Spectrometry Profiling Research Articles

Unveiling full-dimensional distribution of trap states toward highly efficient perovskite photovoltaics

To gain a deep understanding and address key issues in perovskite photovoltaics, such as power conversion efficiency (PCE) and long-term stability, defect passivation and analysis of the device performance are required. Here, we proposed a non-contact characterization technique named scanning photocurrent measurement system (SPMS) for device surface detection, having conducted signal analysis and method adjustments based on perovskite photovoltaic devices. This technique enables the monitoring of minority carriers in the device, allowing for the investigation of carrier behavior based on photocurrent signals. By integrating SPMS with thermal conductance spectroscopy (TAS) and drive-level capacitance profiling (DLCP), we further simulated a spatial three-dimensional (3D) distribution of trap states in the device and analyzed the distribution of trap states matched with energy space. Through extensive case studies, we have validated the universality and accuracy of this method. The integration of trap state characterization techniques provides strong support for targeted defect passivation and performance evaluation of perovskite photovoltaic devices, yielding a highly efficient perovskite solar cell with PCE as high as 25.74%.

Low-Temperature Selective Si:As Epitaxy

A selective low-temperature Si:As (LT-SiAs) process is presented which utilizes cyclic deposition-etch (CDE) at <450oC. Selectivity against SiN and SiOx dielectrics and crystallinity are confirmed on gate-all-around (GAA) patterned structures. Hall measurements on blanket wafers show a resistivity minimum of 0.42 mΩ-cm at ~1.7% As for selective LT-SiAs. Secondary-ion mass spectroscopy (SIMS) profiles of P and As diffusion into intrinsic Si (i-Si) for LT-SiP/LT-SiAs/i-Si and LT-SiP/i-Si stacks show >2× benefit of using LT-SiAs spacers to minimize dopant diffusion for as-deposited, soak-annealed and spike-annealed samples. Improvement is attributed to relatively limited diffusivity of As in Si versus P and the lower As concentration needed for LT-SiAs layer to achieve minimum resistivity relative to LT-SiP (~3%). Lastly, a comparison of LT-SiAs and high-temperature Si:As (HT-SiAs) shows a ~2× reduction of As diffusion into i-Si for LT-SiAs at length scales of >10nm.

Blunted Cardiac Mitophagy in Response to Metabolic Stress Contributes to HFpEF.

Metabolic remodeling and mitochondrial dysfunction are hallmarks of heart failure with reduced ejection fraction. However, their role in the pathogenesis of HF with preserved ejection fraction (HFpEF) is poorly understood. In a mouse model of HFpEF, induced by high-fat diet and Nω-nitrol-arginine methyl ester, cardiac energetics was measured by 31P NMR spectroscopy and substrate oxidation profile was assessed by 13C-isotopmer analysis. Mitochondrial functions were assessed in the heart tissue and human induced pluripotent stem cell-derived cardiomyocytes. HFpEF hearts presented a lower phosphocreatine content and a reduced phosphocreatine/ATP ratio, similar to that in heart failure with reduced ejection fraction. Decreased respiratory function and increased reactive oxygen species production were observed in mitochondria isolated from HFpEF hearts suggesting mitochondrial dysfunction. Cardiac substrate oxidation profile showed a high dependency on fatty acid oxidation in HFpEF hearts, which is the opposite of heart failure with reduced ejection fraction but similar to that in high-fat diet hearts. However, phosphocreatine/ATP ratio and mitochondrial function were sustained in the high-fat diet hearts. We found that mitophagy was activated in the high-fat diet heart but not in HFpEF hearts despite similar extent of obesity suggesting that mitochondrial quality control response was impaired in HFpEF hearts. Using a human induced pluripotent stem cell-derived cardiomyocyte mitophagy reporter, we found that fatty acid loading stimulated mitophagy, which was obliterated by inhibiting fatty acid oxidation. Enhancing fatty acid oxidation by deleting ACC2 (acetyl-CoA carboxylase 2) in the heart stimulated mitophagy and improved HFpEF phenotypes. Maladaptation to metabolic stress in HFpEF hearts impairs mitochondrial quality control and contributed to the pathogenesis, which can be improved by stimulating fatty acid oxidation.

