Tert-butylhydroquinone Research Articles

Computational study of synthetic and natural polymer additives — Antioxidant potential of BHA, TBHQ, BHT, and curcumin

The antioxidant potential of commonly used synthetic and natural antioxidant additives, including butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), tert‑butylhydroquinone (TBHQ), and natural additive, curcumin have been studied and compared by calculating the bond dissociation enthalpy (BDE), ionization potential (IP), proton dissociation enthalpy (PDE), proton affinity (PA), and electron transfer enthalpy (ETE) values for each potential hydrogen donor site. The results indicate that, in each additive an OH group has the highest antioxidant potential (lowest BDE value). The studied molecules can be ranked based on their antioxidant potential as follows: BHT > BHA ≈ TBHQ > curcumin A > curcumin D. By comparing with commonly used polymers, in each studied species, there is at least one X-H bond which has a lower BDE value than in the corresponding polymeric material. Thus, all studied additives are potentially applicable to protect polymeric materials. BHT is the best radical scavenger additive in case of the hydrogen atom transfer (HAT), and the sequential proton loss electron transfer (SPLET) mechanisms to donate a H atom, but in single electron transfer proton transfer (SETPT) curcumin could also be suitable.

Evaluation of Oxidative Stability of Cupcake Oil: Comparison of Antioxidant Properties of Dracocephalum kotschyi Essential Oil versus TBHQ

AbstractGiven the phytochemical properties of Dracocephalum kotschyi, this research considers the effects of adding its essential oil to cupcakes and investigation of the its oil oxidative stability. At first D. kotschyi’s essential oil (DKEO) is identified and measured by GC/MS. The results show that the most important components of DKEO are α‐pinene (25.50%), geranial (14.01%), limonene (12.39%), and neral (11.07%). Chemical analyses on pH, acidity, peroxide value, p‐Anisidine value, and total oxidation value (TOTOX) show that increasing the concentration of DKEO reduces the oxidation rate and increases the oxidative stability of the cupcake's oil during storage. Sensory evaluation shows that DKEO used concentration does not have favorable effects on some organoleptic properties of cupcakes. Despite the positive effects of DKEO on maintaining the oxidative stability of cupcake's oil during baking and storage, lower concentrations of it are recommended, along with combinatory usages of this essential oil with other commonly used essential oils in the confectionery industry (such as cinnamon, ginger, and cardamom essential oils), whereby consumers can be gradually accustomed to new flavors.Practical applications: The present study introduces the Dracocephalum kotschyi as a rich source of antioxidants. In the present study, valuable data are presented to compare the application of natural antioxidants of D. kotschyi versus a synthetic antioxidant like tert‐butylhydroquinone (TBHQ) in a popular product. In addition, D. kotschyi is introduced as a natural antioxidant potential to the oil industry and oil‐dependent food industries, which can not only reduce the nutritional risks of synthetic antioxidants, but also increase the marketability of oil‐rich food products.

RETRACTED: Exploration over combined impacts of modified piston bowl geometry and tert-butyl hydroquinone additive-included biodiesel/diesel blend on diesel engine behaviors

Nowadays, the use of biodiesel for diesel engines has been attracting researchers aiming to improve engine characteristics although the engine performance could be decreased while utilizing biodiesel. In this aspect, optimizing the piston bowl geometry is one of the useful approaches to enhance the efficiency of the biodiesel-powered diesel engine. In this study, the standard piston of an existing diesel engine was modified into two different combustion bowls, namely Symmetrical Stepped Curved-V (SSCV) and Symmetrical Spline-V (SSV), to evaluate the CI engine performance powered with mixtures of sesame-originated biodiesel, diesel fuel, and tert-butyl hydroquinone (TBHQ) additive through two-stage experiment. In the first phase, experiments were carried out on two modified piston bowls powered by diesel and S20 (20% sesame biodiesel + 80% diesel fuel). Resultantly, SSV piston revealed superior engine characteristics to SSCV piston and standard piston due to enhanced air–fuel mixing and more complete combustion of SSV piston-based engine. Indeed, SSV piston operation exhibited an 8.68% of increased brake thermal efficiency (BTE), 6.54% of curtailed brake-specific fuel consumption (BSFC), 4.76% of lowered carbon monoxide (CO), 4.84% of decreased unburnt hydrocarbon (HC), and 2.22% of lowered smoke opacity but with increased nitrogen oxide (NOx) by 14.14% in comparison to diesel. In the 2nd phase, to control the NOx emission effectively, a TBHQ additive was added to the S20 sample at different proportions (500 mg and 1000 mg) to analyze the test engine behaviors with modified piston shapes. As a result, S20 + 500 mg TBHQ at 100% load improved BTE by 5.79% and reduced BSFC by 4.36% in the case of SSV piston. Moreover, it curtailed emissions of CO, HC, NOx, and smoke opacity by 13.33%, 15.49%, 12.09%, and 9.44%, respectively, when equated with diesel. Overall, S20 + 500 mg TBHQ could be thought of as a possible alternative fuel on SSV piston as it resulted in superior performance and emission characteristics in the existing standard engine. The current study's findings could pave the way for the development of diesel engines with modified piston geometry that is more efficiently compatible with biodiesel blends and additives.

