Degree Of Unsaturation Research Articles

Revealing the backbone structures of land-based fulvic acids derived from river and soil through n-butylsilane reduction.

While ultra-high-resolution mass spectrometry has enabled the identification of the molecular composition of dissolved organic matter (DOM), elucidating its molecular structure remains a challenging endeavor. Here, two fulvic acids (FAs), one from river and the other from forest soil, were subjected to reduction using an optimized n-butylsilane (n-BS) reduction method. The reduction products were purified through a combination of liquid-liquid extraction and silica gel column chromatography, resulting in the separation into saturates, aromatics, and polar products. The polar products were analyzed by high-resolution mass spectrometry (HRMS), and the saturates and aromatics were analyzed using gas chromatography-mass spectrometry (GC-MS). HRMS results showed that the number of oxygen atoms and double-bond equivalent (DBE) values of FA decreased after reduction. GC-MS results revealed that a total of 270 hydrocarbon monomers were identified from the reduction products of a single sample, with the highest carbon number of cycloalkanes reaching C33. For the first time, steranes and hopanes were detected in the reduction products, potentially serving as evidence for the existence of carboxyl-rich alicyclic molecule (CRAM) precursors. Additionally, a significant number of polycyclic aromatic hydrocarbons were identified, and the potential sources of various compounds were preliminarily inferred based on their isomers. This study extends the knowledge of the possible backbone structure of the DOM and provides a new potential tool for investigating the origin and transformation mechanisms of DOM.

Replacing soybean meal with house cricket (Acheta domesticus) meal in ruminant diet: effects on ruminal fermentation, degradation, and biohydrogenation

Abstract Insect meals could be a sustainable protein source in ruminant diets to overcome the environmental, market, and feed-food-fuel issues associated with the widespread use of soybean meal (SBM). However, research on this topic is still very scarce. This study was conducted to examine the possibility of replacing SBM with house cricket (Acheta domesticus) meal (HCM) in ruminant feeding. Four cannulated sheep were fed a total mixed ration containing either 10% SBM (Control diet) or 10% of non-defatted HCM (Insect diet) over two consecutive periods. Effects on ruminal fermentation, degradation, and biohydrogenation were evaluated. Despite some differences in rumen dry matter and N degradation kinetics, replacing dietary SBM with HCM did not affect the ruminal disappearance of dry matter, N and, neutral detergent fibre of in situ incubated feedstuffs. Nor were there differences between the meals in the in vitro intestinal digestibility of rumen non-degraded nitrogen. The replacement had no negative effects on rumen pH or ammonia concentrations, but resulted in lower total and individual (i.e. acetate, propionate, butyrate, and minor) volatile fatty acid concentrations. This adverse effect was probably due, at least in part, to the unexpectedly high content of fat in HCM and its relatively high degree of unsaturation. Inclusion of HCM in the diet facilitated modulation of the fatty acid profile of the rumen digesta without negative effects on biohydrogenation pathways (e.g. it increased trans-11 18:1 and cis-9 trans-11 CLA concentrations, with only a small variation in the trans-10:trans-11 18:1 ratio). Replacing SBM with HCM in ruminant diets could be a promising alternative to address the challenges related to SBM and to improve the lipid composition of ruminant-derived products. However, further research is still needed to investigate, for example, the most appropriate level of inclusion of HCM in the diet or the use of defatted meal.

Molecular characterization of atmospheric organic aerosols in typical megacities in China