Influence of Dy3+ doping on Mössbauer, magnetic and microwave absorption properties of M-type Ba0.5Ca0.5DyxFe12-xO19 hexaferrites

The present research paper reports a systematic study of the magnetic, and structural properties of Ba0.5Ca0.5DyxFe12-xO19 M-type hexaferrite. The dysprosium was doped @ x = 0 − 0.2, keeping Δx = 0.05, in BCDF by the sol–gel self-ignition technique. The sintering of the synthesized samples was performed for 4 h at 1050°C. The crystallographic analysis of the samples was made from the X-ray diffractograms (XRD), while the morphological and elemental analysis was made from field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray spectroscopy (EDAX) profiles. The structural results revealed the formation of the M-type hexaferrite having P63/mmc as a space group along with the co-existence of a secondary Fe2O3 phase. FESEM micrographs exhibit the hexagonal platelets randomly arranged with agglomerations at some places giving rise to the random variations in particle size with varying ’x’. Magnetic measurements (VSM) show that the saturation magnetization (MS) and coercivity (HC) increase with the increasing Dy3+ doping pointing towards the fact that the Dy doping in Ba-Ca ferrite can be used to fabricate the hard ferrites with good saturation magnetization. The Mössbauer spectrum recorded at room temperature reveals five superimposed sextets representing the five Fe3+ ion sites. Investigating the Microwave absorption (MWA) characteristics in the frequency range 8 − 12 GHz (X-band), reveals that the sample with x = 0.1 having 3 mm thickness possesses good MWA power. Its minimum RL value for matching frequency 10.06 GHz is approximately −26.96 dB, indicating that more than 90 % of microwaves are absorbed. The current work offers the Dysprosium-doped BCDF hexaferrites, as promising candidatesfor microwave absorption applications.

Carbonized Polymer Dots: Influence of the Carbon Nanoparticle Structure on Cell Biocompatibility.

Carbonized polymer dots (CPDs) were obtained by using microwave irradiation under the same conditions. However, different carbogenic precursors were used, such as aromatic diamine molecules, ortho-phenylenediamine (o-OPDA), and 3,4-diaminobenzoic acid (3,4-DABA). Both carbon nanoparticles showed different structural results based on Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and atomic force microscopy analyses. However, there are similar spectroscopic (UV-visible and fluorescence emission) profiles. The photophysical results, like quantum yield (QY) and fluorescence lifetime, were not identical; CPDs-OPDA has a higher QY and fluorescence lifetime than CPDs-3,4-DABA. CPDs-3,4-DABA presents a more hydrophobic character than CPDs-OPDA and has a more negative superficial charge. Cell viability studies in both standard and tumor lines demonstrated higher cytotoxicity from CPDs-OPDA than that from CPDs-3,4-DABA. The oxidative stress identified in cells treated with CPDs-OPDA was based on reactive oxygen species and associated with nitric oxide production. CPDs-3,4-DABA showed more DPHH inhibition than CPDs-OPDA, indicating the antioxidant activity of CPDs.

Chitosan grafted with gallic acid and cerium dioxide hybrid nanocomposites as environmentally friendly corrosion inhibitors for mild steel: An experimental and computational study

Chitosan grafted with gallic acid (CS-GA), along with CS-GA doped with CeO2 nanoparticles (CS-GA-CeO2) were synthesized as novel environmentally friendly mild steel corrosion inhibitors. The formation of these derivatives was confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), hydrogen nuclear magnetic resonance spectroscopy (1H NMR), and thermal analysis (TGA). Based on potentiodynamic polarization curves (PDP) measurements, the inhibitors acted primarily as hybrid inhibitors, while following the Langmuir adsorption theory model. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy(XPS) and 3D surface profiles, confirmed that CS-GA-CeO2 adsorbed on the mild steel forming a protective layer thus preventing the invasion of corrosive media. The corrosion protection mechanism of chitosan derivatives was investigated by molecular dynamics simulations. Electrochemical measurements were used to investigate the corrosion inhibition by CS-GA and CS-GA-CeO2 on mild steel in a 3.5 % NaCl solution. At room temperature, the highest inhibition efficiency (93.58 %) was achieved at 200 ppm CS-GA-CeO2. Modified chitosan nanocomposites were confirmed as promising corrosion inhibitors.

Effect of ageing and cataract formation on the Raman spectroscopic profile of human lens: An observational study.

