Oxidation Products Research Articles

Investigation of process parameters for eco-friendly indigo dyeing of cotton fabric with reducing sugars

Purpose The application of indigo dyes in the denim industries has been criticised due to the introduction of non-renewable oxidation products into the environment. Previous studies have investigated that reducing sugars can be used as green alternatives to sodium dithionite in the indigo dyeing of cotton fabric owing to their reduced and stable redox potential in the dye bath. The purpose of this study was to dye denim cotton fabric with indigo dye using various reducing sugars and alkalis. The use of sucrose and potassium hydroxide (KOH) for indigo dyeing has been explored for the first time. Design/methodology/approach A mixed factorial design with four variables including alkali, pH, number of dips and type of reducing sugar at different levels was studied to identify a significant correlation between the effect of these variables on the colour strength and fastness properties of the dyeings. Findings Investigations were made to examine the significant factors and interactions of the selected responses in the eco-friendly dyeing method. This process has the potential to reduce the load of sulphite and sulphate generated in the dyebath due to the use of a conventional reducing agent, sodium dithionite. The colour strength of the dyeing reduced with fructose was found to be better than other reducing sugars and significantly influenced by the number of dips, pH levels and the interaction between pH and reducing sugars. Using fructose for indigo dyeing with two dips at a pH of 11.5, using KOH as an alkali, results in higher colour strength values. The fastness properties of the indigo-dyed sample with reducing sugars ranging from fair to good or good to excellent. Specifically, colour change receives a rating of grey scale 3–4, staining 4–5, dry rubbing 4 and light fastness 3–4. These assessments hold true across various factors such as the type of reducing sugar, alkali, pH and the number of dips. The optimised parameters leading to improved colour strength and fastness properties are also discussed. Originality/value This dyeing technique is novel and a green alternative to dithionite denim dyeing. This process is found to be useful for indigo dyeing of denim fabric leading to reduced and stable redox potential in the dyebath and acceptable colour strength of the dyed fabric.

Use of mushrooms as antioxidants in a lipid oxidation model under indirect and direct oxidation tests: ethanolic extracts of Ganoderma resinaceum and Phlebopus bruchii.

Foods contain lipids that are easily susceptible to oxidation, which can modify their sensory properties. Although these compounds provide characteristic flavours and odours, there are also unwanted compounds, such as volatile secondary oxidation products, representing a recurring problem for both the industry and consumers. Synthetic antioxidants are often employed to prevent this but their chronic consumption can be detrimental to human health. The present study evaluates the antioxidant potential of ethanolic extracts from Ganoderma resinaceum and Phlebopus bruchii using an accelerated oxidation test. The composition profile of the extracts was investigated, identifying the presence of tryptophan, quinic acid, caffeic acid and 3,4-dihydroxyphenylglycol-phenolic acid. The antioxidant capacity of the extracts was compared with that of butylated hydroxytoluene (BHT) in sunflower oil that was oven-heated at 60 °C. Chemical (peroxide value, p-anisidine value and conjugated dienes) and volatile (2-octenal, 2-heptenal and 2,4-decadienal) indicators were measured over 28 days. The peroxide value decreased for both extracts at a similar level to that of BHT 0.02% w/w, and conjugate dienes decreased in the presence of G. resinaceum 0.1% w/w. Meanwhile, p-anisidine exhibited a slightly greater decrease for P. bruchii 0.1% w/w than for BHT. The sample with 0.1% w/w of extracts showed a reduction in volatile secondary oxidation compounds, indicating significant antioxidant activity. Based on these results, both extracts could be proposed as potential antioxidants in foods with a high lipid content. © 2024 Society of Chemical Industry.

Fluorescence Spectroscopy Based Characterization of Flaxseed Oil.

Fluorescence spectroscopy has been employed for the compositional analysis of flaxseed oil, detection of its adulteration and investigation of the thermal effects on its molecular composition. Excitation wavelengths from 320 to 420nm have been used to explore the valued ingredients in flaxseed oil. The emission bands of flaxseed oil centred at 390, 414, 441, 475, 515 and 673/720 nm represent vitamin K, isomers of vitamin E, carotenoids and chlorophylls, which can be used as a marker for quality analysis. Due to its high quality, it is highly prone to adulteration and in this study, detection of its adulteration with canola oil is demonstrated by applying principal component analysis. Moreover, the effects of temperature on the molecular composition of cold pressed flaxseed oil has been explored by heating them at cooking temperatures of 100, 110, 120, 130, 140, 150, 160, 170 and 180°C, each for 30min. On heating, the deterioration of vitamin E, carotenoids and chlorophylls occurred with an increase in the oxidation products. However, it was found that up to 140°C, flaxseed oil retains much of its natural composition whereas up to 180 oC, it loses much of its valuable ingredients along with increase of oxidized products.