Atmospheric aerosols in megacities impact air quality and public health. However, limited information exists on the detailed molecular composition of organic aerosols in urban areas. This study characterized the molecular composition of organic aerosols (OA) in Shanghai, Beijing and Guangzhou, China, during summer and winter of 2021. Liquid chromatography-orbitrap mass spectrometry detected 4536−5560 and 2067− 3489 organic molecular formulas in positive (ESI+) and negative (ESI−) electrospray ionization modes, respectively. CHO and CHON compounds accounted for over 80% and 60% of total abundance in ESI+ and ESI−, respectively, suggesting their significant contribution to urban OA. The number and abundance percentages of CHO showed obvious seasonal variation, with more CHO in summer than in winter, while CHON exhibited the opposite trend in Beijing and Shanghai. Compared with winter, a lower unsaturation degree, reduced aromaticity, and higher oxidation state of OA in summer were observed in Beijing and Shanghai, while these seasonal variations were not as obvious in Guangzhou, likely due to regional climate differences. The number percentage of common compounds between Beijing and Shanghai was higher than that between Guangzhou and Beijing (or Shanghai). Nitroaromatic compounds were more prevalent in winter than in summer. Further analysis of atmospheric formation relevance and precursor-product pairs suggested that CHON compounds are derived from the oxidization or hydrolyzation processes, revealing potential chemical transformations of these aerosols. This study characterized the chemical makeup of organic aerosols, providing insight into their sources and characteristics in these cities.

Comparison of environmental impacts from pyrolysis, gasification, and combustion of oily sludge

Thermochemical treatment of oily sludge (OS) has been demonstrated to be an effective approach for resource and energy recovery. However, the migration and emission of potential pollutants have limited its further development. In this study, the environmental impacts, including aromatic compounds in liquid products, N-, S-, and Cl-containing pollutants in gaseous products, and residual organic matter and heavy metals in solid residues, during the pyrolysis, gasification, and combustion processes of OS are comparatively investigated. The results indicate that the aromatics in the liquid products obtained from pyrolysis and gasification are primarily hydrocarbons with 10, 14, and 16 carbon atoms, and the corresponding degree of unsaturation is between 7 and 16. By contrast, the aromatics produced during combustion are mainly hydrocarbons with 10–12 carbon atoms and an unsaturation degree of 7. The liquid products from gasification of OS contain aromatics with more carbon atoms and a higher degree of unsaturation, suggesting potential issues of recalcitrant aromatics and tar by-products during the gasification process. The release behaviors of N-, S-, and Cl-containing pollutants during the thermochemical treatment of OS are closely related to the specific thermochemical technology and treatment temperature. At 550 °C, these pollutants are gradually released from the OS. By contrast, at 950 °C, they are released over a narrow temperature range with significantly higher concentrations. Furthermore, compared with the peak concentrations of SO2 and HCl during thermochemical processing at 550 °C, these values increase by 1–2 orders of magnitude at 950 °C. With the increase in treatment temperature, the loss on ignition (LOI) of residues from pyrolysis or gasification of OS gradually decreases and stabilizes around 0.5 %. On the other hand, the LOI from combustion fluctuates around 1.0 %. In addition, the removal rates of total organic carbon in the residues from all three thermochemical processes exceed 98.89 %. However, the potential ecological risks associated with heavy metals in the residues from thermochemical treatment of OS also increase to some extent. Cr, Cu, and Zn are found to evaporate and escape into liquid and gaseous products, while Pb is retained in the residues. Notably, the residue from combustion poses the highest environmental risks among the three processes.

Assessment of the Migration of Polar Compounds from Petroleum-Contaminated Soil Using a Column Leaching Experiment.

When petroleum leaks into soil, the polar compounds exhibit strong biological toxicity, causing serious damage to soil animals, plants, and microorganisms and potentially threatening human health. However, the systematic comprehension of the migration of polar compounds in petroleum-contaminated soil remains limited. Herein, we employed elemental analysis, stable carbon isotope analysis, and high-resolution mass spectrometry techniques to study the migration of polar compounds in petroleum-contaminated soil using a column leaching experiment. The results indicate that petroleum migration ability in soil is limited, and the compounds are primarily concentrated in the soil above 40 cm. The C/N, C/H, and δ13C ratios of organic matter in soils are highly affected by petroleum contamination. Meanwhile, the different compound classes show varying migration abilities, with N1 and N1O1 compounds exhibiting stronger adsorption capacity on soil, while oxygen-containing compounds are more likely to migrate with water to deeper soil. Additionally, molecular polarity, unsaturation degree, and size are key factors affecting the migration of polar compounds in petroleum within the soil. This simulation experiment offers valuable insights into comprehending migration of polar compounds in petroleum-contaminated soil and their potential impacts for soil ecological environment.