To observe the spectroscopic profile of human lens in different age groups and varying grades of cataract and to use the data to arrive at differentiating molecular biology. An observational cross-sectional study. The study enrolled 30 patients (30 eyes) with a mean age of 59.6 years diagnosed with immature senile cataracts. The patients underwent small incision cataract surgery, and the harvested lens nuclei were examined under a Raman spectroscope for studying their molecular composition. The relative intensities of the peaks in the Raman spectra were evaluated and compared among different age groups and grades of cataract. A correlation of tyrosine doublet ratio with grade of cataract and age of the subject was calculated. Several Raman spectral peaks were observed in the range of 600 cm-1 to 1800 cm-1 with correspondence to tyrosine, phenylalanine, tryptophan, and amides I and III. A strong negative correlation between the grade of cataract and the ratio of tyrosine doublet was seen (r = -0.805). Also, a negative correlation between age and tyrosine ratio was seen (r = -0.62). The wavenumber/spectral peak of tryptophan was observed only in one sample, and amides I and III were identified, but the intensity of the peak for amide II was very small or absent. It was observed that the buried conformation of tyrosine was predominant in cases with a higher age or grade of cataract. The buried conformation of tryptophan became less in the higher grades of cataract.

Adsorbents Produced from Olive Mill Waste and Modified to Perform Phenolic Compound Removal

Olive mill waste (olive pomace, OP, and olive stone, OS) was used in this work to produce adsorbents for the removal of five phenolic acids typically found in olive mill wastewater. OP and OS were subjected to different treatments (combined or not) that were chemically modified (NaOH) or physically modified by two different methods, incipient wetness impregnation (IWI) and hydrothermal deposition (HD), and even biochar production obtaining a total of 16 materials. The materials were characterized by different analytical techniques such as N2 absorption, scanning electron microscopy, infrared spectroscopy, and pH zero-potential charge. The mixture of five phenolic acids was used to evaluate in batch conditions the adsorption capacity of the prepared materials. OS chemically modified with IWI (OSM-IWI) and OS biochar with HD (BOS-HD) presented better adsorption capacity at 157.1 and 163.6 mg/g of phenolic acids, respectively, from a total of 200 mg/g. For some materials, the surface area cannot be correlated with adsorption capacity, unlike pHzpc, where high values fit better adsorption rates. The infrared spectroscopy profile indicates the presence of O-H and N-H functional groups and, the last one, red-shifted in the IWI preparation compared to the HD one. In addition to this, the prepared material from olive mill waste can be suitably used for the mixture of phenolic compounds.

Synthetic V(V)-peroxido-zwitterionic species catalyze benzene oxidation under mild reaction conditions

A series of dinuclear complexes were synthesized, involving vanadium with N-methylglycine (sarcosine)/N,N’-dimethylglycine in aqueous media and H2O2, capable of exerting catalytic activity. Specifically, the ternary V(V) tetraperoxido dinuclear species (NH4)2[V2O2(O2)4(CH3NH2CH2COO)] (symmetric conformer) (1), (NH4)2[V2O2(O2)4(CH3NH2CH2COO)] (asymmetric conformer) (2), K2(Η2Ο)[V2O2(O2)4(CH3NH2CH2COO)] . H2O (3) (asymmetric conformer), and K2(Η2Ο)2[V2O2(O2)4{(CH3)2NHCH2COO)}] (4) (asymmetric conformer) were synthetically isolated in crystalline form. Compounds 1 and 2 are the same, whilst with profound conformational differences exemplified through pH-specific chemistries. The new materials 1–4 were characterized by elemental analysis, FT-IR, Raman, NMR, and UV–Visible spectroscopy, cyclic voltammetry, thermogravimetric analysis (TGA-DTG), and X-ray crystallography. Further support of the spectroscopic and structural profile was achieved through Bond Valence Sum (BVS) and Hirshfeld molecular mapping calculations. In all of the studied compounds, pH appears to be a crucial factor in the synthesis and isolation. The physicochemical characterization of the hybrid materials justified further use of compound 3 as a potential hydroxylation catalyst of benzene under a variable set of mild reaction conditions. The products of the catalytic reaction systems investigated were identified and quantified by gas chromatography–mass spectrometry (GC-MS) and gas chromatography–flame ionization detection (GC-FID), respectively. The results a) exemplify the involvement of the hybrid dinuclear vanadium compounds in the pursued benzene transformations, and b) distinctly demonstrate the structural and chemical characteristics justifying the emergence of catalytic action of vanadium under mild conditions (40 °C) in reactions toward organic substrates (e.g. benzene) as the basis for the pursuit of selective industrial applications, affording readily available useful compounds.

