Potential nutritional and functional matters in yeast culture prepared by soybean meal fermentation.

BACKGROUND: Yeast culture (YC) is a product fermented on a specific medium, which is a type of postbiotic of anaerobic solid-state fermentation. Although YC has positive effects on the animal growth and health, it contains a variety of beneficial metabolites as dark matter, which have not been quantified. In the present study, liquid chromatography-tandem mass spectrometry is employed to identify the unknown metabolites. Following their identification, the important chemicals are quantified using HPLC-diode array detection methods. RESULTS: Non-targeted metabolomics studies showed that 670 metabolites in total were identified in YC, of which 23 metabolites significantly increased, including organic acids, amino acids, nucleosides and purines, isoflavones, and other substances. The chemical quantitative analysis showed that the contents of succinic acid, aminobutyric acid, glutamine, purine and daidzein increased by 84.42%, 51.07%, 100%, 68.85% and 4.60%, respectively. CONCLUSION: Therefore, the use of non-targeted metabolomics combined with chemical quantitative analysis to reveal the nutritional and functional substances of YC could help to elucidate the postbiotic mechanism and provide theoretical support for the regulation of the directional accumulation of beneficial metabolites. © 2024 Society of Chemical Industry.

Engineering Fluorine-rich Double Protective Layer on Zn Anode for Highly Reversible Aqueous Zinc-ion Batteries.

The high thermodynamic instability and side reactions of Zn-metal anode (ZMA), especially at high current densities, greatly impede the commercialization of aqueous zinc-ion batteries (AZIBs). Herein, a fluorine-rich double protective layer strategy is proposed to obtain the high reversibility of AZIBs through the introduction of a versatile tetradecafluorononane-1,9-diol (TDFND) additive in aqueous electrolyte. TDFND molecule with large adsorption energy (-1.51 eV) preferentially absorbs on the Zn anode surface to form a Zn(OR)2 - (R=-CH2 -(CF2 )7 -CH2 -) cross-linking complex network, which balances space electric field and controls the Zn2+ ion flux, thus enabling the uniform and compact deposition of Zn (002) crystal planes. Meanwhile, TDFND with low Lowest unoccupied molecular orbital (LUMO, 0.10 eV) energy level is priorly decomposed to regulate the interfacial chemistry of ZMA by building a ZnF2 -rich solid electrode/electrolyte interface (SEI) layer. It is found that a 14 nm-thick SEI layer delivers excellent structural integrity to suppress parasitic reactions by blocking the direct contact of active water and ZMA. Consequently, the Zn electrode exhibits a superior cycling life over 430 h at 10 mA cm-2 and a high average Coulombic efficiency of 99.8 % at 5 mA cm-2 . Furthermore, a 68 mAh pouch cell delivers 80.3 % capacity retention for 1000 cycles.

Phenolic compounds in germinated cereal and pulse seeds: Classification, transformation, and metabolic process.

Natural phenolic compounds are rich in cereal and pulse seeds and their dietary functions tend to improve dramatically during germination. This article reviews recent research on the transformation of phenolic compounds during seed germination. In particular, it highlights the classification of crude phenolic compounds that can be divided into extractable and non-extractable phenolic compounds based on the biosynthesis process and extraction method. It also recommends grouping resorcinol lipids in the category of extractable phenolic compounds as non-polar solvent extractable phenolic compounds. Moreover, it discusses the variation of the different form of phenolic compounds and proposes a possible metabolic model of these phenolic compounds for seeds germination. This article is crucial for phenolic compounds research, cereal and pulse seeds germination, and food ingredients industry.

High temperature spin-glass-like transition in La0.67Sr0.33MnO3 nanofibers near the Curie point.

The glassy transition of superparamagnetic (SPM) (r < r0) nanoparticle systems usually occurs at a very low temperature that greatly limits its application to high temperatures. In this work, we report a spin-glass-like (SGL) behavior near the Curie point (TC), i.e., T0 = 330 K, in La0.67Sr0.33MnO3 (LSMO) nanofibers (NFs) composed of nanoparticles beyond the SPM size (r ≫ r0), resulting in a significant increase of the glass transition temperature. This SGL transition near the TC of bulk LSMO can be explained to be the scenario of locally ordered clusters embedded in a disordered host, in which the assembly of nanoparticles has a magnetic core-shell model driven by surface spin glass. The presence of a surface spin glass of nanoparticles was proved by the Almeida-Thouless line δTf ∝ H2/3, exchange bias, and reduced saturation magnetization of the NF system. Composite dynamics were found - that is, both the SPM and the super-spin-glass (SSG) behavior are found in such an NF system. The bifurcation of the zero-field-cooled (ZFC) and field-cooled (FC) magnetization vs. temperature curves at the ZFC peak, and the flatness of FC magnetization involve SSG, while the frequency-dependent ac susceptibility anomaly follows the Vogel-Fulcher law that implies weak dipole interactions of the SPM model. This finding can help us to find a way to search for high temperature spin glass materials.

Simulating magnetic nanotubes using a chain of ellipsoid-rings model with a magnetization reversal process by fanning rotation.

Recently, magnetic nanotubes have attracted great attention owing to the advantages of tubular geometry. Of all the physical properties of magnetic nanotubes, the magnetic behavior plays a pivotal role in potential applications, particularly in biotechnology. Modeling magnetic nanotubes provides an effective way to determine the geometry dependent magnetic properties. In the present article, we model the nanotube as a chain of ellipsoid-rings; thus the magnetic behavior of nanotubes is simulated by the fanning rotation of magnetic moments. Based on this model, we further discuss the influence of tubular geometric parameters on the magnetic properties. The calculated magnetic properties of Fe, Co, Ni, Fe3O4 and CoFe2O4 nanotubes are all consistent with their experimental data. Consequently, our model provides an easy and general approach to magnetic nanotubes.

Effect of xanthan gum (XG) and carrageenan (CG) ratio on casein (CA)-XG-CG ternary complex: Used to improve the stability of liquid diabetes formula food for special medical purposes.

Poor storage stability limits the application of liquid diabetes formula food for special medical purposes (L-D-FSMP) in maintaining blood sugar stability in diabetic patients. This work aims to improve the stability of L-D-FSMP by adjusting the ratio of xanthan gum (XG) and carrageenan (CG) in casein (CA)-XG-CG ternary complex. The centrifugal sedimentation rate results showed that the compound ratio of XG and CG had a greater impact on L-D-FSMP storage stability. Transmission electron microscopy (TEM) results showed that the combination of CA, XG and CG occurred. Fourier transform infrared spectroscopy (FTIR) results showed that CA, XG and CG were mainly combined through hydrogen bonds and ionic bonds to form a CA-XG-CG ternary complex. When the ratio of XG and CG was 1:1, the number of disulfide bonds was the largest. The results of three-phase contact angle and emulsifying ability confirmed that when the ratio of XG and CG was 1:1, CA-XG-CG had the strongest emulsifying ability. The particle size distribution and zeta-potential results showed that when the ratio of XG and CG was 1:1, L-D-FSMP had the narrowest particle size distribution range and the strongest stability. These results may provide valuable information for the production of stable L-D-FSMP.

Structural characteristics and emulsifying properties of linear dextrin/eicosapentaenoic acid composites: Effect of the degree of polymerization.

This work aimed at building functional emulsions based on the linear dextrins (LDs) emulsion system. The gradient polyethylene glycol (PEG) precipitaion method was used to fractionate LDs into fractions with different degrees of polymerization (DP). A package, and co-precipitation procedure of LDs, and eicosapentaenoic acid (EPA) was used to fabricate LDs-EPA composites. The gas chromatograph, Fourier transform infrared spectroscopy, X-ray diffraction and differential scanning calorimetry analyses affirmed the formation of the LDs-EPA composites. The sizes of these composites were 38.55 nm, 59.14 nm to 80.62 nm, respectively, and they had good amphiphilicity. Compared with LDs, these LDs-EPA composites stabilized Pickering emulsion had higher stability and antioxidant capacity. Their emulsifying ability was positively correlated with the DP values of LDs. Furthermore, the oxidation stability results showed that LDsF10-EPA emulsion had the lowest lipid hydroperoxide (LHs) content, malondioxide (MDA) content and hexal concentration, which were 138.75 mmol kg-1 oil, 15.50 mmol kg-1 oil and 3.83 µmol kg-1 oil, respectively. The study provided a new idea and application values for the application of LDs in emulsion.

Spectroscopy combined with spatiotemporal multiscale strategy to study the adsorption mechanism of soybean protein isolate with meat flavor compounds (furan): Differences in position and quantity of the methyl.

The interaction mechanism between soybean protein isolate (SPI) and furan flavor compounds with different structures is studied using spectroscopy, molecular docking, and MD simulation methods. The order of binding ability between SPI and furan flavor compounds is 2-acetylfuran>furfural>5-methylfurfural. The structural differences (position and quantity of methyl groups) of three furan flavor compounds are key factors leading to the different adsorption abilities of SPI for furan flavor compounds. The findings from spectroscopy analyses suggest that the interaction between SPI and furan flavor compounds involves both static and dynamic quenching mechanisms, with static quenching being the main factor. Molecular docking and MD simulations reveal the atomic-level mechanisms underlying the stable binding for SPI and furan flavor compounds at spatiotemporal multiscale. This study provides a theoretical framework for the production and adjustment of meat essence formula in the production of soybean protein-based meat products.

