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Accurate diagnostic and serology assays are required for the continued management of the COVID-19 pandemic yet spike protein mutations and intellectual property concerns with antigens and antibodies used in various test kits render comparability assessments difficult. As the use of common, well-characterized reagents can help address this lack of standardization, the National Research Council Canada has produced two protein reference materials (RMs) for use in SARS-CoV-2 serology assays: biotinylated human angiotensin-converting enzyme 2 RM, ACE2-1, and SARS-CoV-2 Omicron BA.4/5 spike protein RM, OMIC-1. Reference values were assigned through a combination of amino acid analysis via isotope dilution liquid chromatography tandem mass spectrometry following acid hydrolysis, and ultraviolet–visible (UV–Vis) spectrophotometry at 280 nm. Vial-to-vial homogeneity was established using UV–Vis measurements, and protein oligomeric status, monitored by size exclusion liquid chromatography (LC-SEC), was used to evaluate transportation, storage, and freeze–thaw stabilities. The molar protein concentration in ACE2-1 was 25.3 ± 1.7 µmol L−1 (k = 2, 95% CI) and consisted almost exclusively (98%) of monomeric ACE2, while OMIC-1 contained 5.4 ± 0.5 µmol L−1 (k = 2) spike protein in a mostly (82%) trimeric form. Glycoprotein molar mass determination by LC-SEC with multi-angle light scattering detection facilitated calculation of corresponding mass concentrations. To confirm protein functionality, the binding of OMIC-1 to immobilized ACE2-1 was investigated with surface plasmon resonance and the resulting dissociation constant, KD ~ 4.4 nM, was consistent with literature values. [ABSTRACT FROM AUTHOR]

The hybrids (BY) derived from blunt snout bream (Megalobrama amblycephala, BSB, ♀) and Bleeker’s yellow tai (Xenocypris davidi Bleeker, YT, ♂) have a fast growth rate and body thickness. However, the molecular mechanisms underlying the growth advantage of BY are still unclear. MSTN, a member of the TGF-β superfamily, is a negative regulator of muscle growth and development. MYOD, a member of the myogenic regulatory factor family (MRFs), is a positive regulator of muscle growth and development. MSTN and MYOD interact to coregulate muscle growth and development. In this study, we cloned the full-length cDNAs of mstn and myod in BY, analyzed differential expression of the two genes in muscle of BY and its parents, and observed the localization of the two genes during embryonic development of BY. Multiple sequence alignment of amino acids and phylogenetic analysis showed that mstn and myod were highly conserved in BY, BSB, YT, and other carp family fishes. Quantitative Real-time PCR (qRT-PCR) showed that mstn and myod were primarily expressed in muscle of BY, and there were significant differences in the expression of the two genes in the red and white muscles of BY, BSB, and YT at different age. The results of in situ hybridization of embryos showed an overlap in the temporal and spatial expression of mstn and myod in BY embryo development, suggesting that the two genes might interact to co-regulate embryo growth and development. This study provides a theoretical basis for further research on the mechanisms of mstn and myod in muscle growth of hybrid fishes. [ABSTRACT FROM AUTHOR]

SUMMARY: Insects and their larvae have attracted attention as a sustainable alternative to traditional commodities in animal feeds. There are currently eight authorised insect species, where most of the research is taking place, the most prominent ones being the black soldier fly (Hermetia illucens) and the yellow mealworm (Tenebrio molitor). There are, however, many other alternatives, such as the superworm (Zophobas morio), which, although widely researched, have not yet been approved for use. This review provides a detailed examination of the chemical composition of these three insect species and their impact on broiler growth. Based on the analysis of recent scientific studies, it can be inferred that all three species demonstrate high protein content and a well-balanced composition of amino and fatty acids, along with substantial amounts of minerals, fibre and vitamins. Of particular note is their moderately low ash content, which enhances feed palatability, and the presence of essential minerals that can be further adjusted through substrate enrichment applications. All three species also present considerable amounts of vitamins and especially those of the vitamin B complex, enhancing various physiological functions. Should the challenges related to financial, risk and consumer acceptance factors be effectively managed, we can expect a swift advancement in the use of insects as feed ingredients in the very near future. [ABSTRACT FROM AUTHOR]

Rationale: Concerns exist over observed shifts in value and variance of nitrogen isotopes following physicochemical extraction of lipids from organic matter. The mechanisms behind these apparent changes in bulk tissue δ15N values are not fully understood yet have major implications for analytical costs and integrity of data interpretations. Methods: Changes in proximate analysis, amino acid composition, C:N ratios, bulk tissue and amino acid δ13C and δ15N values, and resulting isotope‐based food web metrics were compared between lipid‐intact and lipid‐extracted muscle tissue of fishes spanning <1% to >20% muscle fat content to identify mechanisms of nitrogen isotope fractionation associated with physicochemical lipid extraction. Results: Bulk δ13C and δ15N values increased and %N, C:N ratios and crude protein content decreased following lipid extraction. Resulting bulk isotope niche spacing and overlap varied significantly between lipid‐intact and lipid‐extracted tissues. While amino acid composition significantly changed during lipid extraction, particularly for lipid‐associated amino acids (e.g., Glu, Lys, Ser), individual amino acid δ13C and δ15N values, and their associated compound‐specific isotope analysis of amino acids (CSIA‐AA)‐based food web metrics, did not. Conclusions: Physicochemical lipid extraction caused significant tissue composition changes (e.g., leaching of amino acids and 15N‐deplete nitrogenous waste) that affected δ13C and δ15N values and tissue %C and %N beyond simply removing lipids. However, lipid extraction did not alter individual amino acid δ13C or δ15N values or their associated CSIA‐AA‐based food web metrics. [ABSTRACT FROM AUTHOR]

BACKGROUND: Peanut peptides have good chelating ability with metal ions. However, there are few studies on the chelation mechanism of peanut peptides with calcium and absorption properties of peptide–calcium complex. RESULTS: Peptides with high calcium chelating rate were isolated and purified from peanut protein hydrolysate (PPH), and the chelation rate of component F21 was higher (81.4 ± 0.8%). Six peptides were identified from component F21 by liquid chromatography–tandem mass spectrometry, and the frequency of acidic amino acids and arginine in the amino acid sequence was higher in all six peptides. Peanut peptide–calcium complex (PPH21‐Ca) was prepared by selecting component F21 (PPH21). Ultraviolet analysis indicated that the chelate reaction occurred between peanut peptide and calcium ions. Fourier transform infrared analysis showed that the chelating sites were carboxyl and amino groups on the amino acid residues of peptides. Scanning electron microscopy revealed that the surface of peanut peptide had a smooth block structure, but the surface of the complex had a granular morphology. Caco‐2 cell model tests revealed that the bioavailability of PPH21‐Ca was 58.4 ± 0.5%, which was significantly higher than that of inorganic calcium at 37.0 ± 0.4%. CONCLUSION: Peanut peptides can chelate calcium ions by carboxyl and amino groups, and the peptide–calcium complex had higher bioavailability. This study provides a theoretical basis for the development of new calcium supplement products that are absorbed easily. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Gelatinous filter feeders (e.g., salps, doliolids, and pyrosomes) have high filtration rates and can feed at predator:prey size ratios exceeding 10,000:1, yet are seldom included in ecosystem or climate models. We investigated foodweb and trophic dynamics in the presence and absence of salp blooms using traditional productivity and grazing measurements combined with compound-specific isotopic analysis of amino acids estimation of trophic position during Lagrangian framework experiments in the Southern Ocean. Trophic positions of salps ranging 10–132 mm in size were 2.2 ± 0.3 (mean ± std) compared to 2.6 ± 0.4 for smaller (mostly crustacean) mesozooplankton. The mostly herbivorous salp trophic position was maintained despite biomass dominance of ~10-µm-sized primary producers. We show that potential energy flux to >10-cm organisms increases by approximately an order of magnitude when salps are abundant, even without substantial alteration to primary production. Comparison to a wider dataset from other marine regions shows that alterations to herbivore communities are a better predictor of ecosystem transfer efficiency than primary-producer dynamics. These results suggest that diverse consumer communities and intraguild predation complicate climate change predictions (e.g., trophic amplification) based on linear food chains. These compensatory foodweb dynamics should be included in models that forecast marine ecosystem responses to warming and reduced nutrient supply. Food-web and isotope-based trophic analyses suggest that blooms of salps (gelatinous grazers) can increase ecosystem efficiency and energy transfer to large organisms. These compensatory food-web dynamics may offset predicted trophic amplification. [ABSTRACT FROM AUTHOR]