Mineralogy and a New Fertility Index of Alunite in the Fanshan Lithocap, Luzong Basin, Anhui Province, China

Alunite is used as a representative mineral for indicating deposits in lithocaps, and lithocaps are generally related to the porphyry–(high-sulfidation) epithermal mineralization system. The study of alunite is of theoretical and exploration significance for prospecting potential underlying porphyry and epithermal deposits. Studies on alunite geochemistry have made breakthroughs, but there is little research on alunite mineralogy, for example, using scanning electron microscopy (SEM) images, differential thermal analysis (DTA), and Fourier-transform infrared spectroscopy (FT-IR). This study mainly focuses on alunite micromorphological characteristics, weight loss changes with temperature, and ionic group structure, aiming to identify the relationship between these features and indications for prospecting. The Fanshan lithocap is located in the northwest part of the Luzong basin, Anhui province of China, and it can potentially be used for exploring porphyry and epithermal deposits. Fanshan alunite is formed in two stages with three types of alunite. IA alunite is formed in the early hydrothermal stage and replaces felsic minerals in the Zhuanqiao Formation, IB alunite is formed in the later hydrothermal stage and fills in open spaces with bladed particles, and II alunite is the product of pyrite oxidation and reaction with other minerals in the supergene stage. Alunite electron microprobe data and energy-dispersive spectroscopy data further confirm temperature decreases with hydrothermal evolution, and the presence of a high-sulfidation epithermal system in the Luzong basin. Aside from the forming environment, SWIR, and geochemistry of alunite, there are other indication indexes; for example, the larger peak values at 3480 cm−1 and smaller peak values at 1080 cm−1 in FT-IR spectra and the deeper exothermic valleys at 750 °C and steeper weight loss slopes in the DTA curve suggest a favorable formation environment for alunite and provide valuable indications for deposit exploration and assessments of mineralization potential.

Cellulosic fibers spun from stabilized imidazolium ionic liquids: identification of chromophores in the fibers after accelerated ageing

AbstractCellulosic fibers spun from 1,3-dialkylimidazolium ionic liquids are effectively stabilized against cellulose degradation by the addition of antioxidants, but this protective effect comes at the expense of chromophore generation from the degradation products of the stabilizers. In this study, we identified the oxidation and degradation products of four natural antioxidants, α-tocopherol, N-methyl-α-tocopheramine, propyl gallate, and hydroxytyrosol, formed upon accelerated ageing of the fibers. Ageing was performed according to standard protocols under either dry or moist conditions and the extraction was done with supercritical carbon dioxide. Chromophore formation in spinning dope, upon dry ageing and moist ageing were compared. In total, 16 different oxidation/degradation products were isolated, their structure confirmed by comprehensive analytical characterization with full NMR resonance assignment in the 1H and 13C domains as well as by comparison with authentic samples, and their formation pathways discussed. Knowledge of the chemical structures of the degradation products originating from the stabilizers now provides a good starting point for optimization of the fiber bleaching stage. Graphical abstract

Corrosion behavior of Al4SiC4/SiC ceramics exposed to molten calcium‐magnesium‐alumino‐silicate at 1350°C in air

AbstractAl4SiC4 shows excellent heat resistance, thermal shock resistance, machinability, and oxidation resistance. We focused on Al4SiC4‐based ceramics with SiC as a non‐oxide matrix for ceramic matrix composites for aircraft jet engines. In this study, monolithic Al4SiC4 and Al4SiC4/SiC ceramics were fabricated by hot‐pressing, and a corrosion test against molten calcium‐magnesium‐alumino‐silicate (CMAS) was conducted at 1350°C for 12–100 h in air, and their corrosion behavior was investigated. Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy results revealed that severe damage was not observed at the interface between CMAS and the samples after the CMAS corrosion test. The recession of Al4SiC4‐100, ‐10, and SiC‐100 after corrosion for 100 h was 80–90 µm, and that of Al4SiC4‐50 was the highest of all samples and the value was 130 µm. The dissolution behavior of the oxidation layer into molten CMAS via a corrosion reaction was dependent on the composition of both the sample and the oxidation layer, the thickness, and the microstructure of the oxidation layers. The dominant mechanism of reaction between CMAS and Al4SiC4‐100, ‐90, and ‐50 samples was concluded to be the dissolution of the oxidation products, while in SiC‐100 and Al4SiC4‐10 samples, the dominant reaction was determined to be direct corrosion of the surface with CMAS.

Longevity Spinach (Gynura procumbens) Ameliorated Oxidative Stress and Inflammatory Mediators in Cisplatin-Induced Organ Dysfunction in Rats: Comprehensive in vivo and in silico Studies.

This study focused to assess the efficacy of Gynura procumbens (GP) leaf extract against cisplatin (CP)-induced hepatorenal complications in Wister albino rats. Additionally, it aims to detect polyphenolic compounds using high-performance liquid chromatography with diode-array detection (HPLC-DAD). The rats were treated intraperitoneally with CP (7.5 mg/kg) to mediate hepatorenal damage. They were then treated with GP extract (75 and 150 mg/kg, P.O.) for 7 consecutive days. Although GP extract significantly ameliorated CP-mediated hepatorenal biomarkers like alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, and blood urea nitrogen (BUN) levels in a dose-dependent manner, GP extract at 150 mg/kg dose normalized hepatorenal biomarkers ALP (45.11 U/L), ALT (34 U/L), AST (29 U/L), creatinine (10.3 mg/dl) and BUN (11.19 mg/dl) while comparing to control and disease group. Similarly, though it significantly reduced CP-induced oxidative stress inducers, including nitric oxide (NO) and advanced oxidative protein products (AOPP), higher dose (150 mg/kg) exhibited better activity in reducing NO (281.54 mmol/gm tissue in liver and 52.73 mmol/gm tissue in the kidney) and AOPP (770.95 mmol/mg protein in liver and 651.90 mmol/mg protein in the kidney). Besides, it showed better enhancement in the antioxidant enzymes superoxide dismutase, and glutathione levels at a higher dose (150 mg/kg). Histopathological studies showed that CP caused collagen accumulation in the liver and kidney tissues. GP extract drained the collagen mass and acted against hepatorenal damage. Ellagic acid, gallic acid, quercetin hydrate, kaempferol, and rutin hydrate were revealed in GP extract. In-silico modelling showed good docking scores of the polyphenolic compounds with molecular targets including CYP4502E1, NF-κB, caspase-3, and TNF-α. GP could be an effective therapeutic option for management of anticancer drugs' complications like CP-induced organ damage, although clinical studies are required to establish herbal formulation.

Minor Hydroxylated Triterpenoids Produced in Engineered Yeast by the Enzymes OSC and CYP716s from the Plant Enkianthus chinensis and Their Anti-Inflammatory and Hepatoprotective Activities.

Triterpenoids are a type of specialized metabolites that exhibit a wide range of biological activities. However, the availability of some minor triterpenoids in nature is limited, which has hindered our understanding of their pharmacological potential. To overcome this limitation, heterologous biosynthesis of triterpenoids in yeast has emerged as a promising and time-efficient production platform for obtaining these minor compounds. In this study, we analyzed the transcriptomic data of Enkianthus chinensis to identify one oxidosqualene cyclase (EcOSC) gene and four CYP716s. Through heterologous expression of these genes in yeast, nine natural pentacyclic triterpenoids, including three skeleton products (1-3) produced by one multifunctional OSC and six minor oxidation products (4-9) catalyzed by CYP716s, were obtained. Of note, we discovered that CYP716E60 could oxidize ursane-type and oleanane-type triterpenoids to produce 6β-OH derivatives, marking the first confirmed C-6β hydroxylation in an ursuane-type triterpenoid. Compound 9 showed moderate inhibitory activity against NO production and dose-dependently reduced IL-1β and IL-6 production at the transcriptional and protein levels. Compounds 1, 2, 8, and 9 exhibited moderate hepatoprotective activity with the survival rates of HepG2 cells from 61% to 68% at 10 μM.

