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Maillard reaction products (MRPs) derived from rice protein isolate hydrolysate and D-xylose, with or without L-cysteine, were developed as a potential meat flavoring. The combined impact of temperature (80-140 °C) and cysteine on fundamental physicochemical characteristics, antioxidant activity, and flavor of MRPs were investigated through assessments of pH, color, UV-visible spectra, fluorescence spectra, free amino acids, volatile compounds, E-nose, E-tongue, and sensory evaluation. Results suggested that increasing temperature would reduce pH, deepen color, promote volatile compounds formation, and reduce the overall umami and bitterness. Cysteine addition contributed to the color inhibition, enhancement of DPPH radical-scavenging activity and reducing power, improvement in mouthfulness and continuity, reduction of bitterness, and the formation of sulfur compounds responsible for meaty flavor. Overall, MRPs prepared at 120 °C with cysteine addition could be utilized as a potential meat flavoring with the highest antioxidant activity and relatively high mouthfulness, continuity, umami, meaty aroma, and relatively low bitterness.
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Metastatic recurrence and postoperative wound infection are two major challenges for breast cancer patients. In this study, a multifunctional responsive hydrogel system was developed for synergistic reoxygenation and chemo/photothermal therapy in metastatic breast cancer and wound infection. The hydrogel system was obtained by cross-linking Prussian blue-modified N-carboxyethyl chitosan (PBCEC) and oxidized sodium alginate using the amino and aldehyde groups on the polysaccharides, resulting in the formation of responsive dynamic imine bonds. Conditioned stimulation (e.g., acid microenvironment) enabled the controlled swelling of hydrogels as well as subsequent slow release of loaded doxorubicin (DOX). Additionally, this hydrogel system decomposed endogenous reactive oxygen species into oxygen to relieve the hypoxic tumor microenvironment and promote the healing of infected-wounds. Both in vitro and in vivo experiments demonstrated the synergistic reoxygenation and chemo/photothermal effects of the PB/DOX hydrogel system against metastatic breast cancer and its recurrence, as well as postoperative wound infection. Thus, the combination of reoxygenation and chemo/photothermal therapy represents a novel strategy for treating and preventing tumor recurrence and associated wound infection.
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Neoplasias de la Mama , Hipertermia Inducida , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Terapia Fototérmica , Hidrogeles/química , Infección de la Herida Quirúrgica/terapia , Línea Celular Tumoral , Fototerapia/métodos , Hipertermia Inducida/métodos , Doxorrubicina , Microambiente TumoralRESUMEN
The gluten protein content in whole-wheat flour is low, which affects the elasticity and viscosity of the dough. Enzymatic modification of the protein may result in a network that mimics gluten, which plays an important role in the processing of whole-wheat foods. In this study, the effects of Halomonas alkaliantartica laccase (LacHa) on the quality parameters of whole-wheat bread were investigated. The optimum dosage of LacHa was 4 U/100 g of whole-wheat flour. At this dosage, whole-wheat bread exhibited the best specific volume and optimum texture parameters. Laccase also extended the storage duration of whole-wheat bread. We analyzed the micro-structure of the dough to determine its gluten-free protein extractable rate and free sulfhydryl group content, and verify that LacHa mediates cross-linking of gluten-free proteins. The results demonstrated that the cross-linking of gluten-free protein by LacHa improves the texture of whole-wheat bread. As a flour improver, LacHa has great developmental and application potential in baked-food production.
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Lacasa , Triticum , Lacasa/metabolismo , Triticum/metabolismo , Pan/microbiología , Harina , Glútenes/químicaRESUMEN
A smart packaging film was developed employing the pH-indicating activity of elderberry anthocyanins to solve the problem of refrigerated food freshness monitoring. The effect of elderberry anthocyanins on the properties of gellan gum, gelatin composite films and preservation of fresh shrimp as an indicator of freshness was investigated. The results showed that the elderberry anthocyanin-gellan gum/gelatin film had improved on film thickness (7.8×10-2 mm), TS (tensile strength) (14.57×103 MPa), WVP (water vapor permeability) (36.96×10-8 g/m·s·Pa), and a reduced EAB (elongation at break) (17.92%), and water solubility (water-soluble time of 60.5 s). SEM (scanning electron microscopy) and FTIR (infrared spectrum analysis) showed excellent compatibility between its components. Moreover, the elderberry anthocyanin film exhibited good mechanical properties and pH indication effects. Therefore, the film can be considered suitable for maintaining the quality of fresh shrimp. The results could provide a reference for research and development into new active intelligent packaging films.
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Antocianinas , Sambucus , Antocianinas/química , Embalaje de Alimentos , Resistencia a la Tracción , Películas Cinematográficas , Concentración de Iones de HidrógenoRESUMEN
Carboxymethyl starch (CMS)/xanthan gum (XG) combinations with different ratios (CMS/XG: 1/1, 3/1, 5/1, 7/1, 9/1, w/w) were used as Pickering emulsion delivery systems to encapsulate pterostilbene (PTS) to improve its stability. The results showed that the Pickering emulsion prepared using CMS/XG combinations could effectively encapsulate PTS. When the mass ratio of CMS to XG was 1:1, the encapsulation efficiency reached 91.20 %. The spherical particles in the PTS emulsion were dissociated and homogenous. The results of backscattered light experiments and storage stability studies showed that the PTS emulsion system prepared using CMS/XG was uniform and stable, with no obvious phase separation or emulsion droplet coalescence. With an increase in the mass ratio of XG, the water distribution in the emulsion became more evenly distributed, and the aggregation of droplets was reduced. The PTS emulsion prepared using CMS/XG improved the storage retention percentage of PTS. The cumulative release of PTS in the simulated gastric fluid was significantly lower than that in simulated intestinal fluid. The Pickering emulsion prepared using CMS/XG combinations can be used as a delivery system for functional foods and help to develop an efficient and reliable release system for hydrophobic bioactive substances.
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Emulsiones , Emulsiones/química , Preparaciones de Acción RetardadaRESUMEN
To explore the influence of pH values on the properties of a compound system containing tea polyphenols (TPs) and low acyl gellan gum (LGG), the color, texture characteristics, rheological properties, water holding capacity (WHC), and microstructure of the compound system were measured. The results showed that the pH value noticeably affects the color and WHC of compound gels. Gels from pH 3 to 5 were yellow, gels from pH 6 to 7 were light brown, and gels from pH 8 to 9 were dark brown. The hardness decreased and the springiness increased with an increase in pH. The steady shear results showed that the viscosity of the compound gel solutions with different pH values decreased with increasing shear rates, indicating that all of the compound gel solutions were pseudoplastic fluids. The dynamic frequency results showed that the G' and Gâ³ of the compound gel solutions gradually decreased with increasing pH and that G' was higher than Gâ³. No phase transition occurred in the gel state under heating or cooling conditions at pH 3, indicating that the pH 3 compound gel solution was elastic. The WHC of the pH 3 compound gel was only 79.97% but the WHC of compound gels pH 6 and pH 7 was almost 100%. The network structure of the gels was dense and stable under acidic conditions. The electrostatic repulsion between the carboxyl groups was shielded by H+ with increasing acidity. The three-dimensional network structure was easily formed by an increase in the interactions of the hydrogen bonds.
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Although coprinoid mushrooms are widely known for the phenomenon of deliquescence and production of fungal laccases and extracellular peroxygenases, the genome structure and genetic diversity of coprinoid mushroom species have not been extensively studied. To reveal the genomic structure and diversity in coprinoid mushroom species, the genomes of five coprinoid mushroom species were compared and analyzed. A total of 24,303 orthologous gene families, including 89,462 genes, were identified in the five species. The numbers of core, softcore, dispensable, and private genes were 5617 (25.6%), 1628 (7.4%), 2083 (9.5%), and 12,574 (57.4%), respectively. Differentiation time analysis revealed that Coprinellus micaceus and Coprinellus angulatus differentiated approximately 181.0 million years ago. Coprinopsis cinerea and Coprinopsis marcescibilis differentiated approximately 131.0 million years ago, and they were differentiated from Candolleomyces aberdarensis approximately 176.0 million years ago. Gene family contraction and expansion analyses showed that 1465 genes and 532 gene families were expanded, and 95 genes and 134 gene families were contracted. Ninety-five laccase-coding genes were detected in the five species, and the distribution of the laccase-coding genes in the five species was not uniform. These data provide a reference for a deeper understanding of the genetic structure of the genomes of coprinoid mushroom species. Furthermore, this study provides a reference for follow-up studies on the genome structure of coprinoid mushroom species and the diversity of specific functional genes.
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Agaricales , Lacasa , Lacasa/genética , Agaricales/genética , GenómicaRESUMEN
AIM: Investigate the effects of different nitrogen sources on the metabolic characteristics of Sphingomonas paucimobilis during gellan gum (GG) production was helpful for developing optimized conditions that are widely applicable to all GG production processes. METHODS AND RESULTS: We compared the effects of organic nitrogen (ON) and inorganic nitrogen (IN) sources during GG production using transcriptome sequencing. Our results showed that compared with the IN source, the ON source effectively improved the cell number and GG production of S. paucimobilis during fermentation. There were significant differences in gene transcription levels between the ON and IN groups at different fermentation times. CONCLUSIONS: The transcriptional levels of multiple genes in the pathways from α-D-glucose-1P to glyceraldehyde-3P were reduced in the ON group, whereas those of multiple genes in the pathways from glyceraldehyde-3P to acetyl-CoA were significantly enhanced in the ON group after 12 h of fermentation. The transcription levels of multiple genes participating in the citrate cycle and upstream of fatty acid metabolism pathways were significantly enhanced in the ON group after 12 h of fermentation. Except for the transcripts per million (TPMs) of pgm and rfbA genes in ON, which were significantly higher than those in IN at 12 h after fermentation, the TPMs of the majority of genes in ON were significantly lower than those in IN. The transcription levels of genes participating in the transformation of N-acetyl-D-glucosamine (GlcNAc) to UDP-N-acetyl-alpha-D-glucosamine (UDP-GlcNAc) were enhanced in the ON group during the fermentation process.
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Nitrógeno , Transcriptoma , Gliceraldehído , Polisacáridos Bacterianos/metabolismo , Uridina DifosfatoRESUMEN
Rutin is a biologically active polyphenol, but its poor water solubility and low bioavailability limit its application to the food industry. We investigated the effect of ultrasound treatment on the properties of rutin (R) and whey protein isolate (WPI) using spectral and physicochemical analysis. The results revealed that there was covalent interaction between whey protein isolate with rutin, and the binding degree of whey isolate protein with rutin increased with ultrasound treatment. Additionally, solubility and surface hydrophobicity of WPI-R complex improved with ultrasonic treatment, and a maximum solubility of 81.9 % at 300 W ultrasonic power. The ultrasound treatment caused the complex to develop a more ordered secondary structure, resulting in a three-dimensional network structure with small and uniform pore sizes. This research could provide a theoretical reference for studying protein-polyphenol interactions and their applications in food delivery systems.
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Polifenoles , Rutina , Proteína de Suero de Leche/química , Solubilidad , Interacciones Hidrofóbicas e HidrofílicasRESUMEN
Antimicrobial peptides (AMPs) have attracted considerable interest in the past decade due to their advantages for tackling antibiotic resistance. They exhibit potential antimicrobial activity through unique cell membrane destruction mechanism based on their net charge, hydrophobic properties, and α-helix. In this work, a series of HJH peptides was rationally designed and synthesized. The antimicrobial activity and cytotoxicity assays indicated that HJH-5 and HJH-6 containing hydrophobic residues and helices displayed prominent antimicrobial activity and mild cytotoxicity, respectively. These peptides may be developed for combatting microbial infections.
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Antiinfecciosos , Péptidos Catiónicos Antimicrobianos , Péptidos Catiónicos Antimicrobianos/farmacología , Péptidos Catiónicos Antimicrobianos/química , Péptidos Antimicrobianos , Membrana Celular , Farmacorresistencia Microbiana , Antiinfecciosos/farmacología , Antiinfecciosos/química , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Antibacterianos/químicaRESUMEN
BACKGROUND: Protein-polysaccharide gels have significant and unique properties in food formulations. However, they are susceptible to environmental influences like heat and pH. The present work investigated the effects of acid and alkali treatments on the gel properties and microstructural changes of whey protein isolate (WPI) high acyl gellan gum (HG). RESULTS: The results showed that the pH had a strong effect on the gel hardness, water-holding capacity (WHC), free sulfhydryl groups (-SH), and other properties of the composite gel. The hardness reached a maximum level of 282.50 g and the best WHC was 98.33% at pH 7, indicating that a suitable pH could promote this cross-linking between the WPI and HG molecules. The rheological analysis demonstrated that the pH affected the gel formation time. Meanwhile, the gel formation time reached a maximum at pH 7, and the gel's storage modulus G' value was the largest in the final state. Fourier transform infrared spectroscopy (FTIR) results showed that pH affected the interaction between WPI and HG. Scanning electron microscopy (SEM) analysis also indicated that the composite gel formed a three-dimensional network structure at pH 7-9. CONCLUSION: These results could broaden the application of protein-polysaccharide gels in food and delivery systems. © 2023 Society of Chemical Industry.
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Polisacáridos Bacterianos , Proteína de Suero de Leche/química , Geles , Polisacáridos Bacterianos/química , Reología , Concentración de Iones de HidrógenoRESUMEN
Cyclic arginine-glycine-aspartic (RGD) peptides that specifically bind to integrin ανß3 have been developed for drug delivery, tracers, and imaging for tumor diagnosis and treatment. Herein, a series of polycyclic RGD peptides containing dual, tri, and tetra rings were designed and synthesized through sortase A-mediated ligation. An in vitro test on cell adhesion inhibition indicated that the RGD peptide containing tricylic structure exhibited outstanding potency and selectivity for ανß3 integrin.
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Integrina alfaVbeta3 , Integrina beta3 , Aminoaciltransferasas , Proteínas Bacterianas , Ciclización , Cisteína Endopeptidasas , Integrina alfaVbeta3/metabolismo , Integrina beta3/metabolismo , Oligopéptidos/químicaRESUMEN
The members of the glutathione S-transferase (GST) superfamily often exhibit functional overlap and can compensate for each other. Their concentrations in serum are considered as disease biomarkers. A global and quantitative evaluation of serum GSTs is therefore urgent, but there is a lack of efficient approaches due to technological limitations. GSH magnetic beads were examined for their affinity to enrich GSTs in serum, and the enriched GSTs were quantitatively targeted using a Q Exactive HF-X mass spectrometer in parallel reaction monitoring (PRM) mode. To optimize the quantification of GST peptides, sample types, trypsin digestion, and serum loading were carefully assessed; a biosynthetic method was employed to generate isotope-labeled GST peptides, and instrumental parameters were systematically optimized. A total of 134 clinical sera were collected for GST quantification from healthy donors and patients with four liver diseases. Using the new approach, GSTs in healthy sera were profiled: 14 GST peptides were quantified, and the abundance of five GST families was ranked GSTM > GSTP > GSTA > MGST1 > GSTT1, ranging from 0.1 to 4 pmol/L. Furthermore, combining the abundance of multiple GST peptides could effectively distinguish different types of liver diseases. Quantification of serum GSTs through targeted proteomics, therefore, has apparent clinical potential for disease diagnosis.