Gliomas, particularly glioblastomas (GBMs), pose significant challenges due to their aggressiveness and poor prognosis. Early detection through biomarkers is critical for improving outcomes. This study aimed to identify novel biomarkers for gliomas, particularly GBMs, using chiral amino acid profiling. We used chiral amino acid analysis to measure amino acid L- and D-isomer levels in resected tissues (tumor and non-tumor), blood, and urine from 33 patients with primary gliomas and 24 healthy volunteers. The levels of D-amino acid oxidase (DAO), a D-amino acid-degrading enzyme, were evaluated to investigate the D-amino acid metabolism in brain tissue. The GBM mouse model was created by transplanting GBM cells into the brain to confirm whether gliomas affect blood and urine chiral amino acid profiles. We also assessed whether D-amino acids produced by GBM cells are involved in cell proliferation. D-asparagine (D-Asn) levels were higher and DAO expression was lower in glioma than in non-glioma tissues. Blood and urinary D-Asn levels were lower in patients with GBM than in healthy volunteers (p < 0.001), increasing after GBM removal (p < 0.05). Urinary D-Asn levels differentiated between healthy volunteers and patients with GBM (area under the curve: 0.93, sensitivity: 0.88, specificity: 0.92). GBM mouse model validated the decrease of urinary D-Asn in GBM. GBM cells used D-Asn for cell proliferation. Gliomas induce alterations in chiral amino acid profiles, affecting blood and urine levels. Urinary D-Asn emerges as a promising diagnostic biomarker for gliomas, reflecting tumor presence and severity. [ABSTRACT FROM AUTHOR]

ABSTRACT Glucose abnormality is one of the atypical symptoms mostly overlooked during severe malaria. Screening for proteases involved in glucose abnormality suggests a potential new drug target. PF11_0189 is a putative insulin degrading enzyme found in the genome of Plasmodium falciparum. In silico approach revealed that PF11_0189 is similar to the metalloproteases exhibiting a zinc binding motif. The substrate binding region of PF11_0189 catalytic domain is lined by residues of a mixed nature, enabling the accommodation of both hydrophobic and hydrophilic residues from substrates. Analysis of each amino acid position from combinatorial peptide library suggests Thr and Ser to be the most crucial residues as upon its mutation significant improvement is observed in the binding. The peptides P‐21 (VPICSLY), P‐70 (TMICVLY), and P‐121 (AVICSLY) demonstrate significantly better interaction within the active site than a template peptide (TSICSLY). Molecular dynamic simulations confirm the complex's integrity, with all structures within the qualitative limit of compactness and stability during the simulation time. Principal component analysis (PCA) reveals major conformational motions and different energy landscapes, while dynamic cross‐correlation matrix (DCCM) highlights residue interactions of the complexes. The insights obtained through computational methods provide clues about substrate selectivity in PF11_0189, which can be utilized for peptide‐based therapeutics against severe malaria. [ABSTRACT FROM AUTHOR]

Chiral analysis is of high interest in many fields such as chemistry, pharmaceuticals and metabolomics. Mass spectrometry and ion mobility spectrometry are useful analytical tools, although they cannot be used as stand-alone methods. Here, we propose an efficient strategy for the enantiomer characterization of amino acids (AAs) using non-covalent copper complexes. A single ion mobility monitoring (SIM2) method was applied on a TIMS-ToF mass spectrometer to maximize the detection and mobility separation of isomers. Almost all of the 19 pairs of proteinogenic AA enantiomers could be separated with at least one combination with the chiral references L-Phe and L-Pro. Furthermore, we extended the targeted SIM2 method by stitching several mobility ranges, in order to be able to analyze complex mixtures in a single acquisition while maintaining high mobility resolution. Most of the enantiomeric pairs of AAs separated with the SIM2 method were also detected with this approach. The SIM2 stitching method thus opens the way to a more comprehensive chiral analysis with TIMS-ToF instruments. [ABSTRACT FROM AUTHOR]

Mianning ham is a traditional meat product in China. In this experiment, solid-phase microextraction–gas chromatography (SPME-GC-MS) and high-throughput sequencing were used to study the effects of adding Penicillium lanosum and adding the mixture of Penicillium lanosum and Staphylococcus equorum on the flavor and microbiology of Mianning ham. The results showed that the addition of the ferments resulted in an increase in the abundance of both the dominant bacterial phylum (Thick-walled Bacteria) and the dominant fungal phylum (Ascomycota). The variety of volatile flavor substances and key flavor substances increased after adding fermentation agents. A free amino acid analysis showed that hams from the Penicillium lanosum and Staphylococcus equorum group had significantly higher umami flavor amino acids than the control group and Penicillium lanosum group. Therefore, inoculation with Penicillium lanosum and Staphylococcus equorum favored the dominant bacteria and flavor of Mianning ham. [ABSTRACT FROM AUTHOR]

L-Phenylalanine (L-Phe), which is one of the essential amino acids, is important for the human body because it is used in the biosynthesis of neurotransmitters. Phenylalanine dehydrogenase (PheDH) has been studied as a material for the L-Phe sensor. In particular, the accurate and simple determination of L-Phe concentrations in human samples is needed for the diagnosis and treatment of patients with phenylketonuria. Thermostable PheDH from the bacterium Thermoactinomyces intermedius is suitable as a sensor material; however, it is reactive to not only L-Phe but also L-tyrosine (L-Tyr). Thus, we attempted to improve its substrate specificity for the accurate measurement of L-Phe. In this study, we developed the PheDH mutant with improved substrate specificity by amino acid substitution. The PheDH mutant, in which the 290th asparagine residue was substituted with aspartic acid (N290D), is considered to form a new interaction in the substrate binding site and has a markedly reduced reactivity with L-Tyr compared with the wild-type PheDH; the relative activities (L-Tyr/L-Phe) of the wild-type PheDH and the PheDH N290D mutant were 64.0 and 1.5%, respectively. An enzymatic assay using this mutant was established to quantify the L-Phe concentration in human plasma. The relative errors ranged from −10.3 to 7.4% when compared with the quantitative value determined by high-performance liquid chromatography/electrospray ionization mass spectrometry. Furthermore, the immobilized mutant showed a concentration-dependent reactivity with L-Phe and no reactivity with L-Tyr, which indicate its potential use as a sensor material. [ABSTRACT FROM AUTHOR]

l-glutamate is an umami component found in various foods, and l-glutamate oxidase (LGOX, EC 1.4.3.11) is a FAD-dependent oxidoreductase that catalyzes the oxidative deamination of l-glutamate. A recently reported single-chain LGOX mutant from Streptomyces sp. X-119-6 is a potential material for l-glutamate sensors because this mutant is easier to prepare than the wild type. Herein, we report the development of a simple analytical kit using this LGOX mutant for the on-site quantification of l-glutamate. The kit named PACKTEST was developed using a colorimetric method to estimate the l-glutamate concentration in the range of 1–50 mg/L through the visual comparison of the resulting sample color with a standard color sequence. In addition, the PACKTEST kit was combined with a portable photometer for the spectrophotometric quantification of l-glutamate in the range of 0.5–12.0 mg/L. It was used to quantify l-glutamate in commercially available soy sauces, and the results were in good agreement (r = 0.97) with the values obtained by post-column derivatized ion-exchange chromatography. Furthermore, we loaded and dried all the reagents, including enzymes, on a 96- well plate to prepare an enzyme-based sensing device, which showed potential for the high-throughput quantification of l-glutamate. [ABSTRACT FROM AUTHOR]