Exploring the impact of malondialdehyde and 4-hydroxy-2-nonena on myofibrillar protein structure: A proteomic analysis

In this investigation, the impacts of malondialdehyde (MDA), 4-hydroxy-2-nonena (HNE), and their combinations on the structural characteristics of myofibrillar proteins (MP) were examined using endogenous fluorescence, Fourier transform infrared spectrum (FTIR) and Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE). The potential binding mechanisms were also explored using LC-MS/MS and proteomics techniques. The findings indicated that various reactive carbonyl compounds (RCCs) displayed distinct oxidation performances in the oxidation of myofibrillar proteins. Samples containing HNE (HMP and MHMP groups) exhibited a more pronounced ability to oxidize MP than those containing MDA, as evidenced by their higher carbonyl content and lower sulfhydryl content. The MHMP group demonstrated the greatest surface hydrophobicity and Schiff base content but the lowest fluorescence intensity, suggesting that MDA and HNE synergistically altered MP conformation. Moreover, the alteration by RCCs notably modified the secondary structure of MP. Among these, HMP triggered the unfolding of MP molecules, resulting in the lowest α-helix and highest β-sheet ratio. The SDS‒PAGE results suggested that MDA oxidation promoted the crosslinking of MP molecules. At the same time, HNE caused the degradation of MP, as indicated by the decrease in the intensity of the high-molecular-weight bands. Proteomic analysis suggested that lysine residues distributed in the tail region of myosin were the main binding sites for MDA, whereas HNE preferentially modified methionine located at the myosin head. Additionally, HNE-induced protein degradation dominated RCC-induced oxidation reactions. These findings provide deeper insights into the mechanisms underlying quality changes induced by lipid oxidation products in MP-based food systems.

Chromophores in spinning dopes of cellulose and imidazolium ionic liquids

AbstractSpinning of cellulose dissolved in 3-alkyl-1-methylimidazolium ionic liquids is a current approach to manmade cellulosic fibers. To curb cellulose degradation in the dope, stabilizers have to be used. Generation of chromophores in the dope and the resulting fibers is unavoidable, with most of the discoloration resulting from the employed antioxidants. In the present work, the chemical structures of the chromophores derived from the most common “green” stabilizers currently used, namely propyl gallate (a gallic acid derivative), hydroxytyrosol (and antioxidant from olives), and tocopheramines (vitamin E derivatives), were elucidated by a combination of analytical techniques and final confirmation by comparison with independently synthesized samples. While most compounds are oxidation and rearrangement products of the antioxidants themselves, coupling products with the ionic liquid´s imidazolium cations were also found. Identification of the colored compounds is a critical issue for both the optimization of fiber bleaching steps and solvent purification/recovery in the spinning process. Now that the nature of the generated chromophores is known, milder yet more effective bleaching treatments can be developed and solvent purification/recycling can be specifically optimized.

Synergistic oxidative removal of sulfamethoxazole using Ferrate(VI) and peroxymonosulfate

The synergic effect of Ferrate(VI) (Fe(VI)) and peroxymonosulfate (PMS) on sulfamethoxazole (SMX) oxidative removal was investigated in this study. The sulfate radicals (SO4−), generated through Fe(VI)-mediated activation of PMS, have been demonstrated as an effective oxidant for the removal of SMX. However, the scavenging experiments have suggested that various iron species, i.e., Fe(VI), Fe(V), and Fe(IV) play a vital role in facilitating efficient SMX oxidation. pH is a crucial parameter in this system because the involved species, including Fe(VI), PMS, and SMX, have acid-base dissociation points. Accordingly, the optimal pH value for the SMX removal was achieved at pH = 6, and the addition of PMS enhanced the degradation efficiency of Fe(VI) at all pH-operating conditions. Several oxidation products of SMX were identified, including sulfanilamide (SAM), 3-amino-5-methylisoxazole (AMI), and other potentially hydroxylated byproducts. Characterization studies on solid particles collected after the Fe(VI)/PMS treatment revealed structural changes during SMX oxidation, and the potential contributions of Fe2O3 or Fe(OH)3 to the oxidation mechanism were evaluated accordingly. While the removal efficiency in a river matrix was slightly reduced, the presence of inorganic ions had minimal impact on SMX removal, which confirms the high potential of the Fe(VI)/PMS technology to operate in environmentally relevant conditions.