Sensory profile of pulse-based high moisture meat analogs: A study on the complex effect of germination and extrusion processing.

Germination and extrusion are two processes that could affect beany flavors in pulse-based high-moisture meat analogs (HMMAs). This research studied the sensory profile of HMMAs made by protein-rich flours from germinated/ungerminated pea and lentil. Air-classified pulse protein-rich fractions were processed into HMMAs with twin screw extrusion cooking, optimized at 140 °C (zone 5 temperature) and 800 rpm screw speed. Overall, 30 volatile compounds were identified by Gas Chromatography-Mass Spectrometry/Olfactory. Chemometric analysis exhibited that the extrusion markedly (p < 0.05) reduced beany flavor. A synergistic effect of germination and extrusion process was observed, decreasing some beany flavors such as 1-octen-3-ol and 2,4-decadienal, and the overall beany taste. Pea-based HMMAs are suitable for lighter, softer poultry meat, while lentil-based HMMAs are suited for darker, harder livestock meat. Those findings offer novel insights into the regulation of beany flavors, odor notes, color, and taste to improve the sensory quality of HMMAs.

Acidic enol electrooxidation-coupled hydrogen production with ampere-level current density.

Hydrogen production coupled with biomass upgrading is vital for future sustainable energy developments. However, most biomass electrooxidation reactions suffer from high working voltage and low current density, which substantially hinder large-scale industrial applications. Herein, we report an acidic hydrogen production system that combined anodic ascorbic acid electrooxidation with cathodic hydrogen evolution. Unlike C-H and O-H bonds cleavage with slow kinetics in conventional organic oxidation, the highly active enol structure in ascorbic acid allows for an ultralow overpotential of only 12 mV@10 mA/cm2 using Fe single-atom catalysts, and reaches 1 A/cm2 at only 0.75 V (versus reversible hydrogen electrode) with approximately 100% Faraday efficiency for hydrogen production. Furthermore, the fabricated two-electrode membrane-free electrolyser delivers an industrial current density of 2 A/cm2@1.1 V at 60 °C (2.63 kWh/Nm3 H2), which requires half of the electricity consumption in conventional water electrolysis (~5 kWh/Nm3 H2). This work provides a new avenue for achieving industrial-scale hydrogen production from biomass.

Design and Synthesis of a π-Conjugated N-Heteroaromatic Material for Aqueous Zinc-Organic Batteries with Ultrahigh Rate and Extremely Long Life.

Electroactive organic materials with tailored functional groups are of great importance for aqueous Zn-organic batteries due to their green and renewable nature. Herein, a completely new N-heteroaromatic material, hexaazatrinaphthalene-phenazine (HATN-PNZ) is designed and synthesized, by an acid-catalyzed condensation reaction, and its use as an ultrahigh performance cathode for Zn-ion batteries demonstrated. Compared with phenazine monomer, it is revealed that the π-conjugated structure of N-heteroaromatics can effectively increase electron delocalization, thereby improving its electrical conductivity. Furthermore, the enlarged aromatic structure noticeably suppresses its dissolution in aqueous electrolytes, thus enabling high structural stability. As expected, the HATN-PNZ cathode delivers a large reversible capacity of 257 mAh g-1 at 5 A g-1 , ultrahigh rate capability of 144 mAh g-1 at 100 A g-1 , and an extremely long cycle life of 45 000 cycles at 50 A g-1 . Investigation of the charge-storage mechanism demonstrates the synergistic coordination of both Zn2+ and H+ cations with the phenanthroline groups, with Zn2+ first followed by H+ , accompanying the reversible formation of zinc hydroxide sulfate hydrate. This work provides a molecular-engineering strategy for superior organic materials and adds new insights to understand the charge-storage behavior of aqueous Zn-organic batteries.

Barley Husk Degraded by Fusarium graminearum MH1 Induced Premature Yeast Flocculation.

