Citric Acid Research Articles

Stoichiometry and architecture of the human pyruvate dehydrogenase complex.

The pyruvate dehydrogenase complex (PDHc) is a key megaenzyme linking glycolysis with the citric acid cycle. In mammalian PDHc, dihydrolipoamide acetyltransferase (E2) and the dihydrolipoamide dehydrogenase-binding protein (E3BP) form a 60-subunit core that associates with the peripheral subunits pyruvate dehydrogenase (E1) and dihydrolipoamide dehydrogenase (E3). The structure and stoichiometry of the fully assembled, mammalian PDHc or its core remained elusive. Here, we demonstrate that the human PDHc core is formed by 48 E2 copies that bind 48 E1 heterotetramers and 12 E3BP copies that bind 12 E3 homodimers. Cryo-electron microscopy, together with native and cross-linking mass spectrometry, confirmed a core model in which 8 E2 homotrimers and 12 E2-E2-E3BP heterotrimers assemble into a pseudoicosahedral particle such that the 12 E3BP molecules form six E3BP-E3BP intertrimer interfaces distributed tetrahedrally within the 60-subunit core. The even distribution of E3 subunits in the peripheral shell of PDHc guarantees maximum enzymatic activity of the megaenzyme.

A broad-spectrum oxidation capability Ru-CeO2 catalyst for efficient synergistic selective oxidation of benzyl alcohol

Selective oxidation of alcohols to aldehydes by molecular oxygen is one of the most important transformations in multiphase catalysis. In this paper, a catalyst with selective oxidation ability was designed and synthesized for the selective catalytic oxidation of benzyl alcohol. N-doped carbon materials were prepared by high-temperature calcination using hydrothermal reaction products of citric acid and melamine as a carbon source, and a bimetallic catalyst supported by Ru-CeO2 was constructed using the mixture as the carrier for the selective oxidation of benzyl alcohol to benzaldehyde. The results showed that the introduction of CeO2 could effectively improve the oxidizing ability and catalytic activity of the catalyst. The Ru-Ce0.05/NC170–600 catalyst was able to convert 85.5 % benzyl alcohol into benzaldehyde at 140 °C, 6 h, and 2 MPa, and the selectivity for benzaldehyde was 100 %. It was demonstrated by DFT that it was theoretically feasible to generate benzaldehyde by extracting hydrogen atoms from benzyl alcohol molecules. Further, the selective oxidation experiments on other alcohols showed that the catalyst has high activity for the oxidation of various alcohols to generate the corresponding carbonyl products, and it is a catalyst with broad-spectrum selective oxidation ability. In this study, a green synthesis route of benzaldehyde was proposed to solve the problems in the traditional process. Meanwhile, it provides a new idea for the synthesis of carbonyl products by selective oxidation of alcohols.

Effect of EDTA and Citric Acid Additive on the Polymorph, Morphology, and Photocatalytic Activity of Iron Oxyhydroxide.

Iron oxyhydroxide [FeO(OH)] is a promising photocatalyst owing to its simple synthesis at mild temperatures and narrow band gap, which allows for the efficient harvesting of visible light. The selective production of FeO(OH) polymorphs and the modulation of their morphology by changing the iron salts, salt concentration, and additives have been widely reported. This study focuses on overcoming fast charge-carrier recombination by developing FeO(OH)-based heterostructure materials. The role of a chelating ligand (EDTA and citrate) in determining the polymorph type, morphology, and photocatalytic activity of FeO(OH) was studied. The findings revealed the additive produced of nanosized α-FeO(OH)/EDTA and layered γ-FeO(OH)/citrate with superior catalytic activities.