The Composition of Volatiles and the Role of Non-Traditional LOX on Target Metabolites in Virgin Olive Oil from Autochthonous Dalmatian Cultivars

The lipoxygenase pathway has a significant influence on the composition of the volatile components of virgin olive oil (VOO). In this work, the influence of the maturity index (MI) on the activity of the lipoxygenase enzyme (LOX) in the fruits of the autochthonous Dalmatian olive cultivars Oblica, Levantinka and Lastovka was studied. The analysis of the primary oxidation products of linoleic acid in the studied cultivars showed that LOX synthesises a mixture of 9- and 13-hydroperoxides of octadecenoic acid in a ratio of about 1:2, which makes it a non-traditional plant LOX. By processing the fruits of MI~3, we obtained VOOs with the highest concentration of desirable C6 volatile compounds among the cultivars studied. We confirmed a positive correlation between MI, the enzyme activity LOX and the concentration of hexyl acetate and hexanol in cultivars Oblica and Lastovka, while no positive correlation with hexanol was observed in the cultivar Levantinka. A significant negative correlation was found between total phenolic compounds in VOO and LOX enzyme activity, followed by an increase in the MI of fruits. This article contributes to the selection of the optimal harvest time for the production of VOOs with the desired aromatic properties and to the knowledge of the varietal characteristics of VOOs.

Utilization of Flotation Wastewater for Separation of Chalcopyrite and Molybdenite by Selective Surface Passivation

In the flotation separation process of a Cu-Mo-W polymetallic ore, the wastewater from the scheelite cleaning flowsheet contains large numbers of residual flocculants and metal ions, and the separation of chalcopyrite and molybdenite requires a large number of environmentally harmful depressants. Therefore, it is necessary to find new methods to reduce the environmental and cost pressures of wastewater treatment and the use of depressants. In this work, the flotation wastewater from the scheelite cleaning flowsheet for the separation of chalcopyrite and molybdenite by selective surface passivation was investigated for the first time. Flotations of single minerals and artificially mixed minerals with or without immersion pretreatment in the presence and absence of aeration were performed. The results showed that pulp pH had no effect on the flotation of either mineral, and a molybdenite recovery of 93.22% with a chalcopyrite recovery of 10.77% was achieved under the conditions of 10 days of immersion pretreatment with aeration, 350 mg/L of kerosene, and 100 mg/L of MIBC. By combining the electrochemical cyclic voltammetry analysis and characterization by XRD and SEM, the selective surface passivation mechanism of chalcopyrite was discussed, which could be due to the coverage of the insoluble oxidation products, especially jarosite. This work has simultaneously achieved the depressant-free flotation separation of molybdenite and chalcopyrite and the reuse of scheelite flotation wastewater, which is of great significance for environmental protection and cost saving.

Alpha-synuclein interaction with mitochondria is the final mechanism of ferroptotic death induced by erastin in SH-SY5Y cells

Ferroptosis has been characterized as a form of iron-dependent regulated cell death accompanied by an accumulation of reactive oxygen species and lipid oxidation products along with typical morphological alterations in mitochondria. Ferroptosis is activated by diverse triggers and inhibited by ferrostatin-1 and liproxstatin-1, apart from iron chelators and several antioxidants, and the process is implicated in multiple pathological conditions. There are, however, certain ambiguities about ferroptosis, especially regarding the final executioner of cell death subsequent to the accumulation of ROS. This study uses a typical inducer of ferroptosis such as erastin on SH-SY5Y cells, and shows clearly that ferroptotic death of cells is accompanied by the loss of mitochondrial membrane potential and intracellular ATP content along with an accumulation of oxidative stress markers. All these are prevented by ferrostatin-1 and liproxstatin-1. Additionally, cyclosporine A prevents mitochondrial alterations and cell death induced by erastin implying the crucial role of mitochondrial permeability transition pore (mPTP) activation in ferroptotic death. Furthermore, an accumulation of α-synuclein occurs during erastin induced ferroptosis which can be inhibited by ferrostatin-1 and liproxstatin-1. When the knock-down of α-synuclein expression is performed by specific siRNA treatment of SH-SY5Y cells, the mitochondrial impairment and ferroptotic death of the cells induced by erastin are markedly prevented. Thus, α-synuclein through the involvement of mPTP appears to be the key executioner protein of ferroptosis induced by erastin, but it needs to be verified if it is a generalized mechanism of ferroptosis by using other inducers and cell lines.