Two Novel Lipophilic Antioxidants Derivatized from Curcumin.

Tert-butyl curcumin (TBC), demethylated tert-butylated curcumin (1E,6E-1,7-bis(3-tert-butyl-4,5-dihydroxyphenyl)hepta-1,6-diene-3,5-dione, DMTC), demethylated curcumin (DMC), and Cur were synthesized from the starting compound, 2-methoxy-4-methylphenol. TBC and DMTC are two novel lipophilic compounds, and Cur and DMC are polar and hydrophilic. The antioxidant activities of Cur, TBC, DMC, and DMTC were evaluated by using the methods of 2,2-diphenyl-1-(2,4,6-trinitro-phenyl)-hydrazinyl (DPPH), deep-frying, and Rancimat. Tert-butylhydroquinone (TBHQ) and Butylated hydroxytoluene (BHT) were used as comparison compounds. Both Rancimat and deep-frying tests demonstrated that DMTC was the strongest antioxidant, and TBC also had stronger antioxidant activity than Cur. In the DPPH assay, DMC showed the highest scavenging activity, followed by DMTC, TBHQ, Cur, and TBC. DMTC and TBC can be potentially used as strong antioxidants in food industry, especially for frying, baking, and other high temperature food processing. DMTC is the strongest antioxidant in oil to our knowledge.

High Level of Uric Acid Promotes Atherosclerosis by Targeting NRF2-Mediated Autophagy Dysfunction and Ferroptosis.

Atherosclerotic vascular disease (ASVD) is the leading cause of death worldwide. Hyperuricemia is the fourth risk factor for atherosclerosis after hypertension, diabetes, and hyperlipidemia. The mechanism of hyperuricemia affecting the occurrence and development of atherosclerosis has not been fully elucidated. Mononuclear macrophages play critical roles in all stages of atherosclerosis. Studies have confirmed that both hyperuricemia and ferroptosis promote atherosclerosis, but whether high level of uric acid (HUA) promotes atherosclerosis by regulating ferroptosis in macrophages remains unclear. We found that HUA significantly promoted the development of atherosclerotic plaque and downregulated the protein level of the NRF2/SLC7A11/GPX4 signaling pathway in ApoE−/− mice. Next, we evaluated the effect of HUA and ferroptosis inhibitor ferrostatin-1 (Fer-1) treatment on the formation of macrophage-derived foam cells. HUA promoted the formation of foam cells, decreased cell viability, and increased iron accumulation and lipid peroxidation in macrophages treated with oxidized low-density lipoprotein (oxLDL); these effects were reversed by Fer-1 treatment. Mechanistically, HUA significantly inhibited autophagy and the protein level of the NRF2/SLC7A11/GPX4 signaling pathway. Fer-1 activated autophagy and upregulated the level of ferroptosis-associated proteins. Moreover, an NRF2 inducer (tertbutyl hydroquinone (TBHQ)) and autophagy activator (rapamycin (RAPA)) could reverse the inhibitory effect of HUA on foam cell survival. Our results suggest that HUA-induced ferroptosis of macrophages is involved in the formation of atherosclerotic plaques. More importantly, enhancing autophagy and inhibiting ferroptosis by activating NRF2 may alleviate HUA-induced atherosclerosis. These findings might contribute to a deeper understanding of the role of HUA in the pathogenesis of atherosclerosis and provide a therapeutic target for ASVD associated with hyperuricemia.