Physicochemical, Functional, Antioxidant, Pasting and FT-IR Spectroscopic Properties of Fermented Acorns and Sorghum Using Traditional Algerian Processes

The fermentation of acorns and sorghum is an ancient practice among the inhabitants of northeastern Algeria. This study aimed to establish the traditional fermentation processes of acorns and sorghum through a regional survey conducted in Algeria. Additionally, it investigated the impact of fermentation on the physicochemical, functional, antioxidant, and pasting properties, as well as the FT-IR spectroscopic profiles of the flours derived from these fermented materials. Characteristics of fermented sorghum and acorn flours were compared with those of non-fermented flours. The study included a survey that was carried out in Algeria at the regional level to establish the traditional processes for fermented acorns and sorghum. The key findings reveal the existence of two production methods: the first, the oldest, involves fermentation in underground pits called Matmor, while the second, more recent, is conducted outside the Matmor. Most manufacturers employed the new process outside of the Matmor, usually in various sized and shaped containers to meet market demand. Acorns and sorghum flour, obtained by drying and grinding fermented acorns and fermented sorghum grains according to the process carried out outside the Matmor, are characterized by a unique biochemical, functional, and structural composition. Detailed analysis of the flours showed a significant decrease in their physicochemical properties after fermentation, with a simultaneous overall increase in antioxidant activity. Moreover, FT-IR spectroscopy suggests that fermentation differentially affects protein secondary structure and starch crystallinity.

SOILS IN FORENSIC ANALYSIS: A REVIEW

This review article highlights article highlights the crucial role of soil in forensic investigations, showcasing its ability to connect suspects, victims, and crime scenes. In the present scenario, the importance of this work is underscored by the increasing complexity of criminal activities and the growing need for precise forensic methods. As environmental conditions and land use patterns change, understanding soil characteristics and their forensic applications becomes even more crucial. Through advanced analysis techniques like spectroscopy and DNA profiling, soil becomes a valuable tool for solving crimes, tracing geographical origins, and providing crucial evidence, reinforcing its importance in modern forensic science. This review showcases soil as a powerful, often overlooked tool in solving crimes and bringing justice, despite challenges like soil variability and contamination.

High-Throughput Single-Molecule Surface-Enhanced Raman Spectroscopic Profiling of Single-Amino Acid Substitutions in Peptides by a Gold Plasmonic Nanopore.

Simultaneous detection and structural characterization of protein variants on a single platform are highly desirable but technically challenging. Herein, we present a single-molecule spectral system based on a gold plasmonic nanopore for analyzing two peptides and their single-point mutated variants. The gold plasmonic nanopore enabled the high-throughput acquisition of surface-enhanced Raman scattering (SERS) spectra at the single-molecule level by electrically driving analytes into hot spots. Furthermore, a statistical method based on Boolean operations was developed to extract prominent features from fluctuated single-molecule SERS spectra. The effects of the single-amino acid substitutions on both the intramolecular interactions and the peptide conformations were directly characterized by the nanopore system, and the results agreed with the predictions by AlphaFold2. This study highlights the mutual benefits of spectroscopy and nanopore technology, whereby the gold plasmonic nanopore offers a powerful tool for the structural analysis of single-molecule proteins.

Artificial intelligence-based plasma exosome label-free SERS profiling strategy for early lung cancer detection.

As a lung cancer biomarker, exosomes were utilized for in vitro diagnosis to overcome the lack of sensitivity of conventional imaging and the potential harm caused by tissue biopsy. However, given the inherent heterogeneity of exosomes, the challenge of accurately and reliably recognizing subtle differences in the composition of exosomes from clinical samples remains significant. Herein, we report an artificial intelligence-assisted surface-enhanced Raman spectroscopy (SERS) strategy for label-free profiling of plasma exosomes for accurate diagnosis of early-stage lung cancer. Specifically, we build a deep learning model using exosome spectral data from lung cancer cell lines and normal cell lines. Then, we extracted the features of cellular exosomes by training a convolutional neural network (CNN) model on the spectral data of cellular exosomes and used them as inputs to a support vector machine (SVM) model. Eventually, the spectral features of plasma exosomes were combined to effectively distinguish adenocarcinoma in situ (AIS) from healthy controls (HC). Notably, the approach demonstrated significant performance in distinguishing AIS from HC samples, with an area under the curve (AUC) of 0.84, sensitivity of 83.3%, and specificity of 83.3%. Together, the results demonstrate the utility of exosomes as a biomarker for the early diagnosis of lung cancer and provide a new approach to prescreening techniques for lung cancer.

