RESUMO
Food allergies are a global food safety problem. Peanut allergies are common due, in part, to their popular utilization in the food industry. Peanut allergy is typically an immunoglobulin E-mediated reaction, and peanuts contain 17 allergens belonging to different families in peanut. In this review, we first introduce the mechanisms and management of peanut allergy, followed by the basic structures of associated allergens. Subsequently, we summarize methods of epitope localization for peanut allergens. These methods can be instrumental in speeding up the discovery of allergenicity-dependent structures. Many attempts have been made to decrease the allergenicity of peanuts. The structures of hypoallergens, which are manufactured during processing, were analyzed to strengthen the desensitization process and allergen immunotherapy. The identification of conformational epitopes is the bottleneck in both peanut and food allergies. Further, the identification and modification of such epitopes will lead to improved strategies for managing and preventing peanut allergy. Combining traditional wet chemistry research with structure simulation studies will help in the epitopes' localization.
Assuntos
Arachis , Hipersensibilidade a Amendoim , Humanos , Arachis/química , Hipersensibilidade a Amendoim/prevenção & controle , Alérgenos , Indústria Alimentícia , EpitoposRESUMO
Cu2 O microparticles with controllable crystal planes and relatively high stability have been recognized as a good platform to understand the mechanism of the electrocatalytic CO2 reduction reaction (CO2 RR). Herein, we demonstrate that the inâ situ generated Cu2 O/Cu interface plays a key role in determining the selectivity of methane formation, rather than the initial crystal plane of the reconstructed Cu2 O microparticles. Experimental results indicate that the methane evolution is dominated on all three different crystal planes with similar Tafel slopes and long-term stabilities. Density functional theory (DFT) calculations further reveal that *CO is protonated via a similar bridge configuration at the Cu2 O/Cu interface, regardless of the initial crystal planes of Cu2 O. The Gibbs free energy changes (ΔG) of *CHO on different reconstructed Cu2 O planes are close and more negative than that of *OCCOH, indicating the methane formation is more favorable than ethylene on all Cu2 O crystal planes.
RESUMO
Producing ammonia (NH3) by electrocatalytic N2 fixation is a promising and environmentally friendly strategy, in comparison to the Haber-Bosch process with high consumption of energy and CO2 emissions. Because of the extremely high bond energy, it is indispensable to explore valid catalysts to activate the triple bond. In this paper, Cr-doped CeO2 nanorods are developed to serve as non-noble-metal electrocatalysts for an electrocatalytic N2 reduction reaction. Introducing Cr into the catalyst leads to an increase of the oxygen vacancies. In a 0.1 M Na2SO4 solution, the Cr0.1CeO2 nanorods achieve a high Faradaic efficiency (3.84%) and a large NH3 yield (16.82 µg h-1 mgcat.-1) at -0.7 V versus reversible hydrogen electrode. The Cr0.1CeO2 nanorods also exhibit high stability during the reaction.
RESUMO
BACKGROUND: microRNAs can repress the expression of target genes by destabilizing their mRNAs or by inhibiting their translation. Our previous findings suggested that miR-193a-3p inhibited the progression of NSCLC both in vitro and in vivo. However, the biological processes and molecular pathways through which this miRNA exerts its positive effects are unknown. METHODS: To explore the molecular mechanisms by which miR-193a-3p inhibited NSCLC metastasis, we investigated the changes in the protein profile of SPC-A-1sci (highly metastatic) cells in response to the up-regulation of miR-193a-3p expression using a proteomics approach (iTRAQ combined with NanoLC-MS/MS). Changes in the profiles of the expressed proteins were verified using western blotting and were analyzed using the DAVID and STRING programs. RESULTS: In the two replicated experiments, 4962/4946 proteins were identified, and the levels of expression of 4923/4902 proteins were quantified. In total, 112 of these proteins were differentially expressed. Among them, the up-regulated levels of expression of two of the 62 proteins with up-regulated expression (PPP2R2A and GSN) and the down-regulated levels of expression four of the 50 proteins with down-regulated expression (LMNB2, UHRF1, G3BP1, and HNRNPU) were verified using western blotting. The bioinformatics analysis revealed the interactions and signaling networks of these differentially expressed proteins. CONCLUSION: miR-193a-3p inhibited the metastasis of lung cancer cells by deregulating the expression of tumor-related proteins. These findings may improve the understanding of the molecular mechanisms underlying the metastatic-inhibitory effect of miR-193a-3p on lung cancer cells.
