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ACS Omega Apr 2024Developing an environmentally friendly soy protein-based film that offers excellent performance has garnered considerable interest while also posing a significant...
Developing an environmentally friendly soy protein-based film that offers excellent performance has garnered considerable interest while also posing a significant challenge. Herein, we propose the strategy of covalent and noncovalent cross-linking to improve the mechanical properties of the films. First, chemical denaturation was carried out under the combined action of sodium sulfite, sodium dodecyl sulfate, sodium hydroxide, and urea to reshape the structure of the protein to improve the solubility of protein and release active groups. Then, microcrystalline cellulose (MCC) derived from low-cost agro-industrial byproducts (corn husk) was employed to balance the covalent cross-linking reaction between proteins and the noncovalent reaction between MCC and protein. The results indicate that the structure and properties of the soy protein-based films were modified and improved through chemical treatment in conjunction with biomass enhancement. It is concluded that the addition of 1% MCC improves the tensile strength, elastic modulus, water solubility, and water vapor permeability of "MCC-1%" by 64.7, 75.9, 22.7, and 12.9%, respectively. Additionally, the resulting film of "MCC-1%" exhibits better resistance to thermal degradation and improved thermo-stability. However, the elongation at break decreased by increasing the addition of MCC. Thus, this work may provide a simple and affordable approach to preparing a high-performing soy protein-based film.
PubMed: 38617662
DOI: 10.1021/acsomega.3c07907 -
Biomedical and Environmental Sciences :... Feb 2024As a reducing salt, sodium sulfite could deprive oxygen in solution, which could mimic hypoxic stress in . In this study, the wild-type strain MG1655 was used to...
As a reducing salt, sodium sulfite could deprive oxygen in solution, which could mimic hypoxic stress in . In this study, the wild-type strain MG1655 was used to examine the inhibition of sodium sulfite-induced hypoxia by observing the bacterial growth curves. We also analyzed the growth curves of mutant strains (for , , , and ) related to hypoxic pathways to reveal roles of the related genes during hypoxia. The ultrastructure of hypoxia-inhibited bacteria were also observed using transmission electron microscopy. Sodium sulfite could maintain hypoxic condition of bacterial culture for 8 h with concentrations over 40 mmol/L. Complete ultrastructure of the bacteria indicated sodium sulfite did inhibit bacterial growth and division. Among the hypoxia genes, and played key roles in sodium sulfite-induced hypoxia. This study showed that sodium sulfite could be used as a novel hypoxia revulsant for bacterial cultures.
Topics: Humans; Escherichia coli; Escherichia coli Proteins; Repressor Proteins; Bacterial Outer Membrane Proteins; Hypoxia; Gene Expression Regulation, Bacterial; Sulfites
PubMed: 38582987
DOI: 10.3967/bes2024.025 -
Molecules (Basel, Switzerland) Mar 2024Currently, little is known about the characteristics of polyphenol oxidase from wheat bran, which is closely linked to the browning of wheat product. The wheat PPO was...
Currently, little is known about the characteristics of polyphenol oxidase from wheat bran, which is closely linked to the browning of wheat product. The wheat PPO was purified by ammonium sulfate precipitation, DEAE-Sepharose ion-exchange column, and Superdex G-75 chromatography column. Purified wheat PPO activity was 11.05-fold higher, its specific activity was 1365.12 U/mg, and its yield was 8.46%. SDS-PAGE showed that the molecular weight of wheat PPO was approximately 21 kDa. Its optimal pH and temperature were 6.5 and 35 °C for catechol as substrate, respectively. Twelve phenolic substrates from wheat and green tea were used for analyzing the substrate specificity. Wheat PPO showed the highest affinity to catechol due to its maximum V (517.55 U·mL·min) and low K (6.36 mM) values. Docking analysis revealed strong affinities between catechol, gallic acid, EGCG, and EC with binding energies of -5.28 kcal/mol, -4.65 kcal/mol, -4.21 kcal/mol, and -5.62 kcal/mol, respectively, for PPO. Sodium sulfite, ascorbic acid, and sodium bisulfite dramatically inhibited wheat PPO activity. Cu and Ca at 10 mM were considered potent activators and inhibitors for wheat PPO, respectively. This report provides a theoretical basis for controlling the enzymatic browning of wheat products fortified with green tea.
Topics: Catechol Oxidase; Dietary Fiber; Hydrogen-Ion Concentration; Kinetics; Plant Proteins; Catechols; Substrate Specificity; Tea
PubMed: 38542970
DOI: 10.3390/molecules29061334 -
Bio Systems Apr 2024A frequently debated topic related to the origin of life centers around the question of how complex forms of life on today's Earth may have evolved over time from...