A greener method to recover critical metals from spent lithium-ion batteries (LIBs): Synergistic leaching without reducing agents

Efficient recycling of critical metals from spent lithium-ion batteries is vital for clean energy and sustainable industry growth. Conventional methods often fail to manage large waste volumes, leading to hazardous gas emissions and dangerous materials. This study investigates innovative methods for recovering critical metals from spent LIBs using synergistic leaching. The first step optimized thermal treatment conditions (570 °C for 2 h in air) to remove binder materials while maintaining cathode material crystallinity, confirmed by X-ray diffraction (XRD) analysis. Next, response surface methodology (RSM), I-optimal, was used to examine the synergistic effects of sulfuric acid (SA) and organic acids (Org, citric and acetic acids) and their concentrations (SA: 0.5–2 M and Org: 0.1–2 M) on metal leaching for an eco-friendlier process. Results showed that adding citric acid to SA was more effective, especially at lower concentrations, than using acetic acid. The medium was tested to evaluate the impact of reductant addition. Remarkably, it was discovered that the optimized leaching mixture (1.25 M SA and 0.55 M citric acid) efficiently extracted metals without the need for any reductant like H2O2, highlighting its potential for a simpler and more eco-friendly recycling process. Further optimization identified the ideal solid-to-liquid ratio (62.5 g/L) to minimize acid use. Finally, RSM (D-optimal) was used to investigate the effects of time and temperature on leaching, achieving remarkable recovery rates of 99% ± 0.7 for Li, 98% ± 0.0 for Co, 90% ± 6.6 for Ni, and 92% ± 0.4 for Mn under optimized conditions at 189 min and 95 °C. Chemical cost analysis revealed this method is about 25% more cost-effective than conventional methods.

Rapid Synthesis of α-Hemihydrate Phosphogypsum in MgCl2 Solution by Microwave Heating.

The preparation of α-hemihydrate phosphogypsum (α-HPG) is hindered by a lengthy reaction time due to using traditional electric heating. Microwave heating was proposed for the rapid synthesis of α-HPG in MgCl2 solution. The effects of MgCl2 concentration on the heating rate of solution and conversion rate of α-HPG were investigated; the morphology of α-HPG was regulated by citric acid, and the adsorption mechanism of citric acid on the α-HPG surface was clarified. The results show that α-HPG was successfully synthesized in a MgCl2 solution by microwave heating. Increasing the MgCl2 concentration can improve both the dielectric constant and conductivity of the solution, which is advantageous for the solution to absorb more microwave energy. Consequently, the conversion rate of phosphogypsum (PG) into α-HPG was improved at higher MgCl2 concentrations. In 2.62 mol/L MgCl2 solution, the heating time is shortened to 7 min from room temperature to 95 °C, and PG was converted to α-HPG within 60 min. The morphology of α-HPG could be controlled by chemical adsorption of citric acid onto its terminal surface. In a solution containing 2.62 mol/L MgCl2 and 1.63 × 10-2 mol/L citric acid, PG was completely transformed into α-HPG at 90 min by microwave heating, whereas the reaction time was delayed to 180 min using electric heating. Accordingly, microwave heating is a highly efficient and energy-saving method for the preparation of α-HPG.

Biofortification, metabolomic profiling and quantitative analysis of vitamin B12 enrichment in guava juice via lactic acid fermentation using Levilactobacillus brevis strain KU15152.

Chemical fortification and dose supplementation of vitamin B12 are widely implemented to combat deficiency symptoms. However, in situ, fortification of vitamin B12 in food matrixes can be a promising alternative to chemical fortification. The present study aimed to produce vitamin B12-rich, probiotic guava juice fermented with Levilactobacillus brevis strain KU15152. Pasteurized fresh guava juice was inoculated with 7.2 log CFU mL-1 L. brevis strain KU15152 and incubated for 72 h at 37 °C anaerobically. The antioxidants, total phenolic compounds, vitamin B12 production, sugars, organic acids, pH and viable count were analyzed at 24, 48 and 72 h of incubation. The fermented juice was stored at 4 °C, and the changes in its functional properties were analyzed at 7-day intervals up to 28 days of storage. During fermentation, the bacteria cell count was increased from 7.01 ± 0.06 to 9.76 ± 0.42 log CFU mL-1 after 72 h of fermentation and was decreased to 6.94 ± 0.34 CFU mL-1 during storage at 4 °C after 28 days. The pH, total soluble solids, crude fiber, citric acid and total sugars decreased, while titratable acidity, total protein, antioxidants, phenolic compounds and lactic acid contents increased during fermentation. The fermented guava juice exhibited higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS)) radical scavenging activities (85.97% and 75.97%, respectively) at 48 h of fermentation. The concentration of active vitamin B12 in the sample reached 109.5 μg L-1 at 72 h of fermentation. However, this concentration gradually decreased to 70.2 μg L-1 during the storage period. During storage for 28 days at 4 °C, both the fermented and control guava juices exhibited a decline in antioxidant and phenolic compound concentrations. Furthermore, the addition of 20% honey and guava flavor enhanced the organoleptic properties and acceptability of fermented guava juice. The value-added fermented guava juice could be a novel functional food product to combat vitamin B12 deficiency. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Electrophysiological responses to appetitive and consummatory behavior in the rostral nucleus tractus solitarius in awake, unrestrained rats