Advanced remediation in the presence of ferrous iron and carbonate-containing water by oxygen-induced oxidation of organic contaminants

Mechanistic investigations of an environmentally friendly and easy-to-implement oxidation method in the remediation of contaminated anoxic waters, i.e. groundwater, through the sole use of oxygen for the oxygen-induced oxidation of pollutants were the focus of this work. This was achieved by the addition of O2 under anoxic conditions in the presence of ferrous iron which initiated the ferrous oxidation and the simultaneous formation of reactive •OH radicals. The involvement of inorganic ligands such as carbonates in the activation of oxygen as part of the oxidation of Fe2+ in water was investigated, too. The formation of •OH radicals, was confirmed in two different, indirect approaches by a fluorescence-based method involving coumarin as •OH scavenger and by the determination of the oxidation products of different aromatic VOCs. In the latter case, the oxidation products of several typical aromatic groundwater contaminants such as BTEX (benzene, toluene, ethylbenzene, xylenes), indane and ibuprofen, were determined. The influence of other ligands in the absence of bicarbonate and the effect of pH were also addressed.The possibility of activation of O2 in carbonate-rich water i.e. groundwater, may also potentially contribute to oxidation of groundwater contaminants and support other primary remediation techniques.

Multistep Biooxidation of 5-(Hydroxymethyl)furfural to 2,5-Furandicarboxylic Acid with H2O2 by Unspecific Peroxygenases.

5-(Hydroxymethyl)furfural (HMF) is a key platform chemical derived from renewable biomass sources, holding great potential as starting material for the synthesis of valuable compounds, thereby replacing petrochemical-derived counterparts. Among these valorised compounds, 2,5-furandicarboxylic acid (FDCA) has emerged as a versatile building block. Here we demonstrate the biocatalytic synthesis of FDCA from HMF via a one-pot three-step oxidative cascade performed via two operative steps under mild reaction conditions employing two unspecific peroxygenases (UPOs) using hydrogen peroxide as the only oxidant. The challenge of HMF oxidation by UPOs is the chemoselectivity of the first step, as one of the two possible oxidation products is only a poor substrate for further oxidation. The unspecific peroxygenase from Marasmius oreades (MorUPO) was found to oxidize 100 mM of HMF to 5-formyl-2-furoic acid (FFCA) with 95% chemoselectivity. In the sequential one-pot cascade employing MorUPO (TON up to 13535) and the UPO from Agrocybe aegerita (AaeUPO, TON up to 7079), 100 mM of HMF were oxidized to FDCA reaching up to 99% conversion and yielding 861 mg isolated pure crystalline FDCA, presenting the first example of a gram scale biocatalytic synthesis of FDCA involving UPOs.

Tunable products of 5-hydroxymethylfurfural oxidation by Zn/Co-ZIF derived catalysts

As a bio-based platform compound, 5-hydroxymethylfurfural (HMF) can be effectively converted into other high value-added derivatives. Here we report two non-noble metal catalysts for the selective oxidation of HMF, NC and Co@NC are easily obtained by pyrolysis of ZIF-8 and ZIF-67, respectively. The NC and Co@NC catalysts oxidized HMF to FFCA (Select. 95 %) and FDCA (Select. 98 %), respectively, using O2 as oxidant. Experimental and theoretical studies show that pyridinic N and graphitic N in NC has high catalytic activity for the oxidation of carbonyl groups in HMF to FFCA, while the synergistic effect of Co-N in Co@NC can completely oxidize HMF to FDCA. DFT calculations show that, compared with NC, the Co@NC containing Co-N exhibits a lower energy barrier during the aerobic oxidation of HMF to FDCA. And Co-N leads to the conversion of electrons from N to Co and promotes the activation of O2 to form O2-, and then oxidize HMF to FDCA. Interestingly, our reaction system is universal, and could achieve almost 100 % conversion of various furfural substrates to corresponding carboxylic acid. This study may provide a new/highly efficient catalysts for biomass conversion.

Non-target analysis of crude oil photooxidation products at high latitudes and their biological effects

With new oil and gas lease sales in high-latitude regions, there exists a need to better understand the chemical fate of spilled oil and its effects on biological life. To address this need, laboratory simulations of crude oil spills under sub-Arctic conditions were conducted using artificial seawater and exposure to solar irradiation to create Hydrocarbon Oxidation Products (HOPs). HOPs characterization and their biological effects were assessed using ultra high-performance liquid chromatography (UHPLC) with high resolution mass Orbitrap spectrometry and the aryl hydrocarbon receptor (AhR) chemically activated luciferase gene expression (CALUX) assay. Non-target UHPLC-Orbitrap mass spectrometry analysis identified 251 HOPs that were in greater abundance in light-exposed samples than dark controls. Oxidized polycyclic aromatic hydrocarbons were also detected, including phenanthrene quinone, anthraquinone, hydroxyanthraquinone, and 9-fluoreneone. The composition of HOPs were consistent with photo-products of alkylated two to four ring PAHs, primarily compounds between 1 and 3 aromatic rings and 1–3 oxygens. The HOP mixture formed during photochemical weathering of Cook Inlet crude oil induced greater AhR activity than parent petroleum products solubilized in dark controls, indicating that HOPs, as a complex mixture, may contribute to petroleum toxicity more than the parent petroleum compounds. These non-targeted approaches provide the most comprehensive analysis of hydrocarbon oxidation products to date, highlighting the diversity of the complex mixture resulting from the photooxidation of crude oil and the limitations of targeted analyses for adequately monitoring HOPs in the environment. Taken together, these data identify a critical “blind spot” in environmental monitoring and spill clean-up strategies as there is a diverse pool of HOPs that may negatively impact human and ecosystem health.

Comparative study on microbiological, physicochemical and nutritional properties of whole cow milk by thermal and non-thermal processing technologies

The majority of the bioactive components in milk exhibit sensitivity to heat treatments. This research is the first systematically compare the effects of thermal (low-temperature long time pasteurization, LTLT; high-temperature short time pasteurization, HTST; ultra-high temperature, UHT; microwave-assisted heating; retort sterilization) and non-thermal (ultraviolet-C, UV-C; high hydrostatic pressure processing, HPP; filtered sterilization; high-intensity ultrasound, HIUS) treatments on the physicochemical properties and immune-active serum proteins of whole milk aliquots under the equivalent microbicidal efficacy. LTLT and HTST had little impact on whole milk. HPP at 400 MPa for 5 min was an optimal alternative to pasteurized milk in terms of equivalent microbicidal efficacy, higher nutrient retention (∼6% and 16.2% loss for IgG and lactoferrin) and fewer oxidation products (0.69 nmol/mg protein carbonyls). The serum protein denaturation of 600 MPa HPP-treated milk (79.4% and 31.36% loss for IgG and lactoferrin) was significantly higher than in pasteurized milk, but still lower than in UHT milk (97.16% and 70.85% loss for IgG and lactoferrin). Since photo-oxidation induced by high-dose irradiation was detrimental to the organoleptic properties, relying on UV-C as stand-alone replacement to pasteurization is not advisable. Combined with existing pasteurization methods, UV-C can achieve superior microbial inactivation at mild sterilization temperatures. HIUS, a promising novel tool, should be further optimized regarding the relevant standards to enable it to be used in industrial-scale processing and reproducibility. Compared with traditional thermal treatments, non-thermal strategies offer a significant reduction in the microbial load of raw milk while better preserving bioactive proteins, However, optimizing processing parameters remains essential to strike a balance between microbial inactivation and retention of active substances.

The Effect of Low Temperature Storage on the Lipid Quality of Fish, Either Alone or Combined with Alternative Preservation Technologies.

Marine foods are highly perishable products due to their high content of polyunsaturated fatty acids, which can be readily oxidized to form peroxides and secondary oxidation products, thus conferring such foods undesirable organoleptic characteristics and generating harmful compounds that are detrimental to the health of consumers. The use of preservation methods that minimize lipid oxidation is required in the fishing and aquaculture industries. Low temperature storage (chilling or freezing) is one of the most commonly used preservation methods for fish and seafood, although it has been shown that the oxidation of the lipid fraction of such products is partially but not completely inhibited at low temperatures. The extent of lipid oxidation depends on the species and the storage temperature and time, among other factors. This paper reviews the effect of low temperature storage on the lipid quality of fish, either alone or in combination with other preservation techniques. The use of antioxidant additives, high hydrostatic pressure, irradiation, ozonation, ultrasounds, pulsed electric fields, and the design of novel packaging can help preserve chilled or frozen fish products, although further research is needed to develop more efficient fish preservation processes from an economic, nutritional, sensory, and sustainable standpoint.