietary Patterns and All-Cause Mortality

The 2020 Dietary Guidelines Advisory Committee conducted a systematic review of existing research on diet and health to inform the current Dietary Guidelines for Americans. The committee answered this public health question: what is the association between dietary patterns consumed and all-cause mortality (ACM)? To ascertain the association between dietary patterns consumed and ACM. Guided by an analytical framework and predefined inclusion and exclusion criteria developed by the committee, the US Department of Agriculture's Nutrition Evidence Systematic Review (NESR) team searched PubMed, the Cochrane Central Register of Controlled Trials, and Embase and dual-screened the results to identify articles that were published between January 1, 2000, and October 4, 2019. These studies evaluated dietary patterns and ACM in participants aged 2 years and older. The NESR team extracted data from and assessed risk of bias in included studies. Committee members synthesized the evidence, developed conclusion statements, and graded the strength of the evidence supporting the conclusion statements. A total of 1 randomized clinical trial and 152 observational studies were included in the review. Studies enrolled adults and older adults (aged 17-84 years at baseline) from 28 countries with high or very high Human Development Index; 53 studies originated from the US. Most studies were well designed, used rigorous methods, and had low or moderate risks of bias. Precision, directness, and generalizability were demonstrated across the body of evidence. Results across studies were highly consistent. Evidence suggested that dietary patterns in adults and older adults that involved higher consumption of vegetables, fruits, legumes, nuts, whole grains, unsaturated vegetable oils, fish, and lean meat or poultry (when meat was included) were associated with a decreased risk of ACM. These healthy patterns were also relatively low in red and processed meat, high-fat dairy, and refined carbohydrates or sweets. Some of these dietary patterns also included intake of alcoholic beverages in moderation. Results based on additional analyses with confounding factors generally confirmed the robustness of main findings. In this systematic review, consuming a nutrient-dense dietary pattern was associated with reduced risk of death from all causes.

Dietary Patterns and All-Cause Mortality: A NESR Systematic Review

Abstract Objectives To inform the 2020–2025 Dietary Guidelines for Americans, the U.S. Departments of Agriculture (USDA) and Health and Human Services (HHS) identified important public health questions to be examined by the 2020 Dietary Guidelines Advisory Committee. The Committee conducted a systematic review with support from USDA's Nutrition Evidence Systematic Review (NESR) team to answer the following question: What is the relationship between dietary patterns consumed and all-cause mortality? Methods The Committee developed protocols that described how they would use NESR's systematic review methodology to examine the evidence related to dietary patterns and all-cause mortality. NESR librarians conducted a literature search. NESR analysts dual-screened the results using pre-defined inclusion and exclusion criteria to identify articles published between 2000 and 2019 that evaluated dietary patterns and all-cause mortality. NESR analysts extracted data and assessed risk of bias of included studies. The Committee synthesized the evidence, developed conclusion statements, and graded the strength of the evidence underlying the conclusion statements. Results This review included one hundred and fifty-three studies, which were well-designed and conducted using rigorous methods, with low or moderate risks of bias. Precision, directness, and generalizability were demonstrated across the body of evidence. Results across studies were highly consistent in the foods and beverages included in the dietary patterns associated with reduced ACM risk. Robustness of results were confirmed by analyses with confounding factors. Conclusions Strong evidence demonstrates that dietary patterns in adults and older adults characterized by vegetables, fruits, legumes, nuts, whole grains, unsaturated vegetable oils, and fish, lean meat or poultry when meat was included, are associated with decreased risk of all-cause mortality. These patterns were also relatively low in red and processed meat, high-fat dairy, and refined carbohydrates or sweets. Some of these dietary patterns also included alcoholic beverages in moderation. (Grade: Strong) Funding Sources USDA, Food and Nutrition Service, Center for Nutrition Policy and Promotion, Alexandria, VA.

Nutrition for Pregnant and Lactating Women: The Latest Recommendations From the Dietary Guidelines for Americans 2020-2025 and Practice Implications.