Assuntos
MicroRNAs/metabolismo , Proteômica , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Análise por Conglomerados , Bases de Dados Factuais , Regulação para Baixo , Humanos , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Metástase Neoplásica , Proteínas de Neoplasias/metabolismo , Oligonucleotídeos Antissenso/metabolismo , Mapas de Interação de Proteínas , Espectrometria de Massas em Tandem , Regulação para CimaRESUMO
Interactions between plant polyphenols and food allergens may be a new way to alleviate food allergies. The non-covalent interactions between the major allergen from peanut (Ara h 2) with procyanidin dimer (PA2) were therefore characterized using spectroscopic, thermodynamic, and molecular simulation analyses. The main interaction between the Ara h 2 and PA2 was hydrogen bonding. PA2 statically quenched the intrinsic fluorescence intensity and altered the conformation of the Ara h 2, leading to a more disordered polypeptide structure with a lower surface hydrophobicity. In addition, the in vitro allergenicity of the Ara h 2-PA2 complex was investigated using enzyme-linked immunosorbent assay (ELISA) kits. The immunoglobulin E (IgE) binding capacity of Ara h 2, as well as the release of allergenic cytokines, decreased after interacting with PA2. When the ratio of Ara h 2-to-PA2 was 1:50, the IgE binding capacity was reduced by around 43 %. This study provides valuable insights into the non-covalent interactions between Ara h 2 and PA2, as well as the potential mechanism of action of the anti-allergic reaction caused by binding of the polyphenols to the allergens.
Assuntos
Hipersensibilidade a Amendoim , Proantocianidinas , Arachis/química , Antígenos de Plantas/química , Alérgenos/química , Proantocianidinas/metabolismo , Glicoproteínas/química , Imunoglobulina E/metabolismo , Polifenóis/metabolismo , Proteínas de Plantas/químicaRESUMO
Given that roasted peanut (Ro) products are commonly used in daily life, peanut allergenicity is a foremost concern. Analyzing the changes in the structure and potential allergenicity of individual allergens can promote the exploration of the structural basis of the alterations in the potential allergenicity of Ro. This work focused on four major allergens in raw peanut (Ra) and Ro. Structural changes were analyzed on the basis of circular dichroism, ultraviolet and fluorescence spectroscopy, and molecular dynamic simulation. The IgE recognition capability of allergens was assessed via western blot analysis. The IgE binding capacity of allergens was detected by conducting enzyme-linked immunosorbent assay. The potential allergenicity of allergens was evaluated using the KU812 cell degranulation model. The results showed that roasting induced different changes in the overall structures of allergens and altered the structures and electrostatic potential of IgE epitopes, especially Ara h 1 and Ara h 6. These alterations affected the potential allergenicity of allergens. Ara h 1 and Ara h 6 in Ro showed significantly enhanced IgE binding capacities and abilities to elicit KU812 cell degranulation, while Ara h 2 and Ara h 3 did not change significantly. For total protein, the roasted peanut protein showed decreased abilities to elicit KU812 cell degranulation. The results indicated that different allergens in Ro showed different changes of structures and potential allergenicity and that the conformational structure plays a crucial role in potential allergenicity of allergens.
Assuntos
Antígenos de Plantas , Hipersensibilidade a Amendoim , Arachis/química , Imunoglobulina E/metabolismo , Alérgenos/metabolismo , Proteínas de Plantas/química , Albuminas 2S de Plantas/químicaRESUMO
This study explored the effect of stirred media mill (SMM) processing on the acid-induced gelling properties of pea protein. Results showed that SMM treatment enhanced the gel strength from 75.06 g to 183.89 g and increased the water holding capacity from 46.64 % to 73.50 %. The minimum gelation concentration achieved for SMM-treated pea protein was 4 %, significantly lower than that of heat-pretreated pea protein (9 %). SMM decreased protein aggregate size from 104 µm to 180 nm. Microscopy analysis revealed that the small aggregates facilitated the formation of uniform gel networks with tight connections. Linear rheology indicated that small protein aggregates resulted in slower gelation rates with a higher G' for the formed gels. The SMM-pretreated protein gel showed strain hardening, shear thinning behaviors, and satisfactory stability to withstand large-amplitude oscillatory shear. Overall, SMM emerges as a promising technology for producing protein gel products with strong mechanical attributes and customizable rheological properties.
Assuntos
Géis , Proteínