RESUMO
Three pairs of enantiomers (1-3)-the new 12R-aloesol (1a) and two new fatty acids (2 and 3)-and one new natural product (4) together three known compounds (5-7) were isolated from a coral-reef-derived Streptomyces sp. SCSIO 66814. Their structures were determined through extensive spectroscopic analysis, chiral analysis, and single-crystal X-ray diffraction data. Compounds 2 and 3 were presumed to be intermediates for further generating homononactic acid (5) and nonactic acid, and the latter two molecules were able to act as precursors to form macrotetrolides with remarkable biological activity. The isolation of related precursors, compounds 2-5, provided more evidence to support the proposal of a plausible biosynthetic pathway for nonactic acid and its homologs. Additionally, (+)-1 exhibited a weak activity against DPPH radicals.
Assuntos
Antozoários , Cromonas , Streptomyces , Streptomyces/metabolismo , Streptomyces/química , Cromonas/química , Cromonas/isolamento & purificação , Cromonas/farmacologia , Estereoisomerismo , Antozoários/química , Animais , Cristalografia por Raios X , Ácidos Graxos/química , Ácidos Graxos/isolamento & purificação , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Produtos Biológicos/isolamento & purificação , Estrutura MolecularRESUMO
An ethyl acetate extract of a marine actinomycete strain, Nocardiopsis mentallicus SCSIO 53858, isolated from a deep-sea sediment sample in the South China Sea, exhibited anti-quorum-sensing (QS) activity against Chromobacterium violaceum CV026. Guided by the anti-QS activity, a novel active compound was isolated and purified from the extract and was identified as 2,3-dimethoxycinnamic acid (2,3-DCA) through spectral data analysis. At a concentration of 150 µg/mL, 2,3-DCA exhibited robust inhibitory effects on three QS-regulated traits of C. violaceum CV026: violacein production, swarming motility, and biofilm formation, with inhibition rates of 73.9%, 65.9%, and 37.8%, respectively. The quantitative reverse transcription polymerase chain reaction results indicated that 2,3-DCA can disrupt the QS system in C. violaceum CV026 by effectively suppressing the expression of QS-related genes, including cviR, vioA, vioB, and vioE. Molecular docking analysis revealed that 2,3-DCA hinders the QS system by competitively binding to the same binding pocket on the CviR receptor as the natural signal molecule N-hexanoyl-L-homoserine lactone. Collectively, these findings suggest that 2,3-DCA exhibits promising potential as an inhibitor of QS systems, providing a potential solution to the emerging problem of bacterial resistance.
Assuntos
Antibacterianos , Chromobacterium , Indóis , Simulação de Acoplamento Molecular , Percepção de Quorum , Percepção de Quorum/efeitos dos fármacos , Chromobacterium/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/química , Actinobacteria/química , Cinamatos/farmacologia , Cinamatos/isolamento & purificação , Cinamatos/química , Biofilmes/efeitos dos fármacos , Sedimentos Geológicos/microbiologia , Organismos Aquáticos , ChinaRESUMO
Seven new phenol derivatives, subversins A-E (1-5), subversic acid A (6) and epi-wortmannine G (7); one new natural product, 4-hydroxy-7-methoxyphthalide (8); and five known compounds (9-13) were isolated from the fungus Aspergillus subversicolor CYH-17 collected from the Haima cold seep. The structures and absolute configurations of these compounds were determined via NMR, MS, optical rotation, electronic circular dichroism (ECD) calculation, X-ray diffraction analysis and comparison with the literature. Compounds 2 and 5 were two pairs of enantiomers. All compounds were tested for their α-glucosidase and acetylcholinesterase (AChE) inhibitory activity, antioxidant activity and antibacterial activity, but no obvious activity was observed among these studied compounds.
Assuntos
Acetilcolinesterase , Aspergillus , Fenol , Fenóis , FungosRESUMO
PURPOSE: The aim of the study was to evaluate the value of lung ultrasound (LUS) in patients with cardiogenic shock treated by venoarterial extracorporeal membrane oxygenation (VA-ECMO). METHODS: A retrospective study was conducted in Xuzhou Central Hospital from September 2015 to April 2022. Patients with cardiogenic shock who received VA-ECMO treatment were enrolled in this study. The LUS score was obtained at the different time points of ECMO. RESULTS: Twenty-two patients were divided into a survival group (n = 16) and a nonsurvival group (n = 6). The intensive care unit (ICU) mortality was 27.3% (6/22). The LUS scores in the nonsurvival group were significantly higher than those in the survival group after 72 h (P < 0.05). There was a significant negative correlation between LUS scores and PaO2/FiO2 and LUS scores and pulmonary dynamic compliance(Cdyn) after 72 h of ECMO treatment (P < 0.001). ROC curve analysis showed that the area under the ROC curve (AUC) of T72-LUS was 0.964 (95% CI 0.887 ~ 1.000, P < 0.01). CONCLUSION: LUS is a promising tool for evaluating pulmonary changes in patients with cardiogenic shock undergoing VA-ECMO. TRIAL REGISTRATION: The study had been registered in the Chinese Clinical Trial Registry(NO.ChiCTR2200062130 and 24/07/2022).
Assuntos
Oxigenação por Membrana Extracorpórea , Choque Cardiogênico , Humanos , Mortalidade Hospitalar , Pulmão/diagnóstico por imagem , Estudos Retrospectivos , Choque Cardiogênico/diagnóstico por imagem , Choque Cardiogênico/terapiaRESUMO
For exploring structurally diverse metabolites and uniquely metabolic mechanisms, we systematically investigated the chemical constituents and putative biosynthesis of Janibacter sp. SCSIO 52865 derived from the deep-sea sediment based on the OSMAC strategy, molecular networking tool, in combination with bioinformatic analysis. As a result, one new diketopiperazine (1), along with seven known cyclodipeptides (2-8), trans-cinnamic acid (9), N-phenethylacetamide (10) and five fatty acids (11-15), was isolated from the ethyl acetate extract of SCSIO 52865. Their structures were elucidated by a combination of comprehensive spectroscopic analyses, Marfey's method and GC-MS analysis. Furthermore, the analysis of molecular networking revealed the presence of cyclodipeptides, and compound 1 was produced only under mBHI fermentation condition. Moreover, bioinformatic analysis suggested that compound 1 was closely related to four genes, namely jatA-D, encoding core non-ribosomal peptide synthetase and acetyltransferase.
Assuntos
Actinobacteria , Actinomycetales , Actinomycetales/genética , Dicetopiperazinas/química , Ácidos Graxos/química , Fermentação , Estrutura MolecularRESUMO
Drug resistance is an important factor for treatment failure of gastric cancer. N6 -methyladenosine (m6 A) is the predominant mRNA internal modification in eukaryotes. The roles of m6 A modification in drug resistance of gastric cancer remains unclear. In the present study, the m6 A methylated RNA level was significantly decreased while the expression of m6 A demethylase fat mass and obesity-associated protein (FTO) was obviously elevated in cisplatin-resistant (SGC-7901/DDP) gastric cancer cells. Knockdown of FTO reversed cisplatin resistance of SGC-7901/DDP cells both in vitro and in vivo, which was attributed to the inhibition of Unc-51-like kinase 1 (ULK1)-mediated autophagy. Mechanistically, ULK1 expression was regulated in an FTO-m6 A-dependent and YTHDF2-mediated manner. Collectively, our findings indicate that the FTO/ULK1 axis exerts crucial roles in cisplatin resistance of gastric cancer.
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Cisplatino , Neoplasias Gástricas , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Apoptose , Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/uso terapêutico , Obesidade/genética , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genéticaRESUMO
Surfactins are natural biosurfactants with myriad potential applications in the areas of healthcare and environment. However, surfactins were almost exclusively produced by the bacterium Bacillus species in previous reported literatures, together with difficulty in isolating pure monomer, which resulted in making extensive effort to remove duplication and little discovery of new surfactins in recent years. In the present study, the result of Molecular Networking indicated that Limimaricola sp. SCSIO 53532 might well be a potential resource for surfacin-like compounds based on OSMAC strategy. To search for new surfactins with significant biological activity, further study was undertaken on the strain. As a result, ten new surfactins (1-10), along with twenty known surfactins (11-30), were isolated from the ethyl acetate extract of SCSIO 53532. Their chemical structures were established by detailed 1D and 2D NMR spectroscopy, HRESIMS data, secondary ion mass spectrometry (MS/MS) analysis, and chemical degradation (Marfey's method) analysis. Cytotoxic activities of twenty-seven compounds against five human tumor cell lines were tested, and five compounds showed significant antitumor activities with IC50 values less than 10 µM. Furtherly, analysis of structure-activity relationships revealed that the branch of side chain, the esterification of Glu or Asp residue, and the amino acid residue of position 7 possessed a great influence on antitumor activity.
Assuntos
Bacillus , Espectrometria de Massas em Tandem , Bactérias , Linhagem Celular Tumoral , Humanos , Espectroscopia de Ressonância MagnéticaRESUMO
Radiation-induced gastric injury is a serious adverse effect and reduces the efficacy of radiotherapy treatment. However, the mechanisms underlying radiation-induced stomach injury remain unclear. Here, mouse stomach and gastric epithelial cells were irradiated with different doses of X-ray radiation. The results showed that radiation induced gastric injury in vivo and in vitro. Differentially expressed functional mRNAs in irradiation-induced gastric tissues were screened from the Gene Expression Omnibus (GEO) database. We found that the expression of microtubule-associated serine/threonine kinase 1 (Mast1) was downregulated in mouse gastric tissues and gastric epithelial cells after irradiation. Furthermore, functional assays showed that knockdown of Mast1 inhibited growth and promoted apoptosis in gastric epithelial cells, while overexpression of Mast1 protected gastric epithelial cells from radiation damage. Mechanistically, Mast1 negatively regulated radiation-induced injury in gastric epithelial cells by inhibiting the activation of P38. The apoptosis caused by knockdown of Mast1 in gastric epithelial cells could be partially reversed by the P38 inhibitor SB203580. Moreover, data from several gastric cancer cell lines and online databases revealed that Mast1 was not involved in the development of gastric cancer. Collectively, our findings demonstrated that Mast1 is essential for radiation-induced gastric injury, providing a promising prognostic and therapeutic target.
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Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Neoplasias Gástricas/patologia , Estômago/patologia , Raios X/efeitos adversos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Apoptose , Proliferação de Células , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/genética , Prognóstico , Proteínas Serina-Treonina Quinases/genética , Estômago/lesões , Estômago/metabolismo , Estômago/efeitos da radiação , Neoplasias Gástricas/etiologia , Neoplasias Gástricas/metabolismo , Taxa de Sobrevida , Células Tumorais Cultivadas , Proteínas Quinases p38 Ativadas por Mitógeno/genéticaRESUMO
Deep-sea sediment-derived bacterium may make full use of self-genes to produce more bioactive metabolites to adapt to extreme environment, resulting in the discovery of novel metabolites with unique structures and metabolic mechanisms. In the paper, we systematically investigated the metabolites in structurally diversity and their biosynthesis from the deep-sea sediment-derived bacterium Agrococcus sp. SCSIO 52902 based on OSMAC strategy, Molecular Networking tool, in combination with bioinformatic analysis. As a result, three new compounds and one new natural product, including 3R-OH-1,6-diene-cyclohexylacetic acid (1), linear tetradepsipeptide (2), N1,N5-di-p-(EE)-coumaroyl-N10-acetylspermidine (3) and furan fatty acid (4), together with nineteen known compounds (5-23) were isolated from the ethyl acetate extract of SCSIO 52902. Their structures were elucidated by comprehensive spectroscopic analysis, single-crystal X-ray diffraction, Marfey's method and chiral-phase HPLC analysis. Bioinformatic analysis revealed that compounds 1, 3, 9 and 13-22 were closely related to the shikimate pathway, and compound 5 was putatively produced by the OSB pathway instead of the PKS pathway. In addition, the result of cytotoxicity assay showed that compound 5 exhibited weak cytotoxic activity against the HL-60 cell line.
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Actinomycetales , Produtos Biológicos , Bactérias , Ácidos Graxos/químicaRESUMO
BACKGROUND: Deterioration in frozen dough bread easily occurs in store, resulting in tremendous economic waste. Therefore, it is imperative to find natural additives to improve storage staling. The effects of mulberry leaf polysaccharides (MLP) were studied in terms of baking, retrogradation and microstructural aspects in frozen dough bread. RESULTS: The incorporation of MLP improved the specific volume and reduced the hardness of bread during room storage, with 1% MLP showing the best results. The results of X-ray diffraction and Fourier transform infrared spectroscopy showed that crystallinity was decreased and the formation of double helical structure was inhibited with the incorporation of MLP. Meanwhile, the results of low-field nuclear magnetic resonance demonstrated that the addition of MLP was advantageous for retarding water migration and distribution, with reduced water loss. It can be seen intuitively from scanning electron microscopy that MLP improved the gluten network with a smoother and flatter system. CONCLUSION: MLP improved the quality of bread during storage and delayed the degradation of internal structure, and can be used as an effective natural additive to improve the storage stability of baked food. 1% MLP showed the best results. © 2022 Society of Chemical Industry.
Assuntos
Pão , Morus , Pão/análise , Folhas de Planta , Polissacarídeos , Água/químicaRESUMO
BACKGROUND: Prenatal anxiety has been a significant public health issue globally, leading to adverse health outcomes for mothers and children. The study aimed to evaluate the sociodemographic characteristics, knowledge, attitudes, and practices (KAP), and anxiety level of pregnant women during the coronavirus disease 2019 (COVID-19) epidemic in Wuhan and investigate the influencing factors for prenatal anxiety in this specific context. METHODS: Pregnant subjects' KAP towards COVID-19 and their sociodemographics and pregnancy information were collected using questionnaires. The Zung Self-Rating Anxiety Scale (SAS) was used to assess anxiety status. Factors associated with the level of prenatal anxiety were analyzed by Pearson's chi-square test and multivariable logistic regression analyses. RESULTS: The prenatal anxiety prevalence in this population was 20.8%. The mean score of knowledge was 13.2 ± 1.1 on a 0 ~ 14 scale. The attitudes and practices data showed that 580/ 817 (71.0%) were very concerned about the news of COVID-19, 455/817 (55.7%) considered the official media to be the most reliable information source for COVID-19, and 681/817 (83.4%) were anxious about the possibility of being infected by COVID-19. However, only 83/817 (10.2%) worried about contracting COVID-19 infection through the ultrasound transducer during a routing morphology scan. About two-thirds 528/817 (64.6%) delayed or canceled the antenatal visits. Approximately half of them 410/817 (50.2%) used two kinds of personal protection equipments (PPEs) during hospital visits. Logistic regression analysis revealed that the influential factors for prenatal anxiety included previous children in the family, knowledge score, media trust, worry of contracting the COVID-19 infection and worry about getting infected with COVID-19 from the ultrasound probe antenatal care (ANC) schedule. CONCLUSION: Prenatal anxiety was prevalent among pregnant women in Wuhan during the outbreak of COVID-19. The current findings identified factors associated with the level of prenatal anxiety that could be targeted for psychological care.
Assuntos
Ansiedade/psicologia , COVID-19/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Complicações Infecciosas na Gravidez/psicologia , Adulto , Ansiedade/epidemiologia , Ansiedade/prevenção & controle , COVID-19/epidemiologia , COVID-19/prevenção & controle , China/epidemiologia , Estudos Transversais , Parto Obstétrico/psicologia , Feminino , Humanos , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/prevenção & controle , Cuidado Pré-Natal/psicologiaRESUMO
BACKGROUND: Patients often suffer moderate or even severe pain after total hip arthroplasty; such pain seriously affects early postoperative recovery. This study aimed to investigate the analgesic efficacy of ultrasound-guided transmuscular quadratus lumborum block combined with fascia iliaca compartment block for elderly patients undergoing total hip arthroplasty. METHODS: Fifty-four patients scheduled for total hip arthroplasty were included in this randomized controlled study. The patients were randomly assigned to receive only transmuscular quadratus lumborum block (group Q) or transmuscular quadratus lumborum block combined with fascia iliaca compartment block (group QF) with ultrasound guidance. Postoperatively in both groups, paracetamol 1 g was regularly administered at 6 h intervals and patient-controlled intravenous analgesia was administered. The primary outcome was cumulative sufentanil consumption via patient-controlled intravenous analgesia 24 h postoperatively. The secondary outcomes included pain degree, time to the first analgesic requirement, joint range of motion, quality of recovery, and the incidence of postoperative complications. RESULTS: Fifty patients were included, and their data were analyzed. The cumulative sufentanil consumption in group QF was significantly lower during the first 24 h after surgery than that in group Q, and the cumulative sufentanil consumption in group QF was reduced at 6-12 and 12-18 h after surgery. The postoperative pain intensity was lower in group QF than in group Q (linear mixed-effects model, the main effect of treatment: P < 0.001). Compared with group Q, group QF had higher quality of recovery and joint range of movement. The time to the first analgesic requirement was longer in group QF than in group Q (log-rank, P < 0.001). There was no statistically significant difference in complications postoperatively between the two groups. CONCLUSIONS: Our study provides a multimodal, opioid-sparing analgesic regimen for elderly patients undergoing total hip arthroplasty. The combination of transmuscular quadratus lumborum block and fascia iliaca compartment block provides a significant advantage for early postoperative functional recovery. Further studies are required to confirm the minimum effective dose. TRIAL REGISTRATION: The study was registered on the 21st December 2020 (retrospectively registered) on the Chinese Clinical Trial Registry: ChiCTR2000038686 .
Assuntos
Analgésicos/administração & dosagem , Artroplastia de Quadril/métodos , Bloqueio Nervoso/métodos , Dor Pós-Operatória/prevenção & controle , Acetaminofen/administração & dosagem , Idoso , Analgesia Controlada pelo Paciente/métodos , Feminino , Humanos , Masculino , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos , Método Simples-Cego , Sufentanil/administração & dosagem , Fatores de Tempo , Ultrassonografia de Intervenção/métodosRESUMO
OBJECTIVE: To investigate the effect of oridonin on the human acute lymphocytic leukemia cell line Jurkat and its mechanism. METHODS: Jurkat cells were cultured in vitro and treated with various concentrations (0, 1.25, 2.5, 5, and 10â µmol/L) of oridonin for different lengths of time (24, 48, and 72â hours). The proliferation of Jurkat cells was analyzed by MTT assay. The changes in nuclear morphology were evaluated by fluorescence microscopy at 12 hours after treatment with various concentrations of oridonin. The expression levels of Brg1, P53, and C-myc were determined by semi-quantitative Western blot in Jurkat cells treated with various concentrations of oridonin for 24â hours or 5â µmol/L oridonin for various lengths of time (0, 2, 6, 12, and 24â hours). The expression levels of P53 and C-myc and proliferation of Jurkat cells were evaluated after Brg1 expression was knocked down by Brg1-specific siRNA. RESULTS: Compared with the control group, the proliferation of oridonin-treated Jurkat cells was significantly inhibited in a concentration- and time-dependent manner (P<0.05). According to the florescence microscopic analysis, oridonin treatment led to nuclear pyknosis in Jurkat cells. Compared with the control group, Jurkat cells treated with 5â µmol/L oridonin had reduced expression of Brg1 and C-myc but elevated expression of P53. Brg1 knock-down led to a significant reduction in proliferation of Jurkat cells (P<0.05), up-regulated expression of P53, and down-regulated expression of C-myc. CONCLUSIONS: Oridonin can inhibit the proliferation of Jurkat cells, probably via the Brg1 signaling pathway.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , DNA Helicases/fisiologia , Diterpenos do Tipo Caurano/farmacologia , Proteínas Nucleares/fisiologia , Fatores de Transcrição/fisiologia , Proliferação de Células/efeitos dos fármacos , DNA Helicases/análise , Relação Dose-Resposta a Droga , Regulação para Baixo , Humanos , Células Jurkat , Proteínas Nucleares/análise , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Proteínas Proto-Oncogênicas c-myc/análise , Transdução de Sinais/fisiologia , Fatores de Transcrição/análise , Proteína Supressora de Tumor p53/análiseRESUMO
Our previous study identified round scad neuroprotective peptides with different characteristics. However, the intrinsic relationship between their structure and bioactivity, as well as their bioavailability, remains unclear. The aim of this study is to elucidate the bioavailability of these peptides and their structure-activity relationship against neuroinflammation. Results showed that the SR and WCP peptides were resistant to gastrointestinal digestion. Additionally, peptides SR, WCP, and WCPF could transport Caco-2 monolayers as intact peptides. The permeability coefficients (Papp) of SR, WCP, and WCPF in Caco-2 monolayer were (1.53 ± 0.01) × 10-5, (2.12 ± 0.01) × 10-5, and (8.86 ± 0.03) × 10-7 cm/s, respectively. Peptides SR, WCP, and WCPF, as promising inhibitors of JAK2 and STAT3, could attenuate the levels of pro-inflammatory cytokines and regulate the NFκB and JAK2/STAT3 signaling pathway in LPS-treated BV-2 cells. WCPF exerted the highest anti-inflammatory activity. Moreover, bioinformatics, molecular docking, and quantum chemistry studies indicated that the bioactivity of SR was attributed to Arg, whereas those of WCP and WCPF were attributed to Trp. This study supports the application of round-scad peptides and deepens the understanding of the structure-activity relationship of neuroprotective peptides.
Assuntos
Anti-Inflamatórios , Janus Quinase 2 , Peptídeos , Humanos , Relação Estrutura-Atividade , Peptídeos/química , Peptídeos/farmacologia , Células CACO-2 , Janus Quinase 2/metabolismo , Janus Quinase 2/química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Animais , Camundongos , Proteínas de Peixes/química , Proteínas de Peixes/farmacologia , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/química , Fator de Transcrição STAT3/genética , Simulação de Acoplamento Molecular , NF-kappa B/metabolismo , NF-kappa B/genética , NF-kappa B/químicaRESUMO
Frozen staple food, attributed to its favorable taste and convenience, has a promising development potential in the future. Frequent freezing and thawing, however, will affect its quality. This study simulated several freeze-thaw cycles (FTC) that may occur during the cold chain process of frozen oatmeal cooked noodles (FOCN) production to consumption. The quality changes and their mechanisms were elucidated using methods such as differential scanning calorimetry (DSC), low-field nuclear magnetic resonance (LF-NMR), Fourier-transform infrared spectroscopy (FTIR), confocal laser scanning microscopy (CLSM), texture analysis, and sensory evaluation. The freezable water content of the FOCN decreased because of the FTC treatment, and the relative content of total water in FOCN also decreased accordingly. The increase in ß-Turn after FTC induced disorder in the secondary structure of proteins, causing the protein microstructure to become loose and discontinuous, which in turn reduced the water-holding capacity of FOCN. Additionally, FTC reduced the chewiness and sensory score of FOCN. This research will contribute a theoretical foundation for optimizing the cold chain process.
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This study aimed to find a unique method to assess the textural properties of Niangao (glutinous rice cakes), to determine the relationship between the textural properties of rice cakes and the indicators of glutinous rice, and to identify the key indicators that significantly affect the textural properties of Niangao. The study encompassed the analysis of the chemical composition and pasting characteristics of 22 glutinous rice varieties, revealing the substantial impact of variety on lipid content, straight-chain starch content, and pasting performance. Subsequently, the textural features of the resulting Niangao were subjected to principal component analysis (PCA) to derive a mathematical method for evaluating their textural attributes, with the obtained scores employed in hierarchical cluster analysis (HCA) to identify 12 key textural characteristics. Further analysis using stepwise linear regression (SLR) demonstrated that the regression model incorporating final and peak viscosities of the glutinous rice significantly predicted the composite score of the Niangao's textural properties. This highlights the importance of final and peak viscosities as key indicators for assessing the textural quality of Niangao.
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There are numerous studies on the application of soybean whey protein in three-dimensional (3D) printing. In this study, the effects of soybean meal particles (5%, 6%, 7%, 8%, 9%, and 10%) and oil-phase concentrations (70%, 72%, 74%, 76%, and 78%) on the stability and 3D-printing performance of a soybean-meal-based high-internal-phase emulsion were investigated. The results showed that the particle size of the emulsion decreased with increasing soybean meal particle concentration, and that increasing the concentration of the oil phase improved the viscoelasticity of the emulsion. Rheological tests further showed that the higher storage modulus of the emulsion indicated better support and stability. The emulsion with 8% soybean meal-particles and 76% oil-phase concentration exhibited the best printing effect. This study provides an effective solution for the preparation of stabilized high-internal-phase emulsions of soybean meal particles suitable for 3D printing.