Premature yeast flocculation (PYF) is one of the pivotal problems affecting beer flavor and production. PYF is induced by certain non-starch polysaccharides produced by the degradation of malted barley husks upon the growth of contaminated microorganisms, such as Fusarium graminearum. In this research, the formation mechanism of PYF was uncovered by investigating the secretome of F. graminearum MH1 inoculated to the barley husk. The polysaccharide extract of degraded husk was ultrafiltrated into four fractions and characterized by the minimum PYF concentration, molecular mass distribution, monosaccharide composition, and zeta potential. Among the four fractions, the high-molecular-weight polysaccharide fraction had the highest content of uronic acid and the most negative zeta potential, which contributed to the most severe PYF phenomenon. In addition, the PYF yeast showed a more negative zeta potential than the control yeast during the small-scale brewing process. This is aligned to the negatively charged polysaccharides potentially bonded to the surface of yeast cells through the calcium cation in the same fermentation system, which results in rapid flocculation and precipitation. Approximately 12% of the 214 proteins identified in the Fusarium graminearum MH1 secretome were hemicellulases, which substantially interpreted the mechanism of polysaccharides inducing PYF yeast during beer brewing.

Enhancement of substrate concentration in microbial stereoinversion through one-pot oxidation and reduction by aqueous two-phase system.

An extractive biocatalytic method of aqueous two-phase system was employed for stereoinversing (R)-1-phenyl-1,2-ethanediol into (S)-1-phenyl-1,2-ethanediol by Candida parapsilosis CCTCC M203011. It was observed that substrate and product inhibitions in microbial stereoinversion through one-pot oxidation and reduction were removed efficiently by extractive biocatalysis in aqueous two-phase system with PEG 4000/phosphate potassium system, and that the substrate concentration was enhanced from 15 to 30 g/L with product optical purity of 99.02% e.e. and yield of 90% after 60 h. Simultaneously, it was observed that change in cell morphology impedes the further enhancement of substrate concentration in this system but can be reversibly changed after stereoinversion or cultivation in systems without PEG.

Unlocking the potential of minimally processed corn germ oil and high oleic soybean oil to prepare oleogels for bakery application.

In this study, the influence of sunflower wax (SFX) concentration (1, 3, 5, 7, and 9 wt%) on the properties of oleogels prepared using expeller-pressed corn germ oil (EPC) or high oleic soybean oil (EPS) was comprehensively investigated. Overall, oleogels can be prepared from both EP oils at an SFX level ≥3 wt%. The strength of oleogels depends on SFX concentration. EPS oleogels had better rheological properties and a higher amount of platelet-like crystals than EPC oleogels. The characteristics of cookies prepared with both oleogels were evaluated and compared to cookies prepared with commercial shortening. The lipid distribution in the cookies as visualized by CLSM suggested that EPS oleogels with a 5 or 7 wt% SFX had a greater possibility of replacing commercial shortening as they exhibited even lipid distribution which enabled good air-incorporation and air retention abilities. This research provides a foundation for developing healthy bakery products by using minimally processed oil based oleogels.

Changes in odor characteristics of pulse protein isolates from germinated chickpea, lentil, and yellow pea: Role of lipoxygenase and free radicals.

In this study, pulse protein isolates (PPIs) were extracted from 0, 1, 3, and 5 days germinated chickpea, lentil, and yellow pea flours by alkaline extraction-isoelectric precipitation method. The germination time had negligible impact on the proximate composition of PPIs. In total, 67 volatiles in PPIs were identified via HS-SPME-GC-MS/O. Among all the identified volatile components, seven of them, including hexanal (11), (E)-2-octen-1-ol (7), (E,Z)-2,6-nonadienal (17), 3-octen-2-one (33), 3,5-octadien-2-one (34), 2-methoxy-3-isopropylpyrazine (56), and 2-methoxy-3-(1-methylpropyl)pyrazine (57), contributed to the beany-related odor of PPIs but much less than that in raw flours. However, the overall beany-related odor of PPIs increased when the germination time exceeded 1 day. Both the activity of lipoxygenase and the free radical populations in PPIs were positively related to the overall beany-related odor. Our findings are crucial for the preparation of germinated pulse proteins with improved functionality but without increasing undesirable odor.

Optimization and validation of in-situ derivatization and headspace solid-phase microextraction for gas chromatography-mass spectrometry analysis of 3-MCPD esters, 2-MCPD esters and glycidyl esters in edible oils via central composite design.

This study aimed to develop a headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) method for the quantification of 3-monochloropropane-1,2-diol fatty acid esters (3-MCPDEs) and 2-monochloropropane-1,3-diol fatty acid esters (2-MCPDEs), and semi-quantification of glycidyl fatty acid esters (GEs) in edible oils. A central composite design was implemented to optimize the derivatization temperature and extraction time, which were 100 °C and 80 min, respectively. HS-SPME coupled with in-situ derivatization was more straightforward (three steps) and sensitive, with a limit of detection of 16% (3.9 µg/L) and 11% (5.3 µg/L) higher than that of liquid injection method, for 3-MCPD and 2-MCPD, respectively. The recoveries of 3-MCPD and 2-MCPD were in the range of 91.1% to 102.1%, with a relative standard deviation ranging from 0.08 to 9.29%. The validated methodology was successfully applied to oil samples. Further efforts will focus on shortening the extraction time, as 80 min is relatively long.