Objective Adrenal cortisol production occurs through a biosynthetic pathway which depend on NADH and NADPH for energy supply. The mitochondrial respiratory chain and the reactive oxygen species (ROS) detoxification system are therefore important for steroidogenesis. Mitochondrial dysfunction leading to oxidative stress has been implicated in the pathogenesis of several adrenal conditions. Nonetheless, only very few patients with variants in one gene of the ROS detoxification system, Thioredoxin Reductase 2 (TXNRD2), have been described with variable phenotypes. Design Clinical, genetic, structural, and functional characterization of a novel, biallelic TXNRD2 splice variant. Methods On human biomaterial, we performed whole exome sequencing to identify and RNA analysis to characterize the specific TXNRD2 splice variant. Amino acid conservation analysis and protein structure modeling were performed in silico. Using patient's fibroblast-derived human induced pluripotent stem cells, we generated adrenal-like cells (iALC) to study the impact of wild-type (WT) and mutant TXNRD2 on adrenal steroidogenesis and ROS production. Results The patient had a complex phenotype of primary adrenal insufficiency (PAI), combined with genital, ophthalmological, and neurological features. He carried a homozygous splice variant c.1348-1G > T in TXNRD2 which leads to a shorter protein lacking the C-terminus and thereby affecting homodimerization and flavin adenine dinucleotide binding. Patient-derived iALC showed a loss of cortisol production with overall diminished adrenal steroidogenesis, while ROS production was significantly increased. Conclusion Lack of TXNRD2 activity for mitochondrial ROS detoxification affects adrenal steroidogenesis and predominantly cortisol production. [ABSTRACT FROM AUTHOR]

Objective: Our primary objective was to investigate the variability of oxytocin (OT) and the GAMEN binding motif within the LNPEP oxytocinase in primates. Materials and Methods: We sequenced the LNPEP segment encompassing the GAMEN motif in 34 Platyrrhini species, with 21 of them also sequenced for the OT gene. Our dataset was supplemented with primate sequences of LNPEP, OT, and the oxytocin receptor (OTR) sourced from public databases. Evolutionary analysis and coevolution predictions were made followed by the macroevolution analysis of relevant amino acids associated with phenotypic traits, such as mating systems, parental care, and litter size. To account for phylogenetic structure, we utilized two distinct statistical tests. Additionally, we calculated binding energies focusing on the interaction between Callithtrix jacchus VAMEN and Pro8OT. Results: We identified two novel motifs (AAMEN and VAMEN), challenging the current knowledge of motif conservation in placental mammals. Coevolution analysis demonstrated a correlation between GAMEN, AAMEN, and VAMEN and their corresponding OTs and OTRs. Callithrix jacchus exhibited a higher binding energy between VAMEN and Pro8OT than orthologous molecules found in humans (GAMEN and Leu8OT). Discussion: The coevolution of AAMEN and VAMEN with their corresponding OTs and OTRs suggests a functional relationship that could have contributed to specific reproductive and adaptive behaviors, including paternal care, social monogamy, and twin births, prominent traits in Cebidae species, such as marmosets and tamarins. Our findings underscore the coevolution of taxon‐specific amino acids among the three studied molecules, shedding light on the oxytocinergic system as an adaptive epistatic repertoire in primates. [ABSTRACT FROM AUTHOR]

The study was conducted exploit the proteins of the pods of some types of plants, such as Prosopis juliflora pods, that are considered by -products in many countries and considered a good source of protein in the preparation of protein hydrolysers and evaluating their effect on inhibiting brown discoloration of apple slices and compared with anti -browning agents (ascorbic acid, acetic acid, and sodium chloride) when stored in the refrigerator for 0, 5 and 8 days. The chemical composition of the moisture, protein, fat, ash, and carbohydrate of the P. juliflora pods was estimated, then the hydrolysis process was carried out using the enzymes trypsin and papain for 300 minutes. Amino acids and FTIR analysis of protein hydrolysates were determined. Significant changes (p≤0.05) in pH, total soluble solids, and non - significant changes in titration acidity of apple slices treated with protein hydrolysis and anti -browning agents were studied and significantly decreased (p≤0.05) in the activity of polyphenol oxidase until the end of the storage. The brown coloration decreased when treated with protein hydrolysates compared to other treatments, but non -significant changes. As a result, apple slices can be preserved with protein hydrolysers for several days in the refrigerator. [ABSTRACT FROM AUTHOR]

Killer whales (Orcinus orca) occur seasonally in the eastern Canadian Arctic (ECA), where their range expansion associated with declining sea ice have raised questions about the impacts of increasing killer whale predation pressure on Arctic‐endemic prey.We assessed diet and distribution of ECA killer whales using bulk and compound‐specific stable isotope analysis (CSIA) of amino acids (AA) of 54 skin biopsies collected from 2009 to 2020 around Baffin Island, Canada.Bulk ECA killer whale skin δ15N and δ13C values did not overlap with potential Arctic prey after adjustment for trophic discrimination, and instead reflected foraging history in the North Atlantic prior to their arrival in the ECA. Adjusted killer whale stable isotope (SI) values primarily overlapped with several species of North Atlantic baleen whales or tuna. Amino acid (AA)‐specific δ15N values indicated the ECA killer whales fed primarily on marine mammals, having similar glutamic acid δ15N–phenylalanine δ15N (δ15NGlx‐Phe) and threonine δ15N (δ15NThr) as mammal‐eating killer whales from the eastern North Pacific (ENP) that served as a comparative framework. However, one ECA whale grouped with the fish‐eating ENP ecotype based δ15NThr.Distinctive essential AA δ13C of ECA killer whale groups, along with bulk SI similarity to killer whales from different regions of the North Atlantic, indicates different populations converge in Arctic waters from a broad source area. Generalist diet and long‐distance dispersal capacity favour range expansions, and integration of these insights will be critical for assessing ecological impacts of increasing killer whale predation pressure on Arctic‐endemic species. [ABSTRACT FROM AUTHOR]

We hypothesized that removing water from fish muscle homogenate by freeze‐drying might be a cost‐effective way to stabilize nutrients and allow higher temperatures for long‐term frozen storage prior to analytical measurements. To test our hypothesis, fish muscle fillets from lipid‐rich farmed Atlantic salmon (n = 5) and lean wild‐caught European plaice (n = 5) were homogenized and fresh‐frozen at −20 and −80°C. A subset of these samples was freeze‐dried prior to further frozen storage at the respective temperatures. Using validated methods, vitamins, amino acids, and fatty acids were measured after a short time of storage (starting point) and up to 1 year (endpoint), with intermediate analytical checkpoints of 1, 3, and 6 months. Trends in the degradation of certain nutrients during the different frozen storage conditions are discussed. In general, by freeze‐drying fish homogenate samples prior to frozen storage at −20°C for up to 1 year, amino acids, vitamins, and fatty acids were stabilized in both salmon and plaice when compared to wet‐frozen storage of the same samples, and storage at −80°C did not improve preservation of the freeze‐dried samples. For wet‐frozen samples, −80°C would be recommended for 1‐year storage of fillet homogenate samples, even though several nutrients preserved well at −20°C. Practical Application: We present individual nutrient stability profiles in muscle homogenates from fatty fish (salmon) and lean fish (plaice) during different frozen storage conditions over time. Based on these data, freeze‐drying followed by frozen storage at −20°C for at least 1 year could be applied prior to analyses of amino acids, fat‐soluble vitamins, water‐soluble vitamins, and fatty acids. Of note is that freeze‐drying followed by frozen storage before analysis led to slightly increased measurements of several fatty acids in plaice samples, possibly attributable to an increase in dry weight or an enhancement in extraction efficiency through freeze‐drying. [ABSTRACT FROM AUTHOR]