Microencapsulation and characterization of pomegranate seed oil using gum Arabic and maltodextrin blends for functional food applications

AbstractPomegranate seed oil (PSO) is highly valued in the functional food industry due to its rich fatty acid content and associated health benefits. However, its high degree of unsaturation makes it susceptible to rapid degradation when exposed to oxygen and light. This study investigates the encapsulation of PSO at 15% w/w using different blends of gum Arabic (GA) and maltodextrin (MD) (1:0, 0:1, 1:1, 3:1, and 1:3) to determine optimal formulations for enhanced stability and functional quality. Characterization of the encapsulated PSO powders showed distinct particle morphologies, including flake‐like shapes and textures ranging from smooth to wrinkled and porous. The Fourier transform infrared (FT‐IR) spectra indicated shifts in functional groups from 2973.70 to 408.84 cm−1, revealing the presence of aliphatic, amine, aromatic, carboxylic acid, and hydroxyl groups. Although no single formulation achieved all desired outcomes, the GA:MD ratios of 1:0 and 1:1 were superior in enhancing color properties (yellowness and chroma), techno‐functional attributes (bulk density and solubility), and in preserving essential fatty acids, including stearic, cis‐oleic, α‐linolenic, arachidic, γ‐linolenic, linoleic, and punicic acids. Additionally, GA:MD (3:1) powders exhibited superior ferric‐reducing antioxidant power (FRAP) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activities (RSA). In conclusion, formulations using solely GA or GA:MD ratios of 1:1 and 3:1 effectively preserve bioactive content in PSO, enhancing its antioxidant capacity. These findings suggest promising applications for these encapsulated powders in developing functional foods that meet industry demands.

Elucidating maternal provisioning for bivalve larvae under ocean acidity extreme events

Ocean acidity extreme (OAX) events, triggered by climate change and anthropogenic activities, are projected to become more intense and frequent in coastal ecosystems, devastating marine bivalves and ecosystems they support. Maternal effects adaptively modulate offspring performance in response to climatic stressors, but whether and to what extent they can confer offspring resistance to OAX remain largely unknown. Here, we investigated impacts of OAX on the parental and larval lipidomes of Manila clams (Ruditapes philippinarum) to add further insights into the energetic nature of maternal effects. A total of 177 significantly down-regulated lipid components (categorized into glycerolipids mainly) were shown in OAX-stressed adults compared with those reared under ambient conditions, and following parental conditioning, larvae also exhibited a further decreasing down-regulation of the glycerolipid components. Triacylglycerols were identified as the predominant composition of glycerolipids and the primary sources of energy for gonadal maturation and larvae development. Yet, larvae spawn from adults exposed to OAX had significantly lower contents of triacylglycerols than those without a prior history of parental conditioning, with the carbon chain length and unsaturation degree of the triacylglycerol components being significantly affected. The latter was also in line with significant increases in the production of triacylglycerol byproducts (diacylglycerols). Overall, our findings suggest that when OAX prevailed during reproductive seasons of Manila clams, maternal effects could be maladaptive by depressing the energetic deposition of larvae, and may not be a potential adaptive modulator of marine bivalves to cope with unprecedented environmental change.

Investigating the Influence of the Substrate Temperature and the Organic Precursor on the Mechanical Properties of Low‐Pressure Plasma Polymer Films

ABSTRACTThis work aims to investigate the influence of the substrate temperature on low‐pressure plasma polymerization processes. Emphasis is placed on the mechanical properties and growth mechanism of the plasma polymer films (PPFs). For this purpose, two precursors are considered, differing only by their unsaturation degree: 2‐propen‐1‐ol (CH2═CH–CH2–OH) and propan‐1‐ol (CH3–CH2–CH2–OH). Although propan‐1‐ol‐based PPFs behave like hard elastic solids, 2‐propen‐1‐ol‐based coatings evolve from a liquid film to an elastic solid on increasing the substrate temperature. This behavior is understood considering the evolution of the glass transition temperature of PPFs. The latter is correlated with the cross‐linking degree of the polymeric network governed by the energy density of bombarding ions on the growing film.

Effects of ultra-high pressure processing on microstructure, water distribution and lipidomics variances of Arabica coffee beans

The emerging non-thermal technique of ultra-high pressure (UHP) processing technology has seen significant advancements in food processing in recent years. The present study aimed to analyze the impact of UHP (100–300 MPa) processing on the color, microstructure, water distribution, and lipidomics variations of wet-processed Arabica coffee beans. The results indicated that the brightness and chromatic aberration of coffee beans were significantly altered by UHP processing, while other color parameters remained relatively unaffected. Scanning electron microscope examinations showed that UHP processing caused compression, compaction, and even collapse of the pore structure within coffee beans. Compared to wet-processed Arabica coffee beans, UHP processing promoted a more even water distribution and facilitated the conversion of bound and immobilized water into free water, with the maximum effect observed during UHP-200 treatment. Lipidomics analysis indicated that triacylglycerol (TAG, 24.75 %) and diacylglyceryl trimethylhomoserine (DGTS, 11.23 %). Notably, UHP-100, UHP-200, and UHP-300 samples exhibited 238, 191, and 788 differentially expressed lipids. The carbon chain length and degree of unsaturation of all differentially expressed lipids exhibited a pressure-dependent decrease with intricate interrelationships.

Plastic film from the source of anaerobic digestion: Surface degradation, biofilm and UV response characteristics

This study simulates a major environmental scenario involving “organic fertilizer source” plastics, by exploring the key factors influencing the changes in plastic-films during anaerobic digestion (AD), as well as the responses of the anaerobically digested plastics to ultraviolet (UV) radiation exposure. The results demonstrate that the degradation effect of AD on plastics is reflected by their yellowish and ruptured appearance, slightly worn surfaces, hardening and opacity, and fragmentation. AD significantly increases the content of oxygen-containing functional groups and the degree of unsaturation in plastic films, with thermophilic temperature processes proving more effective than those conducted at mesophilic temperatures. Exposure to UV light has been found to amplify the degradative effects, suggesting the potential cumulative impact of AD and UV. Both AD and UV irradiation reduced the hydrophilicity of plastics. In particular, the hydrophobicity of polylactic acid films was completely disrupted under overlay-exposure. Furthermore, microbial populations on plastic surfaces were mainly bacterial. These bacterial populations were primarily influenced by temperature, and moderately by the plastic types. In contrast, archaea were predominantly affected by both temperature and digested substrate. This study offers a theoretical foundation for strategies aimed at preventing and controlling plastic pollution derived from organic fertilizers.

Evaluation of seed oil from Hura crepitans, Trichosanthes cucumerina and Thevetia nerifolia

The oil contents and fatty acid composition of three non-edible seed oils extracted using Soxhlet extraction with hexane as the solvent were presented. The physical and chemical properties of the oils were determined from which cetane number, biofuel potential, higher heating values, and antimicrobial activities were assessed. The dominant fatty acids were 49 % linoleic acid, 37 % pentadecenoic acid, and 38 % cis-10-heptadecenenoic acid for Hura crepitans (HC), Thevetia nerifolia (TN) and Trichosanthes cucumerina (TC), respectively. The seed oils were majorly unsaturated, with HC having the highest degree of unsaturation. Acid value, saponification value, iodine value, and free fatty acids were low compared to many reported values in literature. The cetane values were generally high because the oils have a reasonable amount of saturated fatty acid, with TN having the highest cetane number. The low iodine value and saponification value make the biofuel potential and higher heating value to be high with TN having the highest in both and thus the best seed oil for biofuel. However, TN and HC have no antimicrobial activity to Klebsiella pneumoniae (gram -ve), Staphylococcus aureus (gram +ve), Escherichia coli (gram -ve), Bacillus subtilis, Enterobacter aerogenes, Candida albican, Rhizopus stolonifer, Fusarium Solani, Aspergillus flavus and Candida tropicalis, while TC has broad spectrum of activity against all tested bacteria and fungi, except Klebsiella pneumoniae.

Fine mapping-based multi-omics analysis interprets the gut-lung axis function of SGLT2 inhibitors.

Currently, Sodium-glucose cotransporter 2 (SGLT2) inhibitors demonstrate additional effects beyond glucose control on the gut microbiota and circulating metabolites. The gut microbiota and metabolites have been found to be useful in elucidating potential biological mechanisms of pulmonary diseases. Therefore, our study aims to investigate the effects of gut microbiota and metabolites mediating SGLT2 inhibition in 10 pulmonary diseases through Mendelian randomization (MR) research. We conducted a two-sample, two-step MR study to assess the association between SGLT2 inhibition and 10 pulmonary diseases and to investigate the mediating effects of gut microbiota and metabolite. Gene-fine mapping and annotation of mediators by FUMA and Magma analyses were performed, and causal associations of mapped genes with diseases were assessed by muti-omics MR analyses. Possible side effects of SGLT2 inhibition were assessed by PheWAS analysis. SGLT2 inhibition was linked to a reduced risk of T2DM, Interstitial lung disease (ILD), Pneumoconiosis, Pulmonary tuberculosis, and Asthma(OR=0.457, 0.054, 0.002, 0.280, 0.706). The family Enterobacteriaceae and order Enterobacteriales were associated with SGLT2 inhibition and ILD(95% CI:0.079-0.138). The family Alcaligenaceae and X-12719 were linked to pneumoconiosis (95% CI: 0.042-0.120, 0.050-0.099). The genus Phascolarctobacterium was connected to pulmonary tuberculosis (95% CI: 0.236-0.703).The degree of unsaturation (Fatty Acids), ratio of docosahexaenoic acid to total fatty acids, and 4-androsten-3beta,17beta-diol disulfate 2, were associated with asthma(95% CI: 0.042-0.119, 0.039-0.101, 0.181-0.473). Furthermore, Fuma and Magma analyses identified target genes for the four diseases, and proteomic MR analysis revealed six overlapping target genes in asthma. PheWAS analysis also highlighted potential side effects of SGLT2 inhibition. This comprehensive study strongly supports a multi-omics association between SGLT2 inhibition and reduced risk of interstitial lung disease, tuberculosis, pneumoconiosis, and asthma. Four identified gut microbiota, four metabolites, sixteen metabolic pathways, and six target genes appear to play a potential role in this association. The results of the comprehensive phenome-wide association analysis also identified the full effect of SGLT2 inhibitors.

Separation of triacylglycerol (TAG) isomers by cyclic ion mobility mass spectrometry

Triacylglycerols (TAGs), a major lipid class in foods and the human body, consist of three fatty acids esterified to a glycerol backbone. They can occur in various isomeric forms, including sn-positional, cis/trans configurational, acyl chain length, double bond positional, and mixed type isomers. Separating isomeric mixtures is of great interest as different isomers can have distinct influence on mechanisms, such as digestibility, oxidative stability, or lipid metabolism. However, TAG isomer separation remains challenging with established analytical methodologies such as liquid-chromatography coupled to mass spectrometry (LC-MS). In this study, we developed a method with cyclic ion mobility mass spectrometry (cIMS-MS) for the separation and identification of all types of TAG isomers. First, the influence of different adducts (Li+, NH4+, Na+, and K+) on the separation was studied. Overall, it was concluded that the sodium adduct is the best choice to efficiently separate all types of TAG isomers. In addition, trends were found in the influence of specific structural features on the drift time order. An order of relative influence (from high to low) was established; (1) degree of unsaturation of the fatty acid(s) on an exterior position (if the total degree of unsaturation(s) is equal in both TAGs), (2) acyl chain length on the exterior positions, (3) cis/trans configuration, and (4) double bond (DB)-position. Finally, various cIMS-MS strategies were developed for the separation of mixtures containing four, five, and six isomers. To conclude, the developed methods can be used for separation of complex mixtures of TAG isomers and have great potential to be expanded to isomers of similar types of lipids such as di- and monoacylglycerols. This study also shows the potential of cIMS-MS to be used for the application on real TAG samples.

Nanoscale Structural Characterization of Amyloid β 1-42 Oligomers and Fibrils Grown in the Presence of Fatty Acids.