Influence of irradiation and addition of antioxidants on the oxidation stability of Jatropha, Pongamia and Tectona Grandis biodiesels

Biodiesel is chemically an ester molecule; there is every possibility that in the presence of air or oxygen, it will be hydrolysed to alcohol and acid. The oxidation of the biodiesels in an ambient air environment leads to deterioration, which diminishes their prospects as mainstream fuel due to their lesser strength against oxidation. The present work reports the oxidation stability of Jatropha biodiesel and Pongamia biodiesel when exposed to sunlight and ultraviolet (UV) irradiation for up to 10 h and 30 days, respectively. The experimentation was further extended with novel biodiesel, Tectona Grandis biodiesel. The different synthetic antioxidants: Butylated hydroxyanisole, Butylated hydroxytoluene, and Tert-butyl hydroquinone (TBHQ) were added to the biodiesel to observe their impact along with varying storage ambiance. The experimental results reveal that exposure to UV and sunlight prompted the oxidation process and the addition of antioxidants is functional to beat the negative influence of irradiation.

Inhibitory effect of antioxidants on key off-odors in French fries and oils and prolong the optimum frying stage

The flavor formation of fried food experienced an optimum stage, fried food obtained more desirable flavor during this stage. In order to improve the flavor of French Fries (FFs), the optimum stage was prolonged by adding several antioxidants (tert-butyl hydroquinone (TBHQ), L-ascorbyl palmitat (L-ap), and rosemary) to the frying soybean oil (SO). The results of sensory evaluation showed that antioxidants had an effect on prolonging the optimum stage. Compared with the control group, the optimum stage of SO added with TBHQ, L-ap and rosemary was prolonged by 25%, 50% and 25%, respectively. Furthermore, antioxidants can effectively inhibit the degradation of some desirable compounds (e. g. (E, E)-2,4-decadienal) and reduce the generation of off-flavor (hexanal, hexanoic acid, heptanoic acid, octanoic acid, and nonanoic acid) during frying. Among them, the TBHQ performed best on inhibiting the increase of total polar compounds, acid value and p-Anisidine value, besides, it had the best effect on reducing the degradation of (E, E)-2,4-decadienal and inhibiting the generation of saturated aldehydes, especially the hexanal. The L-ap showed better abilities to inhibit the generation of off-flavor acids. This study can provide a basis for the effects of different antioxidants in prolonging the optimum stage and inhibiting the off-flavor.

Bright green emission non-conjugated polymer dots: pH trigged hydrogel for specific adsorption of anionic dyes and visual detection of tert-butylhydroquinone

In recent years, non-conjugated polymer dots (PDs) have attracted considerable interests due to their fundamental importance and potential applications in diverse areas. Herein, we synthesized the green emissive non-conjugated PT PDs with polyethyleneimine (PEI) and tetrakis(hydroxymethyl)phosphonium chloride (THPC) as precursors in one-pot at room temperature with the quantum yield at 25%. Surprisingly, PT PDs solutions could be transformed to hydrogels by pH alteration. By characterization, PT PDs hydrogels performed porous structure with large surface area and positively charged functional groups. Anionic dyes could be easily adsorbed into PT PDs hydrogels through multiple electrostatic interactions. In addition, PT PDs could specifically detect tert-butylhydroquinone (TBHQ) with a low detection limit (27 µM), suggesting their high sensitivity. More importantly, the developed method was successfully applied the detection of TBHQ in the peanut oil, implicating their practical application.

Biomimetic metalloporphyrin oxidase modified carbon nanotubes for highly sensitive and stable quantification of anti-oxidants tert-butylhydroquinone in plant oil

This study constructed a novel biomimetic enzyme electrochemical biosensor based on tetraphenyl metalloporphyrins functionalized multi-walled carbon nanotubes (MWCNTs). The effect of central metal ions on the catalytic activity of tetraphenyl metalloporphyrin biomimetic enzyme was investigated. It was found that the change of central metal ions had a significant effect on the catalytic performance of metalloporphyrin and Zinc(II) tetraphenylporphyrin (ZnTPP) had the most excellent catalytic property. The electrochemical behaviors of tert-butylhydroquinone (TBHQ) on ZnTPP/MWCNTs modified electrode were investigated. It was found that the redox peak current was increased significantly, which was attributed to the redox peak current to the electrocatalytic activity of ZnTPP and the synergistic effect between ZnTPP and MWCNTs. A strong linear relationship was shown in the concentration range of 0.01 to 1000 μM. This electrochemical sensor also had excellent repeatability, storage, and interference resistance. This work provided a simple and sensitive method for the determination of TBHQ.