A frequently debated topic related to the origin of life centers around the question of how complex forms of life on today's Earth may have evolved over time from simpler predecessors. For example, the question of how proton concentration gradients across cellular membranes developed in ancestral protocells remains unanswered. This process, which is indispensable for the generation of chemical energy in modern organisms, is driven by energy derived from redox processes in the respiratory chain. Since it is highly unlikely that the complex machinery of the respiratory chain was available on early Earth, we provide an example of how proton gradients can be established in less complex systems. Utilizing liposomes as models of primitive cells, we were able to generate proton gradients of about two pH units across the liposome bilayers using redox reactions as the driving force. Electrons were transferred from sodium sulfite present on the outside of the liposomes to ferricyanide, which was trapped on the inside. A lipid-soluble phenazine derivative served as a shuttle that transferred both electrons and protons across the lipid bilayer. Because sulfite would have been an abundant reduced solute available to the earliest cells, we propose that it may have been a primary source of redox energy for primitive chemiosmotic energy transduction.
Topics: Protons; Liposomes; Lipid Bilayers; Oxidation-Reduction; Sulfites
PubMed: 38479655
DOI: 10.1016/j.biosystems.2024.105189 -
Journal of Dairy Science Jun 2024Condensed tannins (CT) are plant polyphenols that can affect feed digestibility and are potentially able to reduce enteric CH emissions in ruminants. In this in vivo...
Condensed tannins (CT) are plant polyphenols that can affect feed digestibility and are potentially able to reduce enteric CH emissions in ruminants. In this in vivo trial with 8 lactating goats, we investigated the effects of 4 levels of inclusion of a commercial CT extract from quebracho (0%, 2%, 4%, and 6% on dry matter basis; CON, Q2, Q4, and Q6, respectively). The experimental design was a repeated 4 × 4 Latin square with 28-d periods (24 d of diet adaptation and 4 d of sample collection) using metabolic cages and 4 open-circuit respiration chambers. The inclusion of CT in the diets did not affect the dry matter intake (DMI) but caused a linear decrease in diet digestibility, with reductions up to -11% for dry matter, -21% for crude protein (CP), -23% for α-amylase- and sodium sulfite-treated neutral detergent fiber corrected for insoluble ash (aNDFom), and -13% for gross energy, when comparing the Q6 and CON diets. However, ruminal total volatile fatty acids (VFA) concentration was not affected by CT, although there were changes in VFA proportions. Milk yield was highest for Q4 (3,371 g/d) and lowest for Q6 (3,066 g/d). In terms of milk composition, CT induced a linear reduction of fat and CP concentrations. The reduction in CP digestibility resulted in a linear reduction in the milk urea level, up to -37% with Q6. Positively, CT linearly reduced the somatic cells count expressed as linear score. The feed efficiency was linearly decreased by CT inclusion. Furthermore, a shift from urinary to fecal nitrogen excretion was observed with CT. The retained nitrogen was always negative (on average -1.93 g/d). The CH yield (on average 19.2 g of CH/kg DMI) was linearly reduced by CT inclusion, up to -18% with Q6. Regarding the CH intensity, CT induced a linear reduction when expressed per kilogram of milk, but not per kilogram of fat and protein-corrected milk. Moreover, the CH production per kilogram of digestible aNDFom was linearly increased by CT. The metabolizable energy intake (MEI) was not affected by the treatments, but the metabolizability (q = MEI/gross energy intake) was reduced as CT inclusion increased. From the results of the present study, it turned out that CT have a negative impact on feed digestibility and feed use efficiency. Condensed tannins can lower CH emissions from ruminants; however, the main mechanism of action is likely the decrease in feed digestibility. Furthermore, CT did not improve the N use efficiency. According to these findings, the positive environmental impacts of CT are only related to the shift from urinary to fecal N excretion.
Topics: Animals; Goats; Female; Lactation; Milk; Diet; Digestion; Methane; Nitrogen; Animal Feed; Proanthocyanidins; Energy Metabolism
PubMed: 38246549
DOI: 10.3168/jds.2023-24076 -
Se Pu = Chinese Journal of... Dec 2023The complex matrix of soil samples and low extraction efficiency of aniline compounds limit many methods developed for detecting aniline and benzidine compounds in soil....