IntroductionAs the intermediate nucleus in the brainstem receiving information from the tongue and transmitting information upstream, the rostral portion of the nucleus tractus solitarius (rNTS) is most often described as a “taste relay”. Although recent evidence implicates the caudal NTS in a broad neural circuit involved in regulating ingestion, there is little information about how cells in the rNTS respond when an animal is eating solid food.MethodsSingle cells in the rNTS were recorded in awake, unrestrained rats as they explored and ate solid foods (Eating paradigm) chosen to correspond to the basic taste qualities: milk chocolate for sweet, salted peanuts for salty, Granny Smith apples for sour and broccoli for bitter. A subset of cells was also recorded as the animal licked exemplars of the five basic taste qualities: sucrose, NaCl, citric acid, quinine and MSG (Lick paradigm).ResultsMost cells were excited by exploration of a food-filled well, sometimes responding prior to contact with the food. In contrast, cells that were excited by food well exploration became significantly less active while the animal was eating the food. Most cells were broadly tuned across foods, and those cells that were recorded in both the Lick and Eating paradigms showed little correspondence in their tuning across paradigms.DiscussionThe preponderance of robust responses to the appetitive versus the consummatory phase of ingestion suggests that multimodal convergence onto cells in the rNTS may be used in decision making about ingestion.

Solid-State Fermentation of Quinoa Flour: An In-Depth Analysis of Ingredient Characteristics

Plant protein ingredients are gaining attention for human nutrition, yet they differ significantly from animal proteins in functionality and nutrition. Fungal solid-state fermentation (SSF) can modulate the composition and functionality, increasing their applicability in foods. Quinoa flour (QF) served as a substrate for Aspergillus oryzae and Rhizopus oligosporus, resulting in two fermented ingredients (QFA and QFR) with different nutritional, functional, and aroma characteristics. A higher increase in protein (+35%) and nitrogen (+24%) was observed in the QFA, while fat was predominantly increased in the QFR (+78%). Fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) decreased in the QFR but increased in the QFA due to polyol production. Metabolomic analysis revealed higher lactic acid concentrations in the QFA, and higher citric, malic, and fumaric acid contents in the QFR. The SSF reduced most antinutrients, while R. oligosporus produced saponins. Olfactometry showed the development of fruity ester compounds and a decrease in metallic and cardboard aromas. Both ingredients showed an enhanced water-holding capacity, with the QFA also demonstrating an increased oil-holding capacity. Complex formation increased the particle size, reduced the solubility, and decreased the foaming properties. Mycelium production darkened the ingredients, with the QFR having a higher differential colour index. This study highlights the potential of SSF to produce ingredients with improved nutritional, sensory, and functional properties.

Indian gooseberry (Emblica officinalis Gaertn) drink spiked with spices-Immunomodulatory properties