Mono- and polyunsaturated fatty acids (FAs) are broadly used as food supplements. However, their effect on the aggregation of amyloidogenic proteins remains unclear. In this study, we investigated the effect of a large number of mono- and polyunsaturated, as well as fully saturated FAs on the aggregation of amyloid β1-42 (Aβ1-42) peptide. A progressive aggregation of this peptide is the expected molecular cause of Alzheimer's disease (AD), one of the most common neurodegenerative pathologies in the world. We found that arachidonic and stearic acids delayed the aggregation of Aβ1-42. Using Nano-Infrared spectroscopy, we found that FAs caused very little if any changes in the secondary structure of Aβ1-42 oligomers and fibrils formed at different stages of protein aggregation. However, the analyzed mono- and polyunsaturated, as well as fully saturated FAs uniquely altered the toxicity of Aβ1-42 fibrils. We found a direct relationship between the degree of FAs unsaturation and toxicity of Aβ1-42 fibrils formed in their presence. Specifically, with an increase in the degree of unsaturation, the toxicity Aβ1-42/FA fibrils increased. These results indicate that fully saturated or monounsaturated FAs could be used to decrease the toxicity of amyloid aggregates and, consequently, decelerate the development of AD.

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.

Experimental and numerical study of laminar burning velocity for Diisobutylene+ PRF/TRF mixtures

DIB (Diisobutylene, JC8H16) strongly correlates with real gasoline and significantly impacts the combustion behavior of alternative fuels designed as gasoline substitutes. However, accuracy concerns persist in laminar burning velocity data reported in literature. In this paper, the laminar burning velocities of DIB + air, DIB + PRF + air, and DIB + TRF + air mixtures were measured by the heat flux method at 1 atm. (PRF, Primary Reference Fuel; TRF, Toluene Reference Fuel) The equivalence ratio was controlled within 0.6–1.3, and the initial temperatures were set at 298K, 318K, and 338K. Additionally, by employing the mechanism proposed by Ren et al., the simulated values align with the experimental data, thus prompting the conduction of a reaction kinetic analysis. The analysis of chemical reaction kinetics reveals the reaction pathways of DIB, with a notable observation that an increase in temperature or a decrease in equivalence ratio can both lead to an elevation in the degree of unsaturation in the bonds of intermediate species. During laminar flame combustion, PRF and TRF compete with DIB for oxygen, with PRF appearing to have a stronger ability to capture oxygen. In addition, the laminar burning velocity temperature dependence coefficient α decreases first and then increases with the increase of the equivalence ratio, where the minimum α is obtained at equivalence ratio = 1.1. Additionally, the laminar burning velocity at higher initial temperatures is estimated by the extrapolation method and compared with the experimental data reported in literature.

Unveiling the oxidative stability, phytochemical richness, and nutritional integrity of cold-pressed Linum usitatissimum oil under UV exposure

This study examines the effect of UV irradiation on the oxidation stability of Linum usitatissimum oil, presenting possible changes in the phytochemical profile due to photo-oxidation. GC–MS analysis of the oils identified 11 fatty acid compounds with a high percentage of unsaturated fatty acids, the most important of which is α-linolenic acid (ALA), known as omega-3 (48.88 %), also significant profiles of phytosterol and tcocopherol isomers rich in β-Sitosterol and γ-tocopherols respectively. As well as physicochemical properties such as free fatty acids (FFA %), peroxide value (PV) and iodine value (IV), and nutritional indexes that determine the significant changes observed during the oxidation process, the most important of which is the progressive increase in acidity, peroxide, conjugated dienes and trienes and degrees of unsaturation over 8 h of UV exposure. High levels of carotenoids and phenolic compounds (TPC) protect and enhance oil quality in the face of irradiation, so a significantly small difference is observed between irradiated and non-irradiated oil during photo-oxidation.