Bioprospecting for moderately halophilic eubacteria for potential biotechnological applications from Sambhar Lake, Rajasthan, India

Sambhar Lake an athalassohaline habitat located at 27°58′N 75°55′E, Rajasthan, India is a major source of salt production in the country. From surface lake water, soil, and shore sediments, fifty-nine moderate halophiles were isolated which were subsequently grouped according to shape, colony characteristics, and staining into twenty-two isolates. Fourier transform infrared spectroscopy profiling identifiedthese isolates as eubacterial with characteristic C=O stretching of ester functional groups. Observations further indicatedsimilarity within some Halomonasisolates indicating potential phylogenetic lineages. The FASTA sequences obtained after sequencing with universal bacterial primers were processed for phylogenetic analysis. Predominantly Gram-positive genera like Alkalibacillus, Amphibacillus, Marinococcus, Piscibacillus, Planococcus, Salinicoccus, Staphylococcusand Virgibacilluswith only two Gram-negative strains of Halomonaswere identified. The genus Amphibacilluswas recognizedfor the first time in the study of Sambhar Lake. Despite being moderately halophilic, several isolates exhibited high salt tolerance with growth in 25% salt. All isolates were mesophilic with growth observed between 18-42°C which matches the temperature profile of the region. Analysis of hydrolytic potential identified eighteen isolates as protease producers, thirteen as lipase producers, and ten as cellulase-producing strains. Further evaluation showed the dominance of C10:0, C12:0, C13:0, C14:0, C15:0, C16:0, C17:0, C18:0, C18:1 FAMEs, among which presence of C16:0 and C18:1 fatty acid indicated probable antimicrobial potentials of these strains.

SiC plasma characterization produced by 3 ns pulse laser at 1010 W/cm2 intensity

A silicon carbide (SiC) plasma has been produced by a Q-switched laser at 1064 nm, 3 ns pulse and 1010 W/cm2 intensity, in high vacuum to investigate the fundamental mechanisms of laser-semiconductor interaction. Although the high hardness and chemical stability restrain the SiC micromachining, it is a valuable semiconductor for devices working under extreme conditions. The plasma has been characterized by using time-of-flight (TOF) measurements of ions detected by an ion collector ring (ICR) and an ion energy analyzer (IEA). Fast CCD camera, quadrupole mass spectroscopy (QMS) and surface profiler have been employed to provide deep insights into the laser-SiC interaction mechanisms. Ion kinetic energies, charge states, plasma expansion velocity, ablation yield per laser pulse, plasma temperature and density have been measured. Applications of the laser-generated plasma are presented and discussed.

Phytochemical analysis, Thin Layer Chromatography and Gas Chromatography Mass Spectroscopy profile of colocasia esculenta and manihot esculanta extracts and their potential for drug discovery

Phytochemical analysis, Thin Layer Chromatography and Gas Chromatography Mass Spectroscopy profile of colocasia esculenta and manihot esculanta extracts and their potential for drug discovery

Structural Characterization, Spectroscopic Profile, Molecular Docking, ADMET Properties, Molecular Dynamics Simulation Studies, and Molecular Mechanics Generalized Born Surface Area Analysis of 5-(Adamantan-1-yl)-4-butyl-2,4-dihydro-3H-1,2,4-triazole-3-thione as a Potential COX Inhibitor.

Employing a synergistic combination of theoretical density functional theory (DFT) and experimental techniques, we conducted a comprehensive analysis elucidating the structural and pharmacological attributes of 5-(adamantan-1-yl)-4-butyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (5A4BT) as a potent COX inhibitor. The X-ray crystallographic data of 5A4BT showed the pivotal role played by weak interactions, notably π-π and C-H-π interactions, alongside hydrogen bonding, in orchestrating the intricate supramolecular architectures within the crystalline lattice. A quantitative analysis of the arrangement of the crystal structure, as well as both inter- and intramolecular interactions, was conducted using Hirshfeld surfaces and 2D fingerprint plots. Additionally, a comprehensive examination of the IR spectra was undertaken, employing both experimental methods and theoretical DFT techniques, to elucidate the vibrational characteristics of the compound. The strength of intermolecular N-H···S hydrogen bonding and charge transfer within the system was assessed through natural bonding orbital analysis. Moreover, Bader's atoms in molecules theory was employed to estimate the strength of intermolecular hydrogen bonds, revealing strong interactions within the 5A4BT dimer. The title compound exhibited binding affinities of -6.4 and -6.5 kcal/mol for COX1 (PDB 3KK6) and COX2 (1CX2) target proteins, respectively. For the first time, predictions regarding ADMET properties, drug-likeness, and toxicity, including favorable bioavailability, along with 100 ns molecular dynamics simulations, binding free energy, and energy decomposition per residue in the binding cavity of the protein from molecular mechanics generalized born surface area approach, collectively indicate the potential of 5A4BT as a nonselective COX inhibitor.