Nested within the vast genetic landscape of the major histocompatibility complex (MHC), a cluster of genes assumes a pivotal role in pathogen recognition and orchestrating mechanisms for disease resistance. This investigation successfully cloned and sequenced the complete 786 bp cDNA entity corresponding to the MHC-DQB gene in yaks. A comprehensive analysis of the sequence unveiled distinct features, including highly conserved peptide binding sites (PBS) spanning 8 amino acids and specific nucleotide-binding regions at designated positions (–1, –28, 2, 3, 29, 64, 93, and 108). The pronounced uniformity and remarkable preservation demonstrated by the yak MHC-DQB gene underscore its potential in providing protection against pathogens and the inherent stability within the DQB genetic framework. Moreover, a comparison across six distinct domains of the Yak-DQB gene revealed notable similarities with closely related species. Particularly significant is the identification of a conserved peptide-binding region consisting of 16 amino acids, alongside the detection of multiple conserved nucleotide-binding regions. When conducting a comparative analysis of amino acid lengths in the Yak-DQB orthologous sequence, a substantial homology with cattle was observed, registering at 91.2%. Interestingly, however, the DQB gene in yaks exhibited discrepancies in 23 amino acids compared to the bovine sequence. Specifically, a detailed examination revealed that 15 of these variable amino acids were clustered within the Beta 1 (в1) domain. These insights provide valuable information about the distinct characteristics of the MHC gene in both ruminant and non-ruminant species, unraveling the complexities of their comparative molecular genetics. [ABSTRACT FROM AUTHOR]

The article presents the discussion on impact of rising marine feed costs on aquaculture, highlighting the shift towards plant and animal byproducts in fish diets due to the scarcity of fishmeal and fish oil. Topics include the role of plant-derived feedstuffs in aquaculture, the importance of amino acids for fish health; and the challenges of balancing amino acid profiles in fish diets to ensure nutritional adequacy.

Calcium-binding peptides have gained significant attention due to their potential applications in various fields. In this study, we aimed to prepare, characterize, and evaluate the stability of calcium-binding peptides derived from chicken blood. Chicken hemoglobin peptides (CPs) were obtained by protease hydrolysis and were applied to prepare chicken hemoglobin peptide–calcium chelate (CP-Ca). The preparation conditions were optimized, and the characteristics and stability of CP-Ca were analyzed. The optimal chelating conditions were determined by single-factor and response surface tests, and the maximum calcium ion chelating rate was 77.54%. Amino acid analysis indicated that glutamic acid and aspartic acid motifs played an important role in the chelation of the calcium ions and CP. According to the characterization analysis, CP-Ca was a different substance compared with CP; calcium ions chelated CPs via the sites of carbonyl oxygen, carboxyl oxygen, and amino nitrogen groups; and after the chelation, the structure changed from a smooth homogeneous plate to compact granular. The stability analysis showed that CP-Ca was stable at different temperatures, pH, and gastrointestinal conditions. The study indicates that chicken blood is a promising source of peptide–calcium chelates, providing a theoretical basis for application in functional foods and improving the utilization value of chicken blood. [ABSTRACT FROM AUTHOR]

The aim of this research is to propose simple and scalable processes to obtain bioactive peptides extensively hydrolyzed starting from a tuna mixed biomass. The upcycling of this powdered biomass is challenging since it comes from the unsorted industrial side streams of the tuna canning process (cooked residues from fillet trimming) after a patented mild dehydration useful for preventing its degradation until its exploitation. Two different protocols were proposed, with and without the inclusion of an exogenous enzyme (Enzymatic-Assisted Extraction, EAE), with no relevant differences in yields (24% vs. 22%) and a comparable amino acid composition. Nevertheless, the former protocol (with EAE) provided peptides with an average molecular weight of 1.3 kDa, and the second one (without EAE) provided peptides with an average molecular weight of 2.2 kDa. The two corresponding types of tuna protein hydrolysates (Enzymatic Hydrolysates (EH) and Non-Enzymatic Hydrolysates (NEH)) were characterized by proximate compositions, pH, color profile, amino acid analysis, FTIR spectra, and molecular weight distribution. In addition, several biological analyses were performed to assess their potential use as nutraceutical supplements: special attention has been paid to antioxidant activity using three different methods to quantify it. EH showed the most promising antioxidant activity which could be exploited also in other fields (e.g., biomaterials, cosmetics). [ABSTRACT FROM AUTHOR]

Soybean, a primary vegetable protein source, boasts favorable amino acid profiles; however, its composition still falls short of meeting human nutritional demands. The soybean amino acid content is a quantitative trait controlled by multiple genes. In this study, an F2 population of 186 individual plants derived from the cross between ChangJiangChun2 and JiYu166 served as the mapping population. Based on the previously published genetic map of our lab, we increased the density of the genetic map and constructed a new genetic map containing 518 SSR (simple sequence repeats) markers and 64 InDel (insertion-deletion) markers, with an average distance of 5.27 cm and a total length of 2881.2 cm. The content of eight essential amino acids was evaluated in the F2:5, F2:6, and BLUP (best linear unbiased prediction). A total of 52 QTLs (quantitative trait loci) were identified, and 13 QTL clusters were identified, among which loci02.1 and loci11.1 emerged as stable QTL clusters, exploring candidate genes within these regions. Through GO enrichment and gene annotation, 16 candidate genes associated with soybean essential amino acid content were predicted. This study would lay the foundation for elucidating the regulatory mechanisms of essential amino acid content and contribute to germplasm innovation in soybeans. [ABSTRACT FROM AUTHOR]

Hydrogels have the ability to retain large amounts of water within their three-dimensional polymer matrices. These attractive materials are used in medicine and the food industry; they can serve as the basis for structured food products, additives, and various ingredients. Gelatin is one of widely used biopolymers to create hydrogels that exhibit biocompatibility and tunable rheological properties. In this study, we offer a comparative analysis of rheological properties of gelatin-based hydrogels (C = 6.67%), including mammalian gelatins from bovine and porcine skins and fish gelatins from commercial samples and samples extracted from Atlantic cod skin. Mammalian gelatins provide high strength and elasticity to hydrogels. Their melting point lies in the range from 22 to 34 °C. Fish gelatin from cod skin also provides a high strength to hydrogels. Commercial fish gelatin forms weak gels exhibiting low viscoelastic properties and strength, as well as low thermal stability with a melting point of 7 °C. Gelatins were characterized basing on the analysis of amino acid composition, molecular weight distribution, and biopolymer secondary structure in gels. Our research provides a unique rheological comparison of mammalian and fish gelatin hydrogels as a tool for the re-evaluation of fish skin gelatin produced through circular processes. [ABSTRACT FROM AUTHOR]

Nitrogen isotope analyses of amino acids (δ15N‐AA) are being increasingly used to decipher trophic dynamics. Interpretation of δ15N‐AA in consumers relies on the assumption that consumer physiological status and nutritional status of prey have negligible influences on the trophic discrimination factor (TDF), hence a constant TDF value is used in trophic position (TP) equations. Recent experiments have shown that this is not always the case and there is also a need to validate derived TP estimates in the field. We take advantage of the uniquely long time series of environmental monitoring data and archived (frozen) samples from the species‐poor Baltic Sea. We analyzed δ15N‐AA in similar sized individuals of cod and in its prey herring from four decades, 1980–2018; including time periods where dramatic reduction in condition status of cod has occurred. We expected that TDF in trophic AAs would increase during periods of poor cod condition, resulting in inflated TP estimates. We found that calculated TP and empirical estimates of TDF (difference in δ15N in trophic AAs between cod and herring) for cod increased in recent decades and that this was linked to condition status, herring (prey) lipid content and the hypoxic state of the ecosystem. Statistically adjusting TP for condition and prey lipid content as well as environmental stress (hypoxia) resulted in lower cod TP which better resembled the observed decrease in herring TP in recent decades. TP calculated from stomach analysis data in cod individuals over the same period showed no trend over time and confirmed that adjusted TP estimates mirror the real dietary TP better than unadjusted. By simultaneously measuring condition/nutritional status in both predator and prey it is possible to adjust for them as confounding variables and decipher actual consumer TP, partly overcoming the issues of unknown and variable TDF‐values. Our study also highlights the importance of including environmental stressors (here hypoxia) when interpreting TP and reconstructing food webs. [ABSTRACT FROM AUTHOR]