Assuntos
Emulsões , Glycine max , Tamanho da Partícula , Impressão Tridimensional , Reologia , Emulsões/química , Glycine max/química , Viscosidade , Proteínas do Soro do Leite/químicaRESUMO
The rich active hydroxyl groups on starch nanocrystals (SNC) surface limits its dispersion and stability in the aqueous phase. To address this issue, ozone modification for 0 (SNC), 0.5 (SNC-1), 1 (SNC-2), 1.5 (SNC-3), and 2 h (SNC-4) as compared to conventionally chemical methods was applied to functionally modify the SNC. The impact of ozone treatment on the structural and surface characteristics of waxy rice starch nanocrystals. The findings revealed that longer ozone treatment durations favored the formation of carbonyl groups in starch molecules. Initially, ozone oxidized the hydroxyl group of the macromolecule. Once the carbonyl groups formed, the cross-linking reaction occurred among starch nanocrystals through condensation reactions, leading to the increasing molecular orderliness. X-ray photoelectron spectroscopy, X-ray diffraction and Small-angle X-ray scattering analyses of SNC-2 supported this finding with a reduced O/C ratio, and implied that surface oxidation did not alter the crystal type but rather enhanced molecular hydration in an aqueous system, leading to increased interfacial thickness and fractal dimension. Additionally, ozone oxidation improved surface properties such as charge and hydrophobicity. Oxidized SNC also exhibited altered gelatinization properties due to surface degradation. This study offers a promising strategy for enhancing SNC surface properties, crucial for food science applications.
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The hydrophilicity of gelatin films obviously limits their application. In this work, novel protonated chitin nanofiber was prepared with green methods, surficial deacetylation combined with acidic and mechanical treatment. Composite films with excellent water and oxygen barrier properties were successfully prepared by blending O/W Pickering emulsions stabilized by chitin nanofibers with gelatin substrates. The films were characterized by Fourier-transform infrared, X-ray diffraction, mechanical properties, water and oxygen permeability, moisture content, water solubility, water contact angle and optical properties. The results demonstrated that the amino groups of chitin nanofibers bound to the carboxyl groups of gelatin via electrostatic interactions, which contributing to the excellent mechanical and barrier properties of composite films. The elongation at break of composite film (the concentration of chitin nanofiber was 0.2 wt%) was 2.66 times of gelatin film. And the water vapor and oxygen permeability of composite films lowered to 65.9 % and 52.9 %, respectively. The introduction of O/W Pickering emulsion significantly enhanced the hydrophobicity of gelatin-based film and the chitin nanofibers played a positive role in stabilizing the gelatin chains to a certain extent. This study expands the application fields of gelatin-based films and provides valuable technical route for the preparation of barrier films.
Assuntos
Quitina , Emulsões , Gelatina , Nanofibras , Oxigênio , Permeabilidade , Água , Gelatina/química , Quitina/química , Nanofibras/química , Emulsões/química , Água/química , Oxigênio/química , Interações Hidrofóbicas e Hidrofílicas , Solubilidade , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
To investigate the optimal delivery system of quercetin, in this paper, cellulose nanocrystals (CNCs) extracted from rice bran were used to stabilize the Pickering emulsion and Pickering emulsion gels (PEGs) with quercetin. To compare the emulsion properties, stability, antioxidation activity, encapsulation rate, and bioaccessibility of the quercetin, four emulsions of CNC Pickering emulsion (C), CNC Pickering emulsion with quercetin (CQ), CNC Pickering gel emulsion (CG), and CNC Pickering gel emulsions with quercetin (CQG) were prepared. All four emulsions exhibited elastic gel network structure and good stability. The quercetin significantly reduced the particle size, increased the stability, and improved the antioxidant capacity of CQ and CQG. Compared to C and CG, the ABTS+ radical scavenging capacities of CQ and CQG were respectively enhanced by 46.92% and 3.59%. In addition, CQG had a higher encapsulation rate at 94.57% and higher bioaccessibility (16.17) compared to CQ. This study not only indicated that CNC from rice bran could be exploited as an excellent stabilization particle for Pickering emulsions, but also provided a highly stable and bioaccessible delivery system for water-insoluble functional active factors.