Evaluation of antioxidant potential of anthocyanin-rich hydro ethanol extract of Syzygium cumini fruit pulp in various in vitro models and in food supplement enriched with omega-3 fatty acids

Omega-3 fatty acids have immense health benefits but are highly susceptible to oxidation due to high degree of unsaturation in their molecular structure. Therefore, development of omega-3 fatty acids fortified stable functional food is a challenging task. The aim of the study was to evaluate antioxidant potential of anthocyanin-rich hydro ethanol extract of Syzygium cumini fruit pulp extract in various in vitro models and in omega-3 fatty acids enriched food supplement in bulk oil and oil-in-water emulsions model systems along with chemical analysis of the fruit pulp extract and evaluation of its cytotoxic potential, if any. The in vitro antioxidant potential was evaluated by DPPH radical scavenging, ABTS°+ decolorization and Fe2+ ion chelating methods. Antioxidant activity against oxidation of omega-3 fatty acids enriched food supplement in bulk oil and oil-in-water emulsions model systems was evaluated by monitoring primary oxidation, secondary oxidation and total oxidation of the omega-3 enriched oil using AOCS guidelines and iodometric method. Chemical analysis was performed by HR-LCMS analysis technique. Cytotoxic potential was evaluated by Allium cepa test. The test extract exhibited varying degrees of antioxidant activity in various in vitro models as well as against oxidation of omega-3 fatty acids enriched food supplement both in bulk oil and oil-in-water emulsions model systems. Chemical analysis revealed the presence of three major tentatively identified compounds malvidin-3,5-diglucoside, delphinidin-3,5-diglucoside and peonidin-3,5-diglucoside as major components of the extract. Test extract did not show any cytotoxic potential at recommended dosage level with LC50> 1000 µg/ml. The results provide evidence that anthocyanin-rich hydro ethanol extract of Syzygium cumini fruit pulp may serve as a potential source of safe and effective, novel natural antioxidant for retarding oxidation of omega-3 fatty acids enriched food supplement which subsequently may help to develop omega-3 fortified stable functional foods in food industry.

The Lubricity of Gases

A sealed reciprocating tribometer has been used to study the influence of different gaseous environments on the friction and wear properties of AISI52100 bearing steel at atmospheric pressure and 25 °C. Helium, argon, hydrogen, carbon dioxide and nitrogen all give high friction and wear, suggestive of very little, if any tribofilm formation under the conditions studied. Dry air and oxygen also give high friction, slightly lower than the inert gases, but produce extremely high wear, much higher than the inert gases. This is characteristic of the phenomenon of “oxidational wear”. The two gases ammonia and carbon monoxide give relatively low friction and wear, and XPS analysis indicates that this is due to the formation of adsorbed ammonia/nitride and carbonate films respectively. For the hydrocarbon gases studied, two factors appear to control friction and wear, degree of unsaturation and molecular weight. For the saturated hydrocarbons, methane and ethane give high friction and wear but propane and butane give low friction after a period of rubbing that decreases with molecular weight. The unsaturated hydrocarbons all give an immediate reduction in friction with correspondingly low wear. Raman analysis shows that all the hydrocarbons that reduce friction and wear form a carbonaceous tribofilm on the rubbed surfaces.Graphical

Influence of phospholipid head and tail molecular structures on cell membrane mechanical response under tension.

Biological cell membranes are primarily comprised of a diverse lipid bilayer with multiple phospholipid (lipid) types, each of which is comprised of a hydrophilic headgroup and two hydrophobic hydrocarbon tails. The lipid type determines the molecular structure of head and tail groups, which can affect membrane mechanics at nanoscale and subsequently cell viability under mechanical loading. Hence, using molecular dynamics simulations, the current study investigated seven membrane phospholipids and the effect of their structural differences on physical deformation, mechanoporation damage, and mechanical failure of the membranes under tension. The inspected phospholipids showed similar yield stresses and strains, as well as pore evolution and damage, but significantly different failure strains. In general, failure occurred at a lower strain for lipids with a larger equilibrium area per lipid. The obtained results suggest that larger headgroup structure, greater degree of unsaturation, and tail-length asymmetry influenced the phospholipids' ability to pack against each other, increased the fluidity and equilibrium area per lipid of the membrane, and resulted in lower failure strain. Overall, this study provides insights on how different phospholipid structures affect membrane physical responses at the molecular level and serves as a reference for future studies of more complex membrane systems with intricate biophysical properties.