This study focuses on the potential of addition of flaxseed, soybean, sunflower, peanut, and pumpkin cakes in gluten-free flour formulations, using rice flour, corn flour, and corn starch. The aim of the article is to investigate the impact of oil cake flour incorporation on the structure and mineral composition of gluten-free mixtures. The control sample (without cake flour) and four experimental samples were prepared. To obtain a gluten-free mixture, the ingredients were dosed and mixed in dry form, namely 50% finely ground white rice, 30% corn starch, 10% corn flour, and 10% oil cake flour. The investigation reveals distinct nutritional profiles, with significant variations in protein, fat, carbohydrate, and calorie content among the different types of cakes. Amino acid composition analysis showcased variations among oil cakes, emphasizing their potential as diverse protein sources. Fatty acid composition revealed caproic acid as the predominant fatty acid. Peanut cake displayed the highest omega-3 content (0.21%), emphasizing its potential health benefits. Pumpkin cake stood out with the highest magnesium (472.63 mg/100 g) and phosphorus (893.69 mg/100 g) content. Flaxseed cake led in calcium (225.92 mg/100 g), while soybean cake excelled in potassium (2549.0 mg/100 g), iron (9.13 mg/100 g), and copper (2.03 mg/100 g) content. X-ray fluorescence and phase analysis confirmed the amorphous nature of gluten-free mixtures with oilseed meal. Electron microscopy results showed that the gluten-free mixtures with cake addition consisted of particles ranging in size from 2.5 to 25 microns. Overall, incorporating oilseed meal flour into gluten-free formulations enhances nutritional value without compromising structural properties, making it a promising ingredient in food production. [ABSTRACT FROM AUTHOR]

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The genus Staphylococcus encompasses a diverse array of bacteria with significant implications for human health, including disreputable pathogens such as Staphylococcus aureus and Staphylococcus epidermidis. Understanding the genetic composition and codon usage patterns of Staphylococcus species is crucial for unraveling their evolutionary dynamics, adaptive strategies, and pathogenic potential. In this study, we conducted a comprehensive analysis of codon usage patterns across 48 species within the Staphylococcus genus. Our findings uncovered variations in genomic G-C content across Staphylococcus species, impacting codon usage preferences, with a notable preference for A/T-rich codons observed in pathogenic strains. This preference for A/T-rich codons suggests an energy-saving strategy in pathogenic organisms. Analysis of dinucleotide pair expression patterns unveiled insights into genomic dynamics, with overrepresented codon pairs reflecting trends in dinucleotide expression across genomes. Additionally, a significant correlation between CAI and genomic G-C content underscored the intricate relationship between codon usage patterns and gene expression strategies. Amino acid usage analysis highlighted preferences for energetically cheaper amino acids, suggesting adaptive strategies promoting energy efficiency. This comprehensive analysis sheds light on the evolutionary dynamics and adaptive mechanisms employed by Staphylococcus species, providing valuable insights into their pathogenic potential and clinical implications. Understanding these genomic features is crucial for devising strategies to combat staphylococcal infections and improve public health outcomes. [ABSTRACT FROM AUTHOR]

Background Results Conclusion Peanut peptides can chelate iron but their chelation mechanism remains unclear. The purpose of this study is to separate peanut ferrous‐chelating peptides and explore the chelation mechanism of peanut peptides with iron.Peanut peptide component F‐122, which had a higher chelation rate, was separated using ultrafiltration, gel filtration chromatography, and ion exchange chromatography, achieving a ferrous chelation rate of 90.7%. Six peptide segments were screened and their amino acid sequences were identified by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Spectral analysis confirmed that the chelation between peanut peptides and ferrous ions occurred and a new substance was formed. Molecular docking simulation indicated that the amino acids in peanut peptides involved in the chelating reaction were glutamic acid, arginine, glycine, threonine, phenylalanine, and lysine. The binding sites included the main chain oxygen atom, side chain oxygen atom, and carboxyl oxygen atom of amino acid.The isolated peanut peptide had a higher ferrous‐chelation rate. The chelating mechanism of peanut peptide with ferrous ion was elucidated. This study provides a theoretical basis for the development of new peptide‐ferrous preparations. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The macrocyclic tumonolide (1) with enamide functionality and the linear tumonolide aldehyde (2) are new interconverting natural products from a marine cyanobacterium with a peptide‐polyketide skeleton, representing a hybrid of apratoxins and palmyrolides or laingolides. The planar structures were established by NMR and mass spectrometry. The relative configuration of the stereogenically‐rich apratoxin‐like polyketide portion was determined using J‐based configuration analysis. The absolute configuration of tumonolide (1) was determined by chiral analysis of the amino acid units and computational methods, followed by NMR chemical shift and ECD spectrum prediction, indicating all‐R configuration for the polyketide portion, as in palmyrolide A and contrary to the all‐S configuration in apratoxins. Functional screening against a panel of 168 GPCR targets revealed tumonolide (1) as a selective antagonist of TACR2 with an IC50 of 7.0 μM, closely correlating with binding affinity. Molecular docking studies established the binding mode and rationalized the selectivity for TACR2 over TACR1 and TACR3. RNA sequencing upon treatment of HCT116 colorectal cancer cells demonstrated activation of the pulmonary fibrosis idiopathic signaling pathway and the insulin secretion signaling pathway at 20 μM, indicating its potential to modulate these pathways. [ABSTRACT FROM AUTHOR]

Primary glomerular disease (PGD) is an idiopathic cause of renal glomerular lesions that is characterized by proteinuria or hematuria and is the leading cause of chronic kidney disease (CKD). The identification of circulating biomarkers for the diagnosis of PGD requires a thorough understanding of the metabolic defects involved. In this study, ultra-high performance liquid chromatography–tandem mass spectrometry was performed to characterize the amino acid (AA) profiles of patients with pathologically diagnosed PGD, including minimal change disease (MCD), focal segmental glomerular sclerosis (FSGS), membranous nephropathy, and immunoglobulin A nephropathy. The plasma concentrations of asparagine and ornithine were low, and that of aspartic acid was high, in patients with all the pathologic types of PGD, compared to healthy controls. Two distinct diagnostic models were generated using the differential plasma AA profiles using logistic regression and receiver operating characteristic analyses, with areas under the curves of 1.000 and accuracies up to 100.0% in patients with MCD and FSGS. In conclusion, the progression of PGD is associated with alterations in AA profiles, The present findings provide a theoretical basis for the use of AAs as a non-invasive, real-time, rapid, and simple biomarker for the diagnosis of various pathologic types of PGD. [ABSTRACT FROM AUTHOR]

Avian metapneumovirus (aMPV) poses a significant threat to the poultry industry worldwide, primarily affecting turkeys and chickens. The recent detection of aMPV-A and -B subtypes in the United States marks a significant shift after a prolonged period free of aMPV following the eradication of the previously circulating subtype C. Hence, the demand for molecular diagnostic tests for aMPV has arisen due to their limited availability in the US market. In this study, we present the molecular characterization based on the complete genome sequence of aMPV subtype A, which was detected in the US for the first time. Four RT-qPCR positive samples were subjected to next-generation sequencing analysis, resulting in the assembly of one complete and one near-complete genome sequences. Phylogenetic analysis revealed that the isolated strains clustered within the aMPV-A subtype and were most closely related to recent Mexican strains. A detailed amino acid analysis identified unique mutations in the G gene of the US isolates compared to Mexican strains. Additionally, we compared the performance, cross-reactivity, and limit of detection of our revised aMPV subtype-specific RT-qPCR test with two commercial kits, demonstrating similar detection and subtyping capabilities. These findings highlight the importance of accurate diagnostic methods for disease management in the poultry industry, provide valuable insights into the epidemiology of aMPV, and underscore the need for continued vigilance and surveillance to mitigate its impact on poultry production. [ABSTRACT FROM AUTHOR]