The complex matrix of soil samples and low extraction efficiency of aniline compounds limit many methods developed for detecting aniline and benzidine compounds in soil. In this study, a rapid and sensitive method based on gas chromatography-mass spectrometry was developed for the simultaneous determination of 14 aniline and benzidine compounds in soil. The collected soil samples were sealed with 5% sodium sulfite solution and refrigerated to inhibit the oxidation of the target compounds for up to 7 d. The extraction efficiencies of accelerated solvent extraction and oscillating dispersion extraction were compared, and the recovery of accelerated solvent extraction was found to be unsuitable. Hence, three-phase oscillating dispersion extraction was adopted. A certain amount of alkaline aqueous solution was added to the test system during extraction to improve the extraction efficiency because aniline and benzidine compounds are weakly alkaline substances. When the pH of the extracted water phase was greater than 12, relatively good recoveries were obtained. Next, a mixed solvent of ethyl acetate-methylene chloride (1∶4, v/v) was added to extract the target compounds via oscillation for 20 min. The solid phase was discarded via centrifugation, and the aqueous and organic phases were transferred to a liquid separation funnel for further separation. Finally, the organic phase was retained. This pretreatment process prevents the co-extraction of acidic compounds or other impurities, thereby enhancing the purification ability of the method. Solid phase extraction (SPE) is generally recommended for soil extraction and purification. A preliminary test showed that compared with other columns, the Florisil SPE column could better retain the target substances and exhibited higher elution efficiency. After purification, the organic phase was concentrated to 1 mL using a nitrogen blower. The analytes were analyzed by gas chromatography-mass spectrometry using a capillary column (DB-35MS, 30 m×0.25 mm×0.25 μm). The temperature program was optimized to separate the target compounds at the baseline. Specifically, the initial oven temperature was set to 60 ℃, held for 2 min, increased to 130 ℃ at a rate of 5 ℃/min, increased to 300 ℃ at a rate of 30 ℃/min, and held for 4 min. The injector and ion source temperatures were 250 and 300 ℃, respectively. Aniline-d and acenaphthene-d were used as the internal standards for quantification. The effects of antioxidant addition, extraction solvent type, salting out, and other factors on extraction efficiency were investigated. The results showed that the method performed well under the optimized experimental conditions when actual soils were used as real sample matrices. The accuracy and precision of the proposed method were verified. A total of 14 aniline and benzidine compounds demonstrated good linearities in the range of 0.5-100 mg/L. The method detection limits (MDLs) ranged from 0.02 to 0.07 mg/kg, and the limits of quantification (LOQs) ranged from 0.08 to 0.28 mg/kg. The target compounds were spiked at contents of 1 and 10 mg/kg. The spiked recoveries of the 14 targets in actual soils were 62.9%-101%, and the relative standard deviations (RSDs) of six precision tests were 3.8%-10.3%. The proposed method effectively inhibited the oxidation of aniline and benzidine compounds during extraction, and the target compounds exhibited high recoveries and good stabilities in the presence of three phases. Moreover, the operating procedure was simple and easy to implement. The proposed method was applied to the soil collected from an industrial enterprise in Jiangsu province that was suspected to be contaminated with aniline, and two aniline compounds were detected. The developed method requires a small sample size, and the preservation step is simple and effective. In addition, it can be applied to various types of actual soils. The method meets the requirements of current soil pollution risk control standards for aniline and benzidine compounds in soils.
PubMed: 38093543
DOI: 10.3724/SP.J.1123.2023.01002 -
Analytical Methods : Advancing Methods... Jan 2024Every year substandard and falsified (SF) artemisinin derivative-based antimalarials are responsible for the loss of 450 000 deaths and billions of GBP. The lack of...
Every year substandard and falsified (SF) artemisinin derivative-based antimalarials are responsible for the loss of 450 000 deaths and billions of GBP. The lack of infrastructure and funds to support pharmaceutical quality control in many low-and-middle-income countries contributes to this problem. This work assesses fitness for purpose of voltammetric methods for identification and quantification of artemether in the presence of excipients. Electrochemical characterization of artemether using cyclic voltammetry shows that the reduction of artemether is chemically irreversible within the potential range of -0.4 V to -1.4 V. A chronocoulometric quantification algorithm for artemether is created and tested with pure artemether, as well as filtered and unfiltered Riamet® tablets. Filtration of Riamet® tablets provides no additional benefit for the quantification of artemether in Riamet®. In addition, artemether's response to pH indicates possible protonation and coupled homogeneous chemistry. Finally, sodium sulfite is an effective means of removing dissolved oxygen and improving artemether signal resolution in air-equilibrated PBS. This concludes that electrochemical analysis is a promising method for artemether identification and quantification.
Topics: Antimalarials; Artemether; Artemisinins; Tablets; Quality Control
PubMed: 38088798
DOI: 10.1039/d3ay01837g -
Foods (Basel, Switzerland) Oct 2023Squid ink melanin can be efficiently extracted from the byproduct ink sac generated during squid processing. As a natural food colorant, it possesses inherent...