The influence of maternal nutrition and dietary intake is intergenerational. In recognizing that diet-related chronic conditions, such as obesity and diabetes, especially during conception and pregnancy, are associated with childhood obesity and diabetes risk, the latest Dietary Guidelines for Americans 2020-2025 includes an emphasis on lifespan nutrition. Research supports the need to achieve a healthy weight preconception, as women with a high body mass index before pregnancy are at risk for excessive gestational weight gain, gestational diabetes, hypertension, caesarian section delivery, and excessive postpartum weight retention, which sets the stage for subsequent risk in future pregnancies. The Dietary Guidelines committee emphasized that key components to healthy dietary patterns include higher consumption of vegetables, fruits, nuts, legumes, whole grains, lean meat and seafood, dairy, and unsaturated vegetable oils and lower consumption of processed meat, foods high in saturated fat and cholesterol, and foods and drinks with added sugar. The guidelines offer health care providers, individuals, and other stakeholders with a framework of strategies that can help individuals achieve optimal health. This framework can be utilized to develop individualized approaches for implementing culturally relevant interventions.

Comparison of epoxidation methods for biobased oils: dioxirane intermediates generated from Oxone versus peracid derived from hydrogen peroxide

AbstractA study was carried out to compare the epoxidation of unsaturated vegetable oils using dioxirane intermediates generated in situ using Oxone to that by the peracid/hydrogen peroxide method. Epoxidized oils are typically synthesized using hydrogen peroxide, as well as acetic or formic acid. This synthesis requires heating and catalysts and generates acidic waste. Recently, advances have been made in the process of using Oxone (potassium peroxymonosulfate) and ketones to generate in situ dioxiranes to epoxidize alkenes. The dioxirane method allows for room temperature reactions and eliminates the use of peroxides and acids. Epoxidation of soybean oil, hempseed oil and sucrose soyate using in situ generated dioxiranes was carried out and parameters such as molar ratios and addition rates were studied. The data show that optimum reaction conditions are reached when molar ratios of Oxone and unsaturation are 1.6:1 and the Oxone addition rate is 1 mL min–1. As a comparison, epoxidations using the acetic acid/hydrogen peroxide method were carried out and cured materials were prepared from the epoxidized compounds. Negligible differences were identified in the materials prepared from both synthetic pathways. An environmental sustainability assessment using green chemistry principles was also conducted for both methods to evaluate their safety and efficiency with respect to multiple criteria including minimizing waste generation and energy consumption. The analysis shows that, although the peracid method is atom economic and generates less waste, the dioxirane method offers better occupational safety and requires less energy, demonstrating the tradeoffs involved with either pathway if one is to be selected. © 2021 Society of Chemical Industry

Heavy metal sorption using thiolated oils of Elaeis guineensis and Glycine max

Sulphur-modification of matter confers improved heavy metal affinity and could be exploited in the treatment of heavy metal contaminated water. This paper is aimed at comparing the liquid-liquid Ag+ sorption capacities of normal and thiolated: palm oil (PO), palm kernel oil (PKO) and soybean oil (SBO), respectively. The vegetable oils were modified with 1-heptanethiol, and the thioether-functionalized (TF) oils were utilized for the removal of Ag+ present as a contaminant in water, while the unmodified oils acted as controls. The liquid-liquid equilibrium contact time was determined to be 6 hours. The result achieved after equilibration revealed the effectiveness of TF oils in the removal of Ag+ from a 600 ppm AgNO3 simulated water. While TF-SBO reduced the cation concentration to a level less than the detection limit, TF-PKO only showed appreciable sorption capacity (below 30%) relative to the normal oils. The order of Ag+ sorption capacity (TF-SBO > TF-PO > TF-PKO) was ascribed to various levels of unsaturation of fatty acid chains encountered in the lipids. A higher number of sorption-active TF sites is achievable with a greater degree of fatty acid unsaturation. On that note, highly unsaturated vegetable oils (such as that of Glycine max) were recommended.

An Overview of Natural Extracts with Antioxidant Activity for the Improvement of the Oxidative Stability and Shelf Life of Edible Oils

Many plant materials, such as fruits and vegetables as well as herbs and spices, represent valuable sources of antioxidants. In recent years, wastes from agriculture and food industrial processes have been shown to be interesting sources for bioactive compound recovery, strongly contributing to the circular economy. Nowadays, because of their possible adverse effects on human health, there is a tendency to replace synthetic antioxidants with natural compounds. This review attempts to critically summarize the current evidence on plant bioactives, extracted from food or waste, added to unsaturated vegetable oils, in order to obtain high added-value products and to ameliorate their oxidative stability and shelf life. The goal of this review is to demonstrate the current status of the research on edible oils added with natural plant bioactives, highlighting new approaches in the field of health-promoting foods.