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Glutatión Transferasa , Espectrometría de Masas en Tándem , Cromatografía Liquida , Glutatión , Glutatión Transferasa/análisis , Humanos , Hígado , Péptidos , Proteómica/métodosRESUMEN
Demand for antimicrobial packaging films is growing due to public attention to food safety. The structures and properties of gellan gum-guar gum blend films incorporated with nisin were investigated in this paper. Fourier transform infrared spectroscopy, rheological analyses showed intermolecular interactions among gellan gum, guar gum, and nisin. Furthermore, scanning electron microscopy and thermogravimetric analysis also indicated higher compatibility of the blend film components and better thermal stability than the gellan gum film. Tensile strength (TS), elongation at break (EAB) and water vapor permeability (WVP) of the blend films were enhanced with the addition of guar gum. The TS of the blend film reached 2.89 × 103 MPa, the EAB increased to 67.99%, and the WVP increased to 1.80 × 10-5 g/mm·s·Pa. Additionally, the film with nisin had antibacterial activity for Bacillus subtilis. The results demonstrated that a homogenous and smooth antimicrobial film with gellan gum, guar gum, and nisin could be a good option of antimicrobial packaging film for food preservation. PRACTICAL APPLICATION: This work investigated blend package films of gellan gum and guar gum incorporated with nisin. The results showed compatibility and thermal stability of the film were improved with adding a certain amount of guar gum, and also antibacterial activity for Bacillus subtilis of the blend film with nisin. Therefore, it can be used to the development of antimicrobial packaging films.
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Embalaje de Alimentos/instrumentación , Galactanos/química , Mananos/química , Nisina/química , Gomas de Plantas/química , Polisacáridos Bacterianos/química , Antibacterianos/química , Antibacterianos/farmacología , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/crecimiento & desarrollo , Plásticos Biodegradables/química , Plásticos Biodegradables/farmacología , Microscopía Electrónica de Rastreo , Nisina/farmacología , Permeabilidad , Espectroscopía Infrarroja por Transformada de Fourier , Vapor/análisis , Resistencia a la TracciónRESUMEN
A two-stage culture (with controlled sucrose concentrations and temperatures) of Sphingomonas paucimobilis for gellan gum production has been previously investigated. Herein, the mechanism of a two-stage culture favoring gellan gum overproduction was revealed by analysing the cell-membrane permeability and the proteomics for gellan gum biosynthesis. The two-stage culture, resulted in 79.8% increased content of unsaturated fatty acids, and 3.95% increased ratio of unsaturated to saturated fatty acids in the cell membrane. Moreover, cell membrane permeability increased and thus further enhanced gellan gum biosynthesis. Proteomic analysis results indicated that 13 identified protein spots were involved in energy generation, glycogen biosynthesis, and glycolysis. These findings revealed that two-stage culture impellel carbon flux flow toward gellan gum biosynthesis.
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2-Deoxy-D-glucose (2-DG) is a non-metabolizable glucose analogue and competitive inhibitor of glycolysis. Effect of 2-DG on gellan gum biosynthesis by Sphingomonas paucimobilis ATCC31461 were studied in this research. The concentration and the addition time of 2-DG significantly affected the biomass and gellan gum accumulation. The maximum gellan gum yield of 20.78 g/L was obtained with the addition of 50 µg/L of 2-DG at 24 h. The mechanism of 2-DG addition favoring to gellan production was revealed by determining the activities of key enzymes. Results indicated that 2-DG addition increased the activities of glucosyltransferase and inhibited UDP-glucose pyrophosphorylase activity. The result indicated that 2-DG inhibited glycolysis and changed metabolic driving force to activate gellan gum biosynthesis metabolism pathways.