An Environmentally Friendly Antioxidant Foamed Gel for Inhibiting Spontaneous Combustion of Coal

ABSTRACT Coal spontaneous combustion can cause serious coal mine fire and gas explosion. In order to overcome the problem that the effect of existing materials to inhibit coal spontaneous combustion is reduced at high temperature and some environmental protection problems of materials, this study developed an effective, green and environmental protection antioxidant foamed gel (AFG). Modified sodium polyacrylate, konjac glucomannan, sodium dodecyl sulfate, sodium alpha-olefin sulfonate, modified silicone polyether microemulsion, montmorillonite, and tert-butyl hydroquinone were selected as raw materials. A single factor experiment was conducted to determine the appropriate adding proportions for each component. Then, the optimal proportion for the five components were fitted and verified by response surface analysis. The structures of the samples were characterized, and their properties were compared and tested. The fluidity, water loss, and thermogravimetry experiments demonstrated that the effect of AFG was excellent. In the experiment of in situ diffuse reflectance Fourier transform infrared spectroscopy, the AFG inhibition reaction was verified. Finally, combined with the structural characteristics of the AFG, the following inhibiting mechanisms were confirmed: AFG adhered to the coal surface and blocked the coal–oxygen contact; the antioxidant component slowed down chemisorption and the chemical reactions; AFG interrupted the free radical chain reaction.

Tert-butylhydroquinone prevents neuroinflammation and relieves depression via regulation of NLRP3 signaling in mice

Depression is a common psychiatric disorder, which seriously affects people’s health and quality of life. Current treatments, which mainly focus on neurotransmitter levels, are not effective in many patients. Recent studies have shown that neuroinflammation has certain correlation with the pathogenesis of depression. Tert-butylhydroquinone (TBHQ) is an antioxidant with an anti-inflammatory effect. The present study evaluated the effects of TBHQ on the improvement of depression-like behaviors induced by lipopolysaccharide (LPS) in mice and its possible mechanism. Behavioral test results showed that TBHQ treatment could significantly improve the depression-like behaviors of mice. Western blot results showed that TBHQ treatment inhibited the protein expression of NLRP3, Caspase-1, IL-1β, and IL-18, which induced by LPS. Immunofluorescence staining results showed that TBHQ treatment inhibited the activation of microglia induced by LPS. These results suggested that, by inhibiting LPS-induced neuroinflammation and microglia activation, TBHQ could effectively improve LPS-induced inflammation-related depression-like behavior through modulating the NLRP3 signaling pathway.

Nano-encapsulation of sweet basil essential oil based on native gums and its application in controlling the oxidative stability of Kilka fish oil

In line with the application of green techniques in the recovery of bioactive compounds, this research study aimed to evaluate the efficiency of supercritical Co2 and water distillation in the extraction of sweet basil essential oil. In addition, the effect of wall material made of native gums as well as Lepidium sativum (LS), Lepidium perfoliatum (LP), and a combination of both (LP/LS), following freeze-drying method, on Nano-emulsion properties of encapsulated sweet basil essential oil was evaluated. The encapsulation efficiency (EE%), particle size, polydispersity index, zeta potential (ζ), scanning electron microscopy, viscosity, Brix, pH, density, humidity, water activity, and Fourier transform infrared of nano encapsulated powder were studied. The EE of supercritical fluid was significantly higher (6.3%) in contrast to the distillation of water (1.4%). To study the oxidative stability, essential oil of sweet basil in free mode 1%, 5% and 20% (w/w) and in the encapsulated form 20% (w/w) added to Kilka oil and compared with tert-butylhydroquinone (TBHQ) as synthetic antioxidants at 0.01% (w/w). The results showed that sweet basil essential oil had antioxidant activity and reduced the oxidation process. Unlike free essential oil, nanocapsule essential oil (especially with a coating of LP gum) showed better antioxidant activity comparable to that of TBHQ. Thus, encapsulated sweet basil essential oil with LP gum showed promising results in retarding the fish oil oxidation, which can be introduced as a novel natural antioxidant specifically in emulsion, based food systems.