Antioxidant efficacy and in silico toxicity prediction of free and spray-dried extracts of green Arabica and Robusta coffee fruits and their application in edible oil

Extracts of green coffee fruits (GCFEs), either of the Arabica or Robusta variety, obtained by percolation with a 68% (w/w) aqueous ethanol solution using a 0.9:10 (w/w) solid-to-solvent ratio, were tested in this study as antioxidant additives to delay sunflower oil oxidation. In addition, safety of the major secondary metabolites of the extracts was investigated by in silico modeling. For this purpose, GCFEs were spray dried either as such or microencapsulated with a 1:1 (w/w) maltodextrin and gum Arabic mixture as wall material. The encapsulation efficiencies of Arabica and Robusta GCFEs were as high as 96.9 ± 0.04 and 97.36 ± 0.03% and the chlorogenic acid retentions 59.61 ± 1.3 and 73.72 ± 2.49%, respectively. The HPLC-DAD analysis revealed higher contents of total chlorogenic acids and caffeine but a lower content of trigonelline in the Robusta GCFE compared with the Arabica one. The ACD/I-Lab, AdmetSAR, and pKCSM computational tools allowed excluding, for GCFEs major compounds, any toxicological potential in terms of Ames toxicity, carcinogenicity, hERG inhibition, hepatotoxicity, reproductive toxicity and skin sensitization. Foodstuff application of GCFE powders demonstrated that microencapsulated GCFEs were more effective in delaying sunflower oil oxidation than free GCFEs and butylated hydroxytoluene as a synthetic antioxidant. These results suggest the use of microencapsulated GCFE as a source of natural antioxidants to stabilize food products, especially unsaturated vegetable oils.

The effect of heating on the formation of 4-hydroxy-2-hexenal and 4-hydroxy-2-nonenal in unsaturated vegetable oils: Evaluation of oxidation indicators

The formation of 4-hydroxy-2-hexenal (HHE) and 4-hydroxy-2-nonenal (HNE) in vegetable oils and model oil systems were quantitatively assessed by RP-HPLC. Regardless of heating temperature, HHE was only detected in rapeseed and linseed oil, while HNE was detected in all tested oils. Intrinsic tocopherols suppressed HHE/HNE formation, but with similar inhibition rates (10.49–16.04%). Linear correlations were observed between HHE/HNE contents and corresponding n-3/6 fatty acid content in oils (R2 = 0.989/0.971). Model oil system revealed that HHE/HNE formation was closely related to methyl linolenate (MLN) and methyl linoleate (ML) contents. Low levels of ML (<0.5%) and MLN (<1.0%) did not lead to HHE/HNE formation. Therefore, HHE/HNE was classified as the characteristic aldehydes of n-3 and n-6 type oils, respectively. Heat map evaluation and regression analysis indicated HHE could predict the n-3 type oils oxidation, while HNE was a good indicator to estimate the oxidative deterioration of n-6 and n-9 type oils.

Synthesis and Properties of Thermosets from Tung Oil and Furfuryl Methacrylate.

This work focuses on the development of cross-linked polymer from a highly unsaturated vegetable oil, tung oil (TO) and a bio-based acrylate, furfuryl methacrylate (FMA). The presence of a high degree of unsaturated carbon-carbon bonding in TO makes it a suitable precursor for polymer synthesis. Using this advantage of TO, in this work, we have synthesised a cross-linked polymer from TO and FMA through free radical polymerisation followed by Diels–Alder (DA) reaction. Successful incorporation of both of the raw materials and the two chemical reactions was shown using Fourier-transform infrared (FTIR) and Raman spectroscopy. The development of cross-linked structure was analysed through thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA).