AI-Driven Spectral Decomposition: Predicting the Most Probable Protein Compositions from Surface Enhanced Raman Spectroscopy Spectra of Amino Acids.

Surface-enhanced Raman spectroscopy (SERS) is a powerful tool for elucidating the molecular makeup of materials. It possesses the unique characteristics of single-molecule sensitivity and extremely high specificity. However, the true potential of SERS, particularly in capturing the biochemical content of particles, remains underexplored. In this study, we harnessed transformer neural networks to interpret SERS spectra, aiming to discern the amino acid profiles within proteins. By training the network on the SERS profiles of 20 amino acids of human proteins, we explore the feasibility of predicting the predominant proteins within the µL-scale detection volume of SERS. Our results highlight a consistent alignment between the model's predictions and the protein's known amino acid compositions, deepening our understanding of the inherent information contained within SERS spectra. For instance, the model achieved low root mean square error (RMSE) scores and minimal deviation in the prediction of amino acid compositions for proteins such as Bovine Serum Albumin (BSA), ACE2 protein, and CD63 antigen. This novel methodology offers a robust avenue not only for protein analytics but also sets a precedent for the broader realm of spectral analyses across diverse material categories. It represents a solid step forward to establishing SERS-based proteomics.

Mass spectrometry and Nuclear magnetic resonance spectroscopy profiles of red and pink Rhododendron flower petals establish them as rich sources of bioactive secondary metabolites

AbstractRhododendron petals are considered high‐value owing to their commercial utility, national/state flower status in certain countries, and bioactive potential from recent studies. Profiling and quantitative analysis of the bioactive metabolites would evaluate if they can be natural sources. This study is focused on the comprehensive profiling of secondary metabolites in the hot aqueous petal extracts of Red and Pink Rhododendron flowers (Rhododendron arboreum and Rhododendron campanulatum) using separation and fragmentation patterns from mass spectrometry (MS) (gas chromatography‐MS and liquid chromatography‐tandem MS) and chemical shifts from proton‐nuclear magnetic resonance spectroscopy. The complementary analytical platforms highlighted the petals to be rich in promising bioactive molecules such as quinic acid, chlorogenic acid (caffeoyl quinic acid), protocatechuic acid, coumaroyl quinic acids, catechin, epigallocatechin, and shikimic acid. The analysis also reflected the activity of shikimic acid, phenolic acid, and flavonoid biosynthetic pathways in Rhododendron flowers. These metabolites are well reported for their bioactive potential as anti‐oxidative, anti‐viral, anti‐cancerous, anti‐diabetic, anti‐inflammatory, etc. While the quantitative and multivariate analysis showed variations in the levels of phenolic acids and flavonoids, it is established that red and pink Rhododendron flower petals are a rich source of bioactive phytochemicals of interest to the phytochemical Industry.

Production of novel mung bean peptides-based zinc supplement: Process optimization, chelation mechanism, and stability assessment in vitro

To realize the add value of protein resources from mung bean processing by-products, mung bean peptides-zinc chelate (MBP-Zn), a novel zinc supplement, was synthesized in the present study. Under the optimized process conditions (MBP concentration of 6%, pH 5.0, mass ratio of MBP to zinc salt of 2:1, temperature of 60 °C and time of 80 min), the zinc chelation rate of MBP-Zn reached up to 98.15%. Integrating the results of Fourier transform infrared spectroscopy and amino acid profiles, it is inferred that zinc ions may bind to MBP via carboxy oxygen, amino nitrogen, and sulfhydryl sulfur atoms. The incorporation of zinc ions dramatically changed the structure of the chelate, as evidenced by the blue shift and attenuation of the original UV and fluorescence spectra. The morphological analysis revealed that Zn2+ induced cross-linking of peptides, forming enlarged nanoparticles that fragmented the original smooth surface of MBP. Surprisingly, the superior stability of MBP-Zn over the conventional zinc supplement ZnSO4 was confirmed, regardless of pH and temperature variations, or simulated gastrointestinal digestion circumstances. These findings pave the way for the large-scale production of mung bean peptide-based zinc supplements as nutraceuticals in the food industry.