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Desoxiglucosa/farmacología , Glucólisis/efectos de los fármacos , Polisacáridos Bacterianos/biosíntesis , Sphingomonas/metabolismoRESUMEN
Pullulan, produced by Aureobasidium pullulans strain, has been broadly used in the food and medical industries. However, relatively little is known concerning the molecular basis of pullulan biosynthesis of this strain. In this paper, the effect of different concentrations of (NH4)2SO4 on pullulan fermentation was studied. Proteomics containing two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS) were used to analyze the protein with different expressions of A. pullulans cells between the nitrogen limitation and nitrogen repletion. Maximum pullulan production reached 37.72 g/L when 0.6 g/L of initial (NH4)2SO4 was added. Excess nitrogen source would impel carbon flux flow toward biomass production, but decreased the pullulan production. Nitrogen limitation in A. pullulans seemed to influence the flux change of carbon flux flow toward exopolysaccharide accumulation. The findings indicated that 12 identified protein spots were involved in energy-generating enzymes, antioxidant-related enzymes, amino acid biosynthesis, glycogen biosynthesis, glycolysis, protein transport, and transcriptional regulation. These results presented more evidence of pullulan biosynthesis under nitrogen-limited environment, which would provide a molecular understanding of the physiological response of A. pullulans for optimizing the performance of industrial pullulan fermentation.
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Ascomicetos/metabolismo , Proteínas Fúngicas/metabolismo , Glucanos/biosíntesis , Nitrógeno/metabolismo , Ascomicetos/química , Ascomicetos/genética , Ascomicetos/crecimiento & desarrollo , Fermentación , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Nitrógeno/análisis , ProteómicaRESUMEN
Effect of pullulan (PUL) on the pasting, rheological properties of rice starch (RS) was investigated. The swelling power, amylose leaching, and confocal laser scanning microscopy (CLSM) observation of the samples were also conducted to explore the possible interaction between starch and pullulan. Rapid visco-analysis (RVA) showed that PUL significantly changed viscosity parameters of rice starch-pullulan (RS-PUL) mixtures. Dynamic rheological measurements revealed that the modulus (G', Gâ³) of the mixtures increased with the increase of pullulan concentration from 0.01% to 0.07%, but then decreased with the increase of pullulan concentration from 0.07% to 0.50%. The pasting and rheological properties of samples indicated that pullulan could blend well with rice starch and promote the gelatinization of starch granules at low concentration of pullulan, but suppress the gelatinization of starch granules at high concentration of pullulan. The results of swelling power, leached amylose and CLSM observation of samples further suggest that the interaction between starch and pullulan occurred in the RS-PUL system and the interaction was hypothesized to be responsible for these results.
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Glucanos/química , Oryza/química , Almidón/química , Amilosa/química , Reología , ViscosidadRESUMEN
Effect of uracil on the pullulan production, biomass and uridine phosphorylase (UPase) activity was studied in this research. Uracil was found to enhance pullulan accumulation and the addition time of uracil was crucial to pullulan production. Pullulan yield of 49.07 g/L was achieved by adding 5mM uracil at 48 h, by comparison to 37.72 g/L obtained with the control. UPase activity could not be detected at early growth stage of Aureobasidium pullulans, but stimulated by added uracil at logarithmic phase and stationary phase. The time course study on the fermentation of pullulan demonstrates that pullulan production was not closely associated with biomass accumulation. Results indicate that the increased pullulan yield brought by uracil was correlated with UPase activity.
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Ascomicetos/efectos de los fármacos , Ascomicetos/metabolismo , Glucanos/biosíntesis , Uracilo/farmacología , Ascomicetos/enzimología , Fermentación/efectos de los fármacos , Cinética , Uridina Fosforilasa/metabolismoRESUMEN
In this study, the effect of H2O2-induced oxidative stress on gellan gum production and cell growth were investigated. Gellan gum production was improved and cell growth was inhibited by H2O2. A multiple H2O2 stresses with different concentrations were developed to optimize gellan gum production. A maximal gellan gum yield (22.52 g/L), which was 35.58 % higher than the control, was observed with 2, 2, 3, 4 mmol/L H2O2 added at 6, 12, 18, 24 h, respectively. Moreover, UDP-glucose pyrophosphorylase activity and glucosyltransferase activity were increased with H2O2 stresses. This new strategy of multiple H2O2-induced oxidative stresses would be further applied to gellan gum production in future study.