Indian gooseberry juice (20% (v/v) was reconstituted with 5% ginger juice (v/v) extracted from freshly harvested rhizomes, 2% each of turmeric rhizome powder and black pepper powder (w/v), followed by raising the total soluble solids to 130Brix by adding sugar syrup. Finally, 5% acid lime juice of 2.45% of titratable citric acid was added to the entire mixture in order to impart a fruity flavour to the product. The entire mixture was homogenized at 175 Bar (2500 psi) with a speed of 235 rpm and was subsequently pasteurized at 1000C for 10 minutes. LC-MS/MS analysis detected phenolic compounds (2-galloyl glucose, 2,6-galloyl glucose), capsaicinoids, curcuminoids, gingerol and shogaol. Though cyclophosphamide significantly inhibited the relative weight of thymus from 0.193 ± 0.048 in normal mice to 0.077 ± 0.034, treatment with the herbal drink significantly increased the relative weight of thymus, showing increased T cell differentiation. Mice treated with the drink showed marginal increase in the WBC count, indicating recovery of immunity. Recovery of bone marrow cellularity in mice fed with the herbal drink was directly proportional to the concentration of the drink. Increase in a-esterase activity was also directly proportional to the concentration of herbal beverage.

High acidity organic waste degradation and the potential to bioremediation of heavy metals in soil by an acid-tolerant Serratia sp.

Highly acidic citrus pomace (CP) is a byproduct of Pericarpium Citri Reticulatae production and causes significant environmental damage. In this study, a newly isolated acid-tolerant strain of Serratia sp. JS-043 was used to treat CP and evaluate the effect of reduced acid citrus pomace (RACP) in passivating heavy metals. The results showed that biological treatment could remove 97.56% of citric acid in CP, the organic matter in the soil increased by 202.60% and the catalase activity in the soil increased from 0 to 0.117Ug-1. Adding RACP into soil can increase the stabilization of Cu, Zn, As, Co, and Pb. Specifically, through the metabolism of strain JS-043, RACP was also involved in the stabilization of Zn and Pb, and Residual Fraction in the total pool of these metals increased by 10.73% and 10.54%, respectively. Finally, the genome sequence of Serratia sp. JS-043 was completed, and the genetic basis of its acid-resistant and acid-reducing characteristics was preliminarily revealed. JS-043 also contains many genes encoding proteins associated with heavy metal ion tolerance and transport. These findings suggest that JS-043 may be a high-potential strain to improve the quality of acidic organic wastes that can then be useful for soil bioremediation.

Closing the loop: Biochar-supported nickel catalyst for efficient hydrogen-rich syngas production

Thermochemical conversion of agricultural by-products into hydrogen-rich syngas is a technology that offers both economic and environmental benefits. In this work, we investigated a biochar-supported nickel-based catalyst for the catalytic pyrolysis of straw biomass to produce hydrogen-rich syngas. The by-product, straw biochar, was used as a material for synthesizing fresh catalysts, achieving a closed-loop process. We explored gas yields under various conditions. The highest yields of CO and H2, reaching 0.52 L/g and 0.48 L/g, respectively, were obtained under the conditions of a pyrolysis temperature of 900 °C, a residence time of 20 min, a calcination temperature of 400 °C, a nickel loading of 15 wt%, and a citric acid to potassium hydroxide ratio of 1:4. The catalysts were characterized using XRD, H2-TPR, SEM, and TEM. The results demonstrated that biochar provides excellent support and synergy, enabling the catalyst to function at high temperatures and offering antioxidative protection to the active metals during the thermal process. Overall, this catalytic pyrolysis process, aiming for green and efficient conversion, achieved high yields of syngas and hydrogen.

The Use of Blondo (by Product from Lauric Acid Production) for Cheese Fruiters: The Study Ratio of Milk with Blondo and Citric Acid Concentration as a Coagulant

The processing of coconut milk into lauric acid produced Blondo as by product. Blondo was rich in protein, oil (fat), carbohydrates, vitamins and minerals. In addition, the fatty acids from coconut milk blondo were short and medium chain of saturated fatty acids which were very beneficial for health. From the nutritional content and physical properties, blondo had similarities with cow's milk. Thus, blondo had the potential to be processed into cheese. This study aimed to study the effect of the ratio of cow's milk with blondo and citric acid concentration as a coagulant on the quality of cheese. This research method used factorial RAK (Randomized Block Design). There were 2 factorial, namely the proportion of milk with coconut milk cream (25:75, 50:50, 75:25, 100:0) and citric acid concentration (2% and 4%). The results showed that the proportion of milk with blondo and citric acid concentration was significantly affected in the water content and protein content. However, it did not significantly affect with fat content, pH value and organoleptic taste, aroma, texture and color. Keywords: Cow's Milk, Coconut Milk, Blondo, Cheese, Citric Acid