Gelatin is a product obtained through partial hydrolysis and thermal denaturation of collagen, belonging to natural biopeptides. With irreplaceable biological functions in the field of biomedical science and tissue engineering, it has been widely applied. The amino acid sequence of recombinant human-like gelatin was constructed through a newly designed hexamer composed of six protein monomer sequences in series, with the minimum repeating unit being the characteristic Gly-X-Y sequence found in type III human collagen α1 chain. The nucleotide sequence was subsequently inserted into the genome of Pichia pastoris to enable soluble secretion expression of recombinant gelatin. At the shake flask fermentation level, the yield of recombinant gelatin is up to 0.057 g/L, and its purity can rise up to 95% through affinity purification. It was confirmed in the molecular weight determination and amino acid analysis that the amino acid composition of the obtained recombinant gelatin is identical to that of the theoretically designed. Furthermore, scanning electron microscopy revealed that the freeze-dried recombinant gelatin hydrogel exhibited a porous structure. After culturing cells continuously within these gelatin microspheres for two days followed by fluorescence staining and observation through confocal laser scanning microscopy, it was observed that cells clustered together within the gelatin matrix, exhibiting three-dimensional growth characteristics while maintaining good viability. This research presents promising prospects for developing recombinant gelatin as a biomedical material. [ABSTRACT FROM AUTHOR]

Background: Multiple sclerosis (MS) and myasthenia gravis (MG) are autoimmune diseases that attack the central nervous system (CNS) and the neuromuscular junction, respectively. As the common pathogenesis of both diseases is associated with an autoimmune background and the involvement of T and B lymphocytes, the overlapping of selected clinical symptoms may cause difficulties in the differential diagnosis of both diseases. Methods: The aim of the study was to use Liquid Chromatography–Electrospray Ionization–Mass Spectrometry (LC–ESI–MS/MS) in conjunction with multivariate statistical analyses to examine the changes in amino acid metabolic profiles between patients with MG, MS, and a control group. Results: Comparative analysis of amino acids (AA) between patients with MG, MS, and within the control group allowed for the identification of statistically significant differences in the amino acid profile. Comparing the patients (patients with MS and MG) with the control group, and after taking the results of multiple tests into account, it was observed that amino acids such as ARG, PRO, TRP, CIT were significantly different between the groups. When considering the comparison between the AA concentrations in MS and MG patients, we found three AAs that were significantly different in the MS and MG groups, after correcting for multiple testing (CIT, GABA, and AAA). Higher concentrations of amino acids that showed significant differences were observed in patients with myasthenia gravis. Conclusions: Our results have indicated AAs that may prove valuable for improving the diagnostics of MS and MG patients. To better assess the potential utility of these markers, their performance requires further validation in a larger study group and limitation of possible confounding factors, e.g., medications and diet. [ABSTRACT FROM AUTHOR]

Chlorella sorokiniana, isolated from a pond adjacent to a cement plant, was cultured using flue gas collected directly from kiln emissions using 20 L and 25000 L photobioreactors. Lipids, proteins, and polysaccharides were analyzed to understand their overall composition for potential applications. The lipid content ranged from 17.97% to 21.54% of the dry biomass, with carotenoid concentrations between 8.4 and 9.2 mg/g. Lutein accounted for 55% of the total carotenoids. LC/MS analysis led to the identification of 71 intact triacylglycerols, 8 lysophosphatidylcholines, 10 phosphatidylcholines, 9 monogalactosyldiacylglycerols, 12 digalactosyldiacylglycerols, and 1 sulfoquinovosyl diacylglycerol. Palmitic acid, oleic acid, linoleic acid, and α-linolenic acid were the main fatty acids. Polyunsaturated fatty acid covers ≥ 56% of total fatty acids. Protein isolates and polysaccharides were also extracted. Protein purity was determined to be ≥75% by amino acid analysis, with all essential amino acids present. Monomer analysis of polysaccharides suggested that they are composed of mainly D-(+)-mannose, D-(+)-galactose, and D-(+)-glucose. The results demonstrate that there is no adverse effect on the metabolite profile of C. sorokiniana biomass cultured using flue gas as the primary carbon source, revealing the possibility of utilizing such algal biomass in industrial applications such as animal feed, sources of cosmeceuticals, and as biofuel. [ABSTRACT FROM AUTHOR]

In recent years, the avian influenza virus has emerged as a significant threat to both human and public health. This study focuses on a patient infected with the H10N3 subtype of avian influenza virus, admitted to the Third People's Hospital of Kunming City on March 6, 2024. Metagenomic RNA sequencing and polymerase chain reaction (PCR) analysis were conducted on the patient's sputum, confirming the H10N3 infection. The patient presented severe pneumonia symptoms such as fever, expectoration, chest tightness, shortness of breath, and cough. Phylogenetic analysis of the Haemagglutinin (HA) and neuraminidase (NA) genes of the virus showed that the virus was most closely related to a case of human infection with the H10N3 subtype of avian influenza virus found in Zhejiang Province, China. Analysis of amino acid mutation sites identified four mutations potentially hazardous to human health. Consequently, this underscores the importance of continuous and vigilant monitoring of the dynamics surrounding the H10N3 subtype of avian influenza virus, utilizing advanced genomic surveillance techniques. [ABSTRACT FROM AUTHOR]

Background: Although milk is nutritionally valuable, it also serves as a significant medium for the transmission of pathogens and their toxins. Aim: This study aimed to investigate the role of enterotoxin gene A (SEA) in the development of bovine mastitis. We accomplished this by examining milk through polymerase chain reaction (PCR) testing, amino acid substitution analysis, and phylogenetic analysis. Methods: A total of fifty milk samples were collected from locally bred dairy cows in Al-Diwaniyah, located in southern Iraq. We employed the VITEK-2 platform to validate the diagnosis of Staphylococcus aureus and confirm the results of routine tests (culturing and biochemical tests). Subsequently, the genetic mutation and phylogeny analysis were achieved utilizing DNA sequencing to 16S rRNA and enterotoxin A genes. Results: 66% (33/50) of the milk samples found to be contain S. aureus by the VITEK-2 system. Furthermore, 25/33 of the samples were positive by the PCR test. While 60% (15 out of 25) tested positive for the SEA gene. After genomic analysis, we identified amino acid substitutions of serine, glutamine with arginine, tyrosine with cysteine, and aspartic acid with glycine at positions 9, 101, 119, 187, and 191. The phylogenetic investigation demonstrated a genetic relationship between our isolates (Iraqi isolates) and isolates from Indian and the United States. Conclusion: Our study indicated the widespread distribution of the enterotoxin gene A (SEA) of S. aureus among dairy cows. The molecular study revealed significant changes in key amino acids that could play an important role in the bacterium's pathogenesis. The phylogenetic similarities among S. aureus samples from various countries suggest that the bacteria has spread globally. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is an increasingly important public health concern due to the increasing proportion of older individuals within the general population. The impairment of processes responsible for adequate brain energy supply primarily determines the early features of the aging process. Restricting brain energy supply results in brain hypometabolism prior to clinical symptoms and is anatomically and functionally associated with cognitive impairment. The present study investigated changes in metabolic profiles induced by intracerebroventricular‐streptozotocin (ICV‐STZ) in an AD‐like animal model. To this end, male Wistar rats received a single injection of STZ (3 mg·kg−1) by ICV (2.5 μL into each ventricle for 5 min on each side). In the second week after receiving ICV‐STZ, rats were tested for cognitive performance using the Morris Water Maze test and subsequently prepared for positron emission tomography (PET) to confirm AD‐like symptoms. Tandem Mass Spectrometry (MS/MS) analysis was used to detect amino acid changes in cerebrospinal fluid (CFS) samples. Our metabolomics study revealed a reduction in the concentrations of various amino acids (alanine, arginine, aspartic acid, glutamic acid, glycine, isoleucine, methionine, phenylalanine, proline, serine, threonine, tryptophane, tyrosine, and valine) in CSF of ICV‐STZ‐treated animals as compared to controls rats. The results of the current study indicate amino acid levels could potentially be considered targets of nutritional and/or pharmacological interventions to interfere with AD progression. [ABSTRACT FROM AUTHOR]