Squid ink melanin can be efficiently extracted from the byproduct ink sac generated during squid processing. As a natural food colorant, it possesses inherent antioxidant properties and the capability to adsorb heavy metals. This study aims to investigate the solubility of water-soluble squid ink melanin (WSSM) obtained from the ink sac, as well as its stability under various conditions including temperature, pH, salt, sugar, potassium sorbate, metal ions, sodium benzoate, sodium sulfite (reducing agent), and hydrogen peroxide (oxidizing agent). Moreover, it explores the scavenging effects of WSSM on free radicals and cadmium ions. The findings suggest that WSSM's stability is insignificantly affected by high temperature, sucrose, and salt. However, acidity, sodium benzoate, potassium sorbate, sodium sulfite (NaSO), and hydrogen peroxide (HO) significantly influence its stability. Most metal ions do not impact the stability of WSSM, except for Fe, Fe, Al, and Cu, which result in the precipitation of WSSM. Additionally, WSSM exhibits remarkable antioxidant activity with IC values of 0.91, 0.56, and 0.52 mg/mL for scavenging superoxide anion radicals (O·), hydroxyl radicals (·OH), and DPPH radicals, respectively. It also demonstrates the ability to adsorb the heavy metal Cd, with the adsorption rate gradually increasing with a higher temperature and larger amounts of WSSM added. Infrared spectroscopy analysis reveals the weakening of characteristic peaks (-COOH and -OH) during the process of Cd adsorption by WSSM, while SEM confirms surface roughening and structural damage after Cd adsorption. This study provides valuable insights for the utilization of squid melanin products as natural antioxidants and heavy metal adsorbents in the food industry.
PubMed: 37959093
DOI: 10.3390/foods12213963 -
ACS Omega Oct 2023In the present study, a biosorbent was prepared through the radiation-induced graft polymerization (RIGP) technique by using a glycidyl methacrylate (GMA) monomer....
In the present study, a biosorbent was prepared through the radiation-induced graft polymerization (RIGP) technique by using a glycidyl methacrylate (GMA) monomer. Functionalized bamboo materials were used for grafting. The grafting percentage (G %) of GMA on bamboo fibers was assessed based on the optimization of the absorbed dose and concentration of the monomer. The chemical modification of the polymerized product into the sulfonated form of the grafted biopolymer was carried out by using sodium sulfite solution. The modification of the biopolymer at various stages was analyzed by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques. By performing scanning electron microscopy (SEM), the morphological changes of the prepared biopolymer were analyzed. The temperature stability of the synthesized material was assessed by the thermogravimetric analysis (TGA) technique. The prepared sulfonated biosorbent was used in the batch adsorption study for the uptake of copper. We examined a variety of variables, including pH, adsorbent dosage, and time. The adsorption kinetics were studied using pseudo-first-order (PFO) and pseudo-second-order (PSO) models. Adsorption isotherms and thermodynamic parameters were also applied to study the adsorption capacity of the biosorbent. The maximum copper adsorption capacity was found to be 198 mg g from the Langmuir isotherm. Copper adsorption followed PSO kinetics ( = 0.999). This inexpensive and eco-friendly biosorbent removed 96% of copper ions from the solution.
PubMed: 37901518
DOI: 10.1021/acsomega.3c02466 -
JDS Communications Jul 2023Recently, the use of cocktail forage mixes in dairy cattle rations has become more common because the mixtures are low-cost, fit well in rotation after a cereal grain...
Recently, the use of cocktail forage mixes in dairy cattle rations has become more common because the mixtures are low-cost, fit well in rotation after a cereal grain forage, and can have similar yield and energy value compared with alfalfa silage. This experiment evaluated the effects of a chemical additive and packing density on the fermentation profile and nutrient composition of cocktail mix silage. The cocktail forage mix (brown-midrib sorghum-sudangrass, Italian ryegrass, red clover, berseem clover, and hairy vetch) was harvested, ensiled in laboratory silos (3.79-L plastic buckets), and allowed to ferment for 30 d. The experiment consisted of 6 treatments, 2 chemical additives [CON (30 mL of distilled water) or ADD (sodium sulfite, sodium metabisulfite, and fungal amylase)], and 3 packing densities [D100, D75, and D50 (100%, 75%, or 50% of the maximum material in laboratory silos, respectively)], for a total of 24 silos (4 replications per treatment combination). No interactions of additive by density were detected for any parameters evaluated. The addition of the chemical additive influenced fermentation profile, with reduced concentrations of total acids, lactic acid, acetic acid, and ethanol in ADD-treated silages. Moreover, D50 reduced concentrations of total acids, lactic acid, and acetic acid compared with D100, but had greater pH and yeast and mold counts. Minimal changes in nutrient composition were detected regardless of treatment. Overall, this study corroborates the importance of a well-packed silage during the ensiling process. Poorly packed cocktail mix silages may be more prone to spoilage based on yeast and mold counts.
PubMed: 37521068
DOI: 10.3168/jdsc.2022-0350