Comparative efficacy of citric acid/tartaric acid/malic acid additive-based polyvinyl alcohol-starch composite films

To ascertain upon the ideal configuration of physico-mechanical qualities, efficient processing techniques, and network stability of the prepared bio-composite films in real-world applications, the polymeric materials shall be subjected to a careful manipulation. Such bio-composite films have outstanding combinations of biocompatibility and toxicity-associated safety qualities. Such research interventions will be beneficial for the packaging, pharmaceutical, and biomedical industries that wish to target and adopt them for commercial applications. In this article, three alternate organic acids, i.e., citric acid (CA), tartaric acid (TA), and malic acid (MA), are blended separately into polyvinyl alcohol (PVA)-starch (St)-glycerol (Gl) composite films and for the targeted purpose of enhanced crosslinking, plasticizing, and antibacterial capability of the polymer network. The organic acid-based bio-composite polymeric films were assessed in terms of swelling index (SI), in vitro degradation, tensile strength (TS), percentage elongation (%E), antibacterial activity, and cytotoxicity attributes. Among these, the MA-based PVA composite films outperformed the CA-based PVA composite film in terms of absorbency (SI 739.29%), mechanical strength (TS 4.88 MPa), and elasticity (%E 103.68%). Furthermore, following a 24-h incubation period, the MA-based films exhibited the highest proliferative effect of 215.59% for the HEK cells. In conclusion, the MA has been inferred to be the most relevant organic acid for the desired optimality of film composition, physical and biological properties, and cost.

Refermentation with yeast and lactic acid bacteria isolates: a strategy to improve the flavor of green coffee beans.

Yeast and lactic acid bacteria (LAB) play an important part in the post-harvest fermentation of coffee. This study applied lab-scale fermentation to commercial green coffee beans using dry coffee pulp as the substrate, with the aim of modifying coffee-bean flavor. In addition to spontaneous fermentation, yeast and LAB isolated from coffee beans and dried coffee pulp were added during fermentation. Co-inoculation of yeast and LAB showed a significant effect on the chlorogenic acid content after between 24 and 72 h of fermentation. Acetic, citric, malic, lactic, and quinic acids were shown to be affected significantly (P < 0.05) by fermentation and inoculation. Gas chromatography detected that esters, alcohols, aldehydes, furans, and pyrazines were the primary compounds in the coffee beans. Certain volatile groups were present in greater concentrations and broader varieties within the inoculated beans. The highest cupping scores were given to beans that had been co-inoculated with yeast and LAB. Overall, the use of yeasts and LAB starters showed potential to create coffee beverages with desirable characteristics by standardized fermentation. © 2024 Society of Chemical Industry.

Tunable cold/warm white light emitting devices based on carbon dots with multiple emissive centers

The correlated color temperature (CCT) of lighting is closely related to human emotions. However, there is still a relative lack of white light emitting devices (W-LEDs) with tunable CCT to meet application demands in different scenarios. Here, we develop a W-LED with tunable CCT based on multiple emissive centers of carbon dots (CDots) synthesized through controlled thermal carbonization of citric acid and urea. The reaction at 160 °C for 4 h results in amorphous CDots, which exhibit excitation wavelength dependent photoluminescence (PL) containing two peaks at 446 and 520 nm. However, by increasing the reaction temperature and duration, crystalline CDots are obtained, which show broad PL peaking at 650 nm. Based on their complementary spectral ranges, a W-LED with an extremely high color rendering index of 96 is demonstrated. Moreover, a W-LED with both 365 and 405 nm electroluminescent chips is designed. The W-LED shifts from cold to warm white, when the excitation chips switch from 365 to 405 nm. This adjustable CCT can create a harmonious, enjoyable, and safe lighting environment to meet the demands of different scenes.

Synergistic effect by Sorghum bicolor L., citric acid, biochar, and vermiwash amendment for the remediation of a mine-contaminated soil.