Emerging non-thermal technologies are widely applied in storage and processing of aquatic products, especially ultrasound-assisted technology. Frequency is an important component of ultrasound, and the effects of different ultrasound frequencies are obviously different. This research evaluated the effects of single-frequency (28 kHz, 40 kHz) and dual-frequency (28/40 kHz) ultrasound-assisted thawing (UAT) treatment on physicochemical quality, myofibril characteristics, and microstructure of large yellow croaker during frozen to refrigeration. The results revealed that UAT treatment retained a better performance, such as water-holding capacity (WHC), color, texture, and water distribution, and relieved disruption of microstructure, especially DUAT-28/40 treatment. The total volatile basic nitrogen (TVB-N) obtained the most desirable freshness property under the DUAT-28/40 treatment, as well as the free amino acids analysis. In addition, it reduced the myofibril denaturation during frozen to refrigeration, as shown in protein primary structure, infrared detection, and fluorescence intensity analysis. Therefore, DUAT-28/40 treatment could be a possible thawing method for relieving the quality deterioration of large yellow croaker during frozen to refrigeration. [ABSTRACT FROM AUTHOR]

This article explores the ionization characteristics of 19 amino acids using positive-ion Helium-Desorption Atmospheric Pressure Chemical Ionization Mass Spectrometry (He-DART-MS). The study reveals that multiple hydrogenation radical adducts of amino acids were observed during He-DART-MS analysis, with heterocyclic amino acids being more likely to produce these adducts. Aromatic amino acids, on the other hand, were less likely to exhibit this phenomenon. The findings provide valuable insights for the analysis of related compounds using He-DART-MS. The study received support from the Science and Technology Development Planning Project of Jilin Province and the Project for Outstanding Young Scientific and Technological Talents of Changchun University of Chinese Medicine. [Extracted from the article]

BACKGROUND RESULTS CONCLUSION The main edible part of the Lou onion is the pseudostem, which is highly valued for its distinctive flavour. However, harvesting decisions for the pseudostem are often based on size and market price, with little consideration given to flavour. By clarifying the growth of flavour in pseudostems, farmers and consumers may benefit from evidence‐based insights that help optimize harvesting time and maximize flavour quality.This study employed amino acid analysis and gas chromatography–ion migration spectroscopy (GC–IMS) to elucidate the compounds of the pseudostem across different growth phases, and 17 amino acids and 61 volatile substances. Subsequently, analysis revealed that 18 compounds, including arginine (Arg), aspartic acid (Asp), glutamic acid (Glu), valine (Val), (E)‐2‐nonenal, decanal, 2,4‐nonadienal, 2‐octenal, (Z)‐4‐decenal, 2,4‐decadienal benzeneacetaldehyde, linalool, eugenol, (Z)‐6‐nonen‐1‐ol, methyl anthranilate, 2‐acetylpyridine, 3‐sec‐butyl‐2‐methoxypyrazine, and 2,6‐dichlorophenol, were the key compounds in determining the flavour characteristics of the pseudostems, as assessed by taste activity value and relative odour activity value calculations. In addition, correlation analysis, focusing on five amino acids and 38 volatile compounds with variable importance for predictive components scores of >1, identified anisaldehyde, eugenol, (Z)‐6‐nonen‐1‐ol, 2,4‐decadienal, 3‐sec‐butyl‐2‐methoxypyrazine, Arg, Asp, and Val as the key differentiators and contributors to the pseudostems flavour profile.During the rapid growth of Lou onions just before the emergence of flower stems, the pseudostem exhibited the most prominent flavour, making this stage most suitable for harvesting compared to the regreening growth stage and the rapid growth period of the aerial bulbs. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The result of the implemented research is the development of a technology for sprouted lentil (lentil malt) production using cold plasma-treated aqueous solutions. The object of the study was lentil grain. The main technological task is to obtain high-quality lentil malt suitable for producing gluten-free beer and highly nutritious foods. The rationality of using cold plasma-treated aqueous solutions as an intensifier of lentil grain germination process and high-quality lentil malt disinfectant is experimentally proven. It is confirmed that using cold plasma-treated aqueous solutions can accelerate the process of lentil bean moistening by 2 times. The germination indicators of lentils also experienced positive changes, with germination energy increased by 8–16 %, germination capacity by 3–10 %, and sprout length by 12–29 %. An analysis of the amino acid composition of lentil grain and lentil malt was carried out. Thus, the experimental samples had an increased content of amino acids: non-essential by 2.7 %, essential by 3.6 %. There was also an increase in the content of B vitamins (B1, B2, B5, B9), as well as PP and C, which indicates an increased biological value of lentil malt obtained by the presented technologies. In addition, the work noted the steady antiseptic properties of activated aqueous solutions in relation to lentil malt. The intensive technology of obtaining lentil malt can be implemented in the industrial production of malt for the brewing industry. In addition, sprouted lentil beans have health-improving properties and can be used in the production of functional products. The presented technology of lentil bean malting will be in demand in the production of highly nutritious and healthy grain products and fermented beverages. [ABSTRACT FROM AUTHOR]

This study aimed to establish a pre-column derivatization-high performance liquid chromatography method for the determination of amino acids in Morindae officinalis Radix and evaluate its nutritional value by amino acid ratio coefficient method. The amino acid test solution of Morindae officinalis Radix was prepared by hydrochloric acid hydrolysis method. Phenyl isothiocyanate and triethylamine were used as pre-column derivatization reagents. The amino acid content was determined by high-performance liquid chromatography with Ultimate Amino Acid chromatographic column (4.6 mm x 250 mm, 5 μm), 0.1 mol/L anhydrous sodium acetate-acetonitrile as mobile phase, gradient elution, column temperature of 40°C, and detection wavelength of 254 nm. The nutritional value of amino acids was evaluated by amino acid ratio (RAA), amino acid ratio coefficient (RC), and ratio coefficient score (SRC). Systematic cluster analysis and principal component analysis were used in classification analysis. The linear relationship of 15 amino acids was good, and the correlation coefficient r ≥ 0.999 6. The total amino acid contents of 16 batches of Morindae officinalis Radix were between 17.87 mg/g and 102.15 mg/g. Fifteen kinds of amino acids were detected in all 16 samples, including 6 kinds of essential amino acids, accounting for 14.15% to 32.06%, and 8 kinds of medicinal amino acids, accounting for 45.20% to 56.31%. The limiting amino acids were threonine and leucine. The amino acid ratio coefficient was between 33.87 and 61.31. The correlation of amino acid composition of Morindae officinalis Radix was significant. Two principal components were proposed in principal component analysis, and the contribution rate of cumulative variance was 97.085%. 16 batches of Morindae officinalis Radix are divided into 3 categories. This method was simple and effective. It could effectively separate 15 kinds of amino acids, and had good precision and repeatability. It has high medicinal value and can provided a reference for quality evaluation and resource development of Morindae officinalis Radix. [ABSTRACT FROM AUTHOR]