HS-SPME-GC-MS/olfactometry combined with chemometrics to assess the impact of germination on flavor attributes of chickpea, lentil, and yellow pea flours.

In this study, volatile component changes of germinated chickpea, lentil, and yellow pea flours over the course of 6 days germination were characterized by HS-SPME-GC-MS/O. In total, 124 volatile components were identified involving 19 odor active components being recorded by GC-O exclusively. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed that lentil and yellow pea flours had the similar aromatic attributes, while the decrease of beany flavor compounds along with the occurrence of unpleasant flavors was detected in chickpea flours upon germination. Six beany flavor markers, including hexanal, (E,E)-2,4-nonadienal, (E,E)-2,4-decadienal, 3-methyl-1-butanol, 1-hexanol, and 2-pentyl-furan, were employed to quantify beany flavor formation in the flours over the course of germination. The results suggested that no significant beany flavor formation or mitigation was appeared after 1 day of germination. The findings are crucial for tailing pulse germination process to enhance the macronutrients without increasing undesirable beany flavor.

Effect of germination time on antioxidative activity and composition of yellow pea soluble free and polar soluble bound phenolic compounds.

This research aims to study antioxidative activities of polar solvent extractable phenolic compounds from yellow peas with different germination times against oil-in-water emulsion oxidation. After germination (0, 2, 4, and 6 days), soluble free and polar soluble bound phenolic compounds were extracted and their antioxidative activity was evaluated using stripped soybean oil (SSO)-in-water emulsions. Liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS) and size-exclusion chromatography with multiangle-light-scattering and refractive-index detection (SEC-MALS-RI) were employed to analyze the phenolic composition and molar mass, respectively. Antioxidative activities of soluble free phenolic compounds increased in the SSO-in-water emulsion system, while those of polar soluble bound phenolic compounds decreased with germination. On the basis of chemometric analysis, pratensein (2), phloridzin (4), quercetin (9), sayanedine (12), hesperetin (13), glyzaglabrin (14), and pinocembrin (15) were speculated as the pivotal phenolic compounds responsible for the hydrogen donating capacity. Additionally, decreased molecular weight of soluble bound phenolic compounds was accompanied by the reduction of antioxidative activity in SSO-in-water emulsions indicating that the moieties of polar soluble bound phenolic compounds also have an important impact on the antioxidative activity of phenolic compounds.

Solid dispersion-based spray-drying improves solubility and mitigates beany flavour of pea protein isolate.

Recently, there is a strong interest in incorporation of pea protein as a preferred alternative to animal protein into protein-fortified food. However, the utilization of pea protein as a food ingredient has been largely limited because of its poor functionality. The aim of this study was to understand if solid dispersion-based spray-drying processing could be applied to enhance the solubility and mitigate off-flavour in pea protein isolate (PPI). The influence of amorphous matrix carrier type (gum arabic and maltodextrin), and PPI to carrier ratio (90:10-60:40) on physical properties, solubility, and off-flavour profile of PPI was investigated. The results demonstrated the possible mechanism by which factors such as surface area/volume ratio, hydrogen bonding, and electrostatic interaction between PPI and carriers enhance PPI solubility. Meanwhile, beany flavours were mitigated through the unfolding of secondary structure of PPI by forming solid dispersions with gum arabic or maltodextrin during spray-drying.

Effect of germination on the chemical composition, thermal, pasting, and moisture sorption properties of flours from chickpea, lentil, and yellow pea.

Chemical composition, thermal, pasting, and moisture adsorption properties of flours from chickpea (Cicer aretinium L.), lentil (Lens culinaris Merr.), and yellow pea (Pisum sativum L.) were investigated over a 6-day germination. Protein content increased for pulses over germination while lentil had the highest protein content that increased from 30.65 to 33.60 g/100 g dry basis (d.b.). Lipid content in pulse flours decreased over germination with chickpea having the greatest decline, i.e. from 8.00 to 5.90 g/100 g (d.b.). Total starch decreased in lentil and yellow pea flours during germination, while there was no significant change (p > 0.05) in germinated chickpea flours. Thermal properties of pulse flours changed slightly, while pasting properties varied among pulses. The highest final viscosities for chickpea, lentil, and yellow pea flours were 1061, 981, and 1052 cP and were observed after 2, 1, and 0 days of germination, respectively. Moisture adsorption isotherms showed improved water adsorption capability after germination.