Phytoremediation is an in situ remediation and eco-friendly technique employing accumulator plant species to remove trace elements (TEs) from contaminated sites. Moreover, it has been demonstrated that both natural and synthetic amendments can enhance trace elements (TEs) phytoremediation from polluted soils through bioenergy crops. This work assessed the synergistic impact of two tested biochar (BC) from data palm (B1) and Prosopis (B2) (1.5%/ kg), citric acid (CA, 1.5 mmol/kg) and vermiwash (VW, 20 ml/kg) to enhance the remediation of tested TEs (Mn, Zn, Cd, Pb, Ni, Cu, and Fe) from Mahad AD'Dahab mine-contaminated soil by sorghum (Sorghum bicolor L.). The BC and CA amendments alone and combined with VW significantly augmented the proliferation and survival of sorghum grown in mine-contaminated soil. Considering the individual and combined applications of VW and BC, the influence on plant growth followed this order: K < VW < B2 < B1 < B1 + VW < B2 + VW < CA < CA + VW. Applying tested BC/CA and VW significantly increased chlorophyll compared to unamended soil. The outcomes revealed a substantial elevation in TE absorption in both shoot and root (p ≤ 0.05) with all tested treatments compared to the untreated soil (K). The combined application of CA and VW resulted in the most significant TE uptake of TEs at both the root and the shoot. Furthermore, adding CA or VW as a foliar spray enhanced the bioaccumulation factor (BCF) and translocation factor (TF) of studied metals. The combined addition of CA and foliar spraying of VW was more effective than the sole addition of CA or VW. Such increase reached 20.0%, 15.6%, 19.4%, 14.3%, 14.0%, and 25.6% of TF, and 13.7%, 11.9%, 8.3%, 20.9%, 20.5%,18.7%, and 19.8% of BCE for Cd, Cu, Fe, Mn, Ni, Pb, and Zn, respectively. This study highlights the efficiency of combining CA/BC with VW as a more viable option for remediating mine-contaminated soil than individual amendments. However, future research should prioritize long-term field trials to assess the efficiency of using citric acid and vermiwash for restoring contaminated mining soils.

Innovative synthesis and comprehensive electrochemical evaluation of FeVO4 for enhanced sodium-ion battery performance

Sodium-ion batteries (SIBs) are emerging as a viable alternative to the more costly and resource-constrained lithium-ion batteries (LIBs), especially in meeting the increasing need for large-scale energy storage. A significant challenge for SIBs lies in the exploration of the advanced anode materials. FeVO4 (FVO) nanoparticles were synthesized through both wet chemical and solid-phase methods by using citric acid monohydrate and ferric nitrate nonahydrate as blowing agents. XRD and TEM characterization reveals the presence of a large (101) interlayer spacing (∼4.46 Å) that accommodates the insertion and extraction of sodium ions (Na+). As anode material for storing Na+, FVO demonstrates an impressive discharge capacity of 326.5 mAh g−1 when cycling at a rate of 0.1 A g−1 over 300 cycles. In addition, the NaFePO4||FeVO4 full cell provides a discharge specific capacity of 102.8 mAh g−1 at 0.1C (1C = 154 mAg−1). The dynamic properties of the FVO/Na battery are revealed by pseudo-capacitance analysis and GITT tests. Meanwhile, the storage mechanism of Na+ is further analyzed by XPS, TEM, in-situ XRD and density functional theory calculations. Overall, this work presents new insights into the application of FeVO4 in SIBs and also demonstrates the competitive potential of FeVO4 for energy storage.

Understand the Stabilization Engineering of Ascorbic Acid, Mapping the Scheme for Stabilization, and Advancement.