Bio-Based Composites with Enhanced Matrix-Reinforcement Interactions from the Polymerization of α-Eleostearic Acid

Vegetable oil-based composites have been proposed as interesting bio-based materials in the recent past. The carbon–carbon double bonds in unsaturated vegetable oils are ideal reactive sites for free radical polymerization. Without the presence of a reinforcement, typical vegetable oil-based polymers cannot achieve competitive thermo-mechanical properties. Compatibilizers have been utilized to enhance the adhesion between resin and reinforcement. This work discusses the antagonist implications of polarity and crosslink density of an unprecedented polar α-eleostearic acid-based resin reinforced with α-cellulose, eliminating the need of a compatibilizer. It is shown that the polar regions of α-eleostearic acid can interact directly with the polar reinforcement. The successful isolation of α-eleostearic acid from tung oil was verified via GC-MS, 1H NMR, Raman, and FT-IR spectroscopies. The optimal cure schedule for the resin was determined by DSC and DEA. The composites’ thermo-mechanical properties were assessed by TGA, DSC, and DMA.

Comparison of different oleogels in processed cheese products formulation

SummaryThis study investigates the potential usage of unsaturated vegetable oil oleogel to replace solid milk fat in processed cheese products (PCPs). Soybean oil was gelled using rice bran wax (RBW) or sunflower wax (SW) at two different concentrations and used to produce PCPs with final concentrations of 0.5% or 1% wax. An ungelled oil PCP and a commercial milk fat processed cheese (CC) were produced for comparison. Upon compositional analysis, moisture and fat content were similar between oleogel PCPs (OPCP) and the CC sample; however, lower saturated fat content was observed in the OPCPs. Samples’ microscopy analysis revealed that the incorporation of oleogels reduced oil agglomeration observed in the ungelled PCPs, which confirms the presence of a higher oil holding capacity in the OPCPs. Rheological and thermomechanical analysis demonstrated comparable hardness, storage modulus and meltability values between the OPCPs and the control samples. This study provides insight into the potential applications for oleogels in the replacement milk fat in processed cheese products with desirable properties.

Lipase catalyzed epoxidation of fatty acid methyl esters derived from unsaturated vegetable oils in absence of carboxylic acid

Nowadays the industrial chemistry reactions rely on green technologies. Enzymes as lipases are increasing its use in diverse chemical processes. Epoxidized fatty acid methyl esters obtained from transesterification of vegetable oils have recently found applications as polymer plasticizer, agrochemical, cosmetics, pharmaceuticals and food additives. In this research article, grapeseed, avocado and olive oils naturally containing high percents of mono and poly unsaturations were used as starting materials for the production of unsaturated fatty acid methyl esters. The effect of lauric acid as an active oxygen carrier was studied on epoxidation reactions where unsaturated fatty acid methyl esters were converted to epoxy fatty acid methyl esters using immobilized Candida antarctica Lipase type B as catalyst and hydrogen peroxide as oxygen donor at mild temperature and pressure conditions. After this study it was confirmed by 1H NMR, 13C NMR and GC–MS that the addition of lauric acid to the enzymatic reaction is unnecessary to transform the alkenes in to epoxides. It was found that quantitative conversions were possible in despite of a carboxylic acid absence.

Trans fatty acids and conjugated linoleic acid in food: origin and biological properties

Trans fatty acids (TFA) are minor lipid components present in different foods, including ruminant derived products, which have received great attention due to their relationship with cardiovascular disease risk. The origin of TFA in food is mainly related to the industrial hydrogenation processes of unsaturated vegetable oils, but they can also occur naturally in the digestive tract of ruminants by enzymatic biohydrogenation reactions. Both mechanisms generate similar TFA compounds. However, TFA consumption may exert different biological effects depending on the isomeric distribution, which is strongly influenced by the dietary source (i.e., industrial or natural). Industrial hydrogenated vegetable fats are rich in elaidic (trans-9 18:1) and trans-10 18:1 fatty acids, among others. In contrast, vaccenic acid (trans-11 18:1) is the major TFA isomer detected in milk and other ruminant derived products. Vaccenic acid is the physiological precursor of conjugated linoleic acid, a bioactive lipid with beneficial effects on human health. This article provides updated information on the biological effects and potential bioactive properties of TFA considering both, their chemical structure and provenance.