The analysis of dietary supplements is far less regulated than pharmaceuticals, leading to potential quality issues. Considering their positive effect, many athletes consume supplements containing l-histidine and β-alanine. A new microfluidic method for the determination of l-histidine and β-alanine in dietary supplement formulations has been developed. For the first time, capacitively coupled contactless conductivity detection was employed for the microchip electrophoresis of amino acids in real samples. A linear relationship between detector response and concentration was observed in the range of 10–100 µmol L–1 for l-histidine (R2 = 0.9968) and β-alanine (R2 = 0.9954), while achieved limits of detection (3 × S/N ratio) were 4.2 µmol L–1 and 5.2 µmol L–1, respectively. The accuracy of the method was confirmed using recovery experiments as well as CE-UV-VIS and HPLC-UV-VIS techniques. The developed method allows unambiguous identification of amino acids in native form without chemical derivatization and with the possibility of simultaneous analysis of amino acids with metal cations. [ABSTRACT FROM AUTHOR]

Given the link between excessive salt consumption and hypertension, reducing salt levels in bread, an important staple food in Japan, is essential. γ-Aminobutyric acid (GABA) has a salty taste-enhancing effect in vivo, and its production is influenced by the type of spice extract in vitro. However, the effects of spices on GABA levels, total free amino acid composition, and taste quality in whole-wheat bread remain unclear. Therefore, this study aimed to investigate whether the addition of spice extracts, which do not affect bread flavor and taste, can increase the GABA level in low-salt whole-wheat bread and whether free amino acid content affects the taste quality of bread using an automatic home bread maker. Through free amino acid composition analysis and sensory testing, we evaluated the influence of six spice extracts on the composition of free amino acids, including GABA, in whole-wheat bread. We found that cumin and anise extracts were effective in increasing the GABA level to approximately twice that in whole-wheat bread. Moreover, both the preference and saltiness of the bread were favorable, indicating that these extracts are useful for reducing the salt content of whole-wheat bread. This study provides a theoretical basis for guiding industrial production. [ABSTRACT FROM AUTHOR]

Here, we report a proof-of-concept resistive pulse method for analyzing chiral amino acids utilizing metal-amino acid crystallization differences. This method involves introducing an amino acid sample solution into a micropipette through a pressure-driven flow. The sample then mixes with a metal ion solution inside the pipette, forming metal-amino acid crystals. The crystal size depends on the enantiomeric excess (x) of chiral amino acid samples. Large x values lead to large crystals. The crystal size difference is then reflected in the resistive pulse size as they block the ionic transport in a micropipette to different extents. We used Cd-cystine crystallization as a model system and found approximately five times the mean current pulse size difference for racemic (x = 0) and L-only (x = +1) cystine samples. A similar result was observed for aspartate. Our discovery opens up new opportunities for micro/nanoscopic chiral amino acid analysis, which can potentially be used in single-cell analysis. [ABSTRACT FROM AUTHOR]

Deep-sea coral communities, rich in various zoobenthos, have been discovered in the South China Sea (SCS) in recent years. Yet little is known about the trophic structure of these communities. In this study, we applied bulk isotope and compound-specific isotope analysis of amino acids (CSIA-AAs) to explore feeding strategies and estimate the trophic positions (TPs) and isotopic baseline for 6 deep-sea gorgonians and 7 other zoobenthos collected from a deep-sea coral community in the SCS. Bulk carbon and nitrogen isotope values (d13C and d15N) suggested that the zoobenthos in the community have a variety of food sources. Amino acids d15N results indicated that the TP is 2.3 ± 0.2 (mean ± 1s) for the deep-sea gorgonians and varies from 2.0 ± 0.3 (sponge) to 3.5 ± 0.5 (starfish) for other zoobenthos. The d15N values of phenylalanine revealed variable isotopic baselines ranging from +3.0 ± 0.9‰ to +11.7 ± 0.5‰, reflecting the incorporation of nitrogen from sources not limited to surface primary producers. Taken together, our data suggest that zoobenthos in the deep-sea coral community are mostly omnivorous, and their diet does not come solely from export production from the sea surface, with symbiotic bacteria as a potential important source. [ABSTRACT FROM AUTHOR]

Objective: Amino acid (AA) metabolism plays a vital role in liver regeneration. However, its measuring utility for post-hepatectomy liver regeneration under different conditions remains unclear. We aimed to combine machine learning (ML) models with AA metabolomics to assess liver regeneration in health and non-alcoholic steatohepatitis (NASH). Methods: The liver index (liver weight/body weight) was calculated following 70% hepatectomy in healthy and NASH mice. The serum levels of 39 amino acids were measured using ultra-high performance liquid chromatography-tandem mass spectrometry analysis. We used orthogonal partial least squares discriminant analysis to determine differential AAs and disturbed metabolic pathways during liver regeneration. The SHapley Additive exPlanations algorithm was performed to identify potential AA signatures, and five ML models including least absolute shrinkage and selection operator, random forest, K-nearest neighbor (KNN), support vector regression, and extreme gradient boosting were utilized to assess the liver index. Results: Eleven and twenty-two differential AAs were identified in the healthy and NASH groups, respectively. Among these metabolites, arginine and proline metabolism were commonly disturbed metabolic pathways related to liver regeneration in both groups. Five AA signatures were identified, including hydroxylysine, L-serine, 3-methylhistidine, L-tyrosine, and homocitrulline in healthy group, and L-arginine, 2-aminobutyric acid, sarcosine, beta-alanine, and L-cysteine in NASH group. The KNN model demonstrated the best evaluation performance with mean absolute error, root mean square error, and coefficient of determination values of 0.0037, 0.0047, 0.79 and 0.0028, 0.0034, 0.71 for the healthy and NASH groups, respectively. Conclusion: The KNN model based on five AA signatures performed best, which suggests that it may be a valuable tool for assessing post-hepatectomy liver regeneration in health and NASH. [ABSTRACT FROM AUTHOR]

Purpose: Rapid gastric emptying and intestinal absorption of beverages is essential for rapid rehydration, and certain amino acids (AA) may augment fluid delivery. Three sugar-free beverages, containing differing AA concentrations (AA + PZ), were assessed for fluid absorption kinetics against commercial sugar-free (PZ, GZ) and carbohydrate-containing (GTQ) beverages. Methods: Healthy individuals (n = 15–17 per study) completed three randomised trials. Three beverages (550–600 mL) were ingested in each study (Study 1: AA + PZ [17.51 g/L AA], PZ, GZ; Study 2: AA + PZ [6.96 g/L AA], PZ, GZ; Study 3: AA + PZ [3.48 g/L AA], PZ, GTQ), containing 3.000 g deuterium oxide (D2O). Blood samples were collected pre-, 2-min, 5-min, and every 5-min until 60-min post-ingestion to quantify maximal D2O enrichment (Cmax), time Cmax occurred (Tmax) and area under the curve (AUC). Results: Study 1: AUC (AA + PZ: 15,184 ± 3532 δ‰ vs. VSMOW; PZ: 17,328 ± 3153 δ‰ vs. VSMOW; GZ: 17,749 ± 4204 δ‰ vs. VSMOW; P ≤ 0.006) and Tmax (P ≤ 0.005) were lower for AA + PZ vs. PZ/GZ. Study 2: D2O enrichment characteristics were not different amongst beverages (P ≥ 0.338). Study 3: Cmax (AA + PZ: 440 ± 94 δ‰ vs. VSMOW; PZ: 429 ± 83 δ‰ vs. VSMOW; GTQ: 398 ± 81 δ‰ vs. VSMOW) was greater (P = 0.046) for AA + PZ than GTQ, with no other differences (P ≥ 0.106). Conclusion: The addition of small amounts of AA (3.48 g/L) to a sugar-free beverage increased fluid delivery to the circulation compared to a carbohydrate-based beverage, but greater amounts (17.51 g/L) delayed delivery. [ABSTRACT FROM AUTHOR]