Vitamin C is extensively used in cosmetic formulation, howbeit stability is the supreme demerit that limits its use in beautifying products. Numerous techniques are being employed to inhibit the degradation of vitamin C caused by formulation components to facilitate the use in skin rejuvenating products. Diverse materials are being exercised in formulation to stabilize the ascorbic acid and ingredients selected in this formulation composition help for stabilization. The initial stable prototype is developed and further optimization is accomplished by applying the design of experiment tools. The stable pharmaceutical formulations were evaluated for the evaluation parameters and designated as two optimized formulations. The analytical method for the assay of ascorbic acid from the United States pharmacopeia and the related substance method from European pharmacopeia has been modified to be used for cream formulation. The DoE design exhibited that the stability of formulation is impacted by citric acid and tartaric acid but not by propylene glycol and glycerin. The analysis results of topical formulations for the evaluation parameter exhibited satisfactory results. The in-vitro release study method has been developed, optimized, and validated to fit the analysis. The in-vitro studies have been performed for selected compositions and both the formulation has similar kinds of release patterns. The stability study as per ICH guidelines exhibited that the product is stable for accelerated, intermediate, and room-temperature storage conditions. The optimized formulation shows constant release and permeation of ascorbic acid through the skin. The formulation with the combinations of citric acid, tartaric acid, and tocopherol is more stable and the degradation of vitamin C has been reduced significantly. The beaucoup strategies in the unique composition help to protect the degradation by inhibiting the multitudinous degradation pathways.

The mitigation of citric acid on cadmium toxicity in Iris tectorum and its effects on the composition of cell walls

Cadmium (Cd), a widely distributed and highly toxic heavy metal, poses a severe threat to soil fertility and plant growth. Citric acid (CA), a small organic acid molecule, plays a crucial role in alleviating heavy metal toxicity in plants. However, the specific mechanism underlying how CA organizes and mitigates the damage caused by heavy metals to plant cells remains unclear. Therefore, we studied the impact of exogenous CA on Cd-induced stress in Iris tectorum. The results showed that the addition of exogenous CA significantly increased the activity of antioxidant enzymes and altered the content of mineral elements including Fe, Zn, Ca, and Mn. Notably, compared to the Cd-only treatment, the proportion of Cd in the root cell walls increased by 14% in the presence of CA, and this increase was due to the ability of CA to regulate the amount of polysaccharide components in the root cell walls. CA affected the activity of pectinesterase (PME), changed the degree of pectinesterification (PMD), and enhanced the root cell walls’ ability to bind Cd, thereby reducing the Cd content in the above-ground tissues and alleviating heavy metal toxicity in plants. In summary, this study provides robust evidence that supports the use of CA to improve the efficiency of urban soil remediation.

Toward a Sustainable Approach for Durably Hydrophilic and UV Protective PET Fabric through Surface Activation and Immobilization Integrating Epigallocatechin Gallate and Citric Acid.

Enhancing the hydrophilicity and UV protective property of poly(ethylene terephthalate) (PET) fabric are two significant ways to upgrade its quality and enlarge the applicable area. Biobased finishes are greatly welcomed for the fabrication of sustainable textiles; however, their application on PET fabric is still challenging compared with the case of natural fabric. This study presents a strategy that immobilizes epigallocatechin gallate (EGCG) onto PET fabric using citric acid (CA) for durably hydrophilic and UV-proof properties with negligible color change. A controllable surface-activating method integrating alkaline and deep eutectic solvent (DES) is customized for the PET fabric to promote the reactions among PET, CA, and EGCG. The hydrophilic, antistatic, and UV protective properties of functionalized PET fabric were explored. Results show that the hydrophilicity of the PET fabric after direct EGCG treatment increases but drops sharply after first-round washing due to weak interactions. The combined alkaline/DES pretreatment increases the number of hydrophilic groups and the roughness of PET fibers. After EGCG modification, the moisture regain (MR) of PET fabric increases from 0.41 to 0.64%. The contact angle and electrostatic charge half-life (T1/2) decreases from >120 to 23°, and from >60 to 0.13 s, respectively. The MR and T1/2 are well retained after a 10-cycle washing. In addition, the UV protective factor of the PET fabric increases from 18 to 36. A very slight yellowing phenomenon occurs on the PET fabric after the treatment. In all, this research attempts to integrate a biobased finishing agent and an eco-friendly cross-linker on synthetic fiber for durable functions, which is transferrable to the sustainable fabrication of other polymeric materials such as fibers or films.