Stabilisation of Soybean Oil with Pod Coat Extracts of Cowpea (Vigna unguiculata)

Background: In edible oil processing industry the main reason of lipid deterioration is oxidation. The inclusion of antioxidants is required to preserve colour, flavour and to prevent vitamin destruction. In recent years the discovery of safe antioxidants of plant origin have increased conspicuously and they have been considered as better alternative than synthetic antioxidants such as tert-butyl hydroquinone, butylated hydroxyanisole, propyl gallate etc. This study is an attempt to investigate pod coats of cowpea as potential source of natural antioxidants and to appraise their efficacy for stabilizing soybean oil. Methods: In the laboratory investigation during 2015-2018 the efficacy of cowpea pod coat extracts in stabilizing soybean oil during accelerated storage has been studied. Pod coats of cowpea were extracted with three solvents (acetone, ethyl acetate and chloroform). Soybean oil samples were stabilised by adding different pod coat extracts at 1000 and 2000 ppm concentration. Result: Our investigation allowed us to conclude that rate of oxidative degradation of soybean oil was the lowest in the sample treated with acetone extract (2000 ppm).

An ultrafine ZnO/ZnNi2O4@porous carbon@covalent-organic framework for electrochemical detection of paracetamol and tert-butyl hydroquinone

An electrochemical sensor based on ultrafine ZnO/ZnNi2O4 @porous carbon@covalent-organic framework (COF) was constructed for the detection of paracetamol (PA) and tert-butylhydroquinone (TBHQ). First, Ni-doped zeolite imidazolium framework-8 (ZIF-8) was used as pyrolysis precursor to obtain porous carbon-encapsulated ultrafine ZnO/ZnNi2O4 (ZnO/ZnNi2O4 @porous carbon) with a specific surface area of about 1130 m2 g−1. Then, COFTM was grew on ZnO/ZnNi2O4 @porous carbon by amine-aldehyde condensation reaction between 3,5-triformylphloroglucinol (TPF) and 1,3,4,6,7,9,9b-heptaazaphenalene-2,5,8-triamine (ML) around the ZnO/ZnNi2O4 @porous carbon. The ultrafine ZnO/ZnNi2O4 nanoparticles were evenly dispersed in porous carbon. The N,O-rich COFTM was used as the outer shell to enhance the stability of ZnO/ZnNi2O4 @porous carbon and simultaneously could enrich the PA/TBHQ and improve selectivity of sensor. The electrochemical sensor based on the core-shell structured nanocomposite exhibited wide linear ranges of 48.5 nM-130 μM and 47.85 nM-130 μM for detecting PA and TBHQ. The PA and TBHQ sensor also showed good stability, selectivity and sensitivity. This work not only provides a new method for the detection of drug molecules and additives in food but also gives an idea to improve the selectivity and stability of electrochemical sensor.

Study of Rapid HPLC Method for the Determination of Antioxidants in Foods, and Standard Solution Stability during Storage

In this study, we simultaneously determined three antioxidants, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and tert-butylhydroquinone (TBHQ), using HPLC equipped both with a photodiode array detector and a fluorescence detector in 25 minutes per sample. Due to the combined use of the two detectors, we could achieve improved target selectivity. Further, quantification at the specific wavelengths for each target substance particularly increased BHT detection sensitivity. This approach enabled us to avoid repeated measurements during daily inspections. Furthermore, detections were performed using LC-MS/MS instead of GC-MS to overcome the problem of helium gas shortage.In addition, we investigated antioxidant stability in standard solutions during storage. Although TBHQ was stable in methanol with ascorbic acid at -20℃, ascorbic acid storage has possibility to lead to decrease in BHT and BHA concentrations. We recognized that the mixture of BHT and BHA dissolved in methanol at 4℃ and that of BHT, BHA and TBHQ dissolved in methanol with ascorbic acid at -20℃ were suitable for about one year.

Evaluation of oxidation stability and engine behaviors operated by Prosopis juliflora biodiesel/diesel fuel blends with presence of synthetic antioxidant

This experimental study focuses on analyzing the oxidation stability, engine performance, and combustion characteristics of Prosopis juliflora biodiesel blended with synthetic antioxidants. In the first stage, four synthetic antioxidants such as Butylated Hydroxy Toluene, Propyl Gallate, Pyrogallol, Tert-Butyl-Hydroquinone (TBHQ) were selected to evaluate their oxidation stability. Resultantly, TBHQ was the best synthetic antioxidant with the highest induction period, corresponding to 10.19 h, among the above-mentioned synthetic antioxidants while it was added to the B20 blend (20% Prosopis juliflora biodiesel/80% diesel fuel). In the second stage, different concentrations of TBHQ (500, 1000, and 1500 ppm) were added to B20 sample for the test of performane, combustion, and emission characteristics of a 4-stroke diesel engine. Indeed, adding TBHQ to the B20 sample increased brake thermal efficiency and emissions of CO and HC, while it reduced brake-specific fuel consumption and emissions of NOx and CO2. Furthermore, it could be observed a decrease in peaks of in-cylinder pressure and heat release rate, and an increase in mass fraction burned as adding TBHQ. In general, the use of TBHQ antioxidant-included biodiesel for diesel engines could improve engine performance and emission, and enhance the fuel' oxidation stability.

Ligand-independent activation of AhR by hydroquinone mediates benzene-induced hematopoietic toxicity

Although it has been well recognized that benzene exposure can cause hematopoietic disorders such as aplastic anemia and leukemia, the underlying molecular mechanism remains to be fully understood. Emerging evidence indicated that aryl hydrocarbon receptor (AhR) plays important roles in hematopoietic and immune systems. This study investigated the activation of aryl hydrocarbon receptor (AhR) by hydroquinone (HQ) and its role in HQ-induced DNA damage and apoptosis in cultured human lymphocytes (JHP cells). We also investigated the effect of ROS on AhR activation and functions in JHP cells exposed to HQ with and without regulator including N-acetyl-l-cysteine (NAC), a potent antioxidant, and tert-butylhydroquinone (TBHQ), a Nrf2 activator. Results showed that HQ can cause oxidative stress, DNA damage and apoptosis. Pretreatment of an AhR antagonist (CH223191) can significantly increase the cell survival and mitigate HQ-induced toxicities such as DNA damage and apoptosis. We found that HQ can obviously increase expressions of total protein of AhR and prompt nuclear translocation compared to the control group. Interestingly, NAC can block HQ-induced AhR activation and DNA damage and apoptosis. Conclusively, our results indicated that HQ toxicity is mediated by AhR which is in turn regulated by ROS generated by HQ. The interaction between AhR and ROS drive and amplify the hematopoietic toxicity of HQ. This study provided new insights of mechanism and potential targets for the prevention and treatment to benzene-induced hematopoietic toxicity.

Evaluating the Potential of Phytochemicals as Natural Substitute for Synthetic Antioxidant: A Review

This study aimed at investigating the antioxidant potential of flavonoids as a subgroup of polyphenols and ultimately entirely and partially substitute the synthetic antioxidant with natural them. All relevant databases were searched for the terms including 'phytochemical', polyphenol', 'flavonoid', 'natural additive', as well as 'antioxidant activity' combined with in vivo and in vitro phrases. Free radicals are among the damaging factors to macromolecules. The oxidative reaction caused by these radicals is one of the reasons for food spoilage, which causes unpleasant odor, loss of taste, damaged tissue and appearance, and loss of nutritional value of exposed material. The common antioxidants employed in foods include Butylated hydroxytoluene (BHT), Butylated hydroxyanisole (BHA), Tert-butyl hydroquinone (TBHQ), and Propyl gallate (P.G.). Synthetic antioxidants have adverse effects such as causing mutation and carcinogenicity in the human body despite their high performance; hence, many studies have been carried out on replacing them with natural antioxidants. Phytochemicals and a widespread group of them known as polyphenols possess a high antioxidant activity. A major subset of polyphenols, Flavonoids, are secondary metabolites in plants with many applications. These compounds are potential antioxidants because of their capabilities, such as scavenging the free radicals donating hydrogen atoms, electrons, and chelate metal cations. The antioxidant mechanism of action of flavonoids is transferring hydrogen toward free radicals. Accordingly, the more the flavonoid structure makes the hydrogen transfer faster and easier, the more the flavonoid's antioxidant power will be. Therefore, the antioxidant activity of the flavonoids with hydroxy groups in their structure is higher among the different flavonoids. Besides health promotion and some disease prevention effects, various in vitro studies have shown that flavonoids possess a high antioxidant activity that is competitive with synthetic antioxidants. However, to make it commercially available, cheaper and high-performance extraction methods of flavonoids will have to be developed.

Spray‐Drying, Oil Blending, and the Addition of Antioxidants Enhance the Storage Stability at Room Temperature of Omega‐3‐Rich Microcapsules Based on Chia Oil

AbstractChia oil (CO) has gained popularity given its α‐linolenic acid content (around 60%). Nonetheless, the susceptibility of polyunsaturated fatty acids toward oxidation represents a challenge for incorporating CO in different products, which justifies the need for exploring stabilization methods. To the best of the authors' knowledge, no reports about powders based on chia oil blends are published. Therefore, the objective of this research is to evaluate the stability at room temperature of microencapsulated CO blends [with virgin sesame (VSO) and wheat germ (WGO) oils] and microencapsulated CO with the addition of tert‐butylhydroquinone (TBHQ). Spray‐drying yielded powders with a better encapsulation efficiency, flowability, and stability, compared with freeze‐drying. After a storage test performed during 3 months, the highest hydroperoxide content (>100 meq.O2 kg−1 oil) is observed for the microencapsulated CO/WGO 80/20 blend, despite its α and β‐tocopherol contents and its antioxidant activity (>90% inhibition of DPPH radical). Notwithstanding, bulk and microencapsulated CO‐TBHQ, CO/VSO 80/20, and 20/80 showed hydroperoxide contents <8 meq.O2 kg−1 oil. By the end of the test, the highest induction period is observed for the microencapsulated CO/VSO 20/80 blend (19.85 ± 0.18 h). Finally, the drying method and the core formulation greatly affect the stability of microcapsules.Practical Applications: Addition of antioxidants, oil blending and microencapsulation are technological solutions for the preservation of omega‐3‐rich oils, which are popular among healthy food consumers. This research studies and compares the microencapsulation processes by spray or freeze‐drying in order to preserve chia oil blends (with virgin sesame and wheat germ oils) and chia oil with the addition of antioxidants, thereby taking the advantages of the three technological solutions mentioned above. Stable omega‐3‐rich powders, with a higher oxidative stability than pure chia oil, can be obtained as ingredients for the food industry. This ultimately allows the incorporation of the oil into different food products developed to satisfy specific market tendencies.

Electrochemical determination of several biofuel antioxidants in biodiesel and biokerosene using polylactic acid loaded with carbon black within 3D-printed devices.

Low oxidation stability is the main drawback of biodiesels and biokerosenes that is overcome by using antioxidants, which can be combined due to synergistic effects. This paper demonstrates that 3D-printed electrochemical devices can be applied to biofuel electroanalysis, including the monitoring of oxidation stability by quantifying the antioxidant content in biofuels. Fabrication requires 3D-printed acrylic templates at which a polylactic acid (PLA) filament with conducting carbon-black filling sensors is extruded by a 3D pen. The antioxidants butyl hydroxyanisole (BHA) and tert-butylhydroquinone (TBHQ) are the most employed additives in biodiesel production, and thus, their electrochemical behavior was investigated; 2,6-ditertbutylphenol (2,6-DTBP) was included in this investigation because it is commonly added to biokerosenes. The electrochemical surface treatment of the 3D-printed electrodes improved the current responses of all antioxidants; however, the electrochemical oxidation of TBHQ was clearly more affected by an electrocatalytic action shifting its oxidation towards less positive potentials (~200 mV), which resulted in a better separation of TBHQ and BHA oxidation peaks (+0.4 and +0.6 V vs Ag|AgCl, respectively). The oxidation of 2,6-DTBP occurred at more positive potentials (+1.2 V vs Ag|AgCl). The simultaneous determination of TBHQ and BHA by differential-pulse voltammetry resulted in linear responses in the range 0.5 and 175 μmol L-1 with limits of detection and quantification of 0.15 μmol L-1 and 0.5 μmol L-1, respectively. The presence of Fe3+, Cu2+, Pb2+, Mn2+, Cd2+, and Zn2+, even in high concentrations, did not interfere in the determination of TBHQ and BHA. The determination of 2,6-DTBP in biokerosene was achieved by cyclic voltammetry. All relative standard deviations (RSD) were lower than 6.0 %, indicating adequate precision of the methods. Spiked biofuel samples were analyzed (after dilution in electrolyte) and recovery values between 85 and 120% were obtained, which indicates absence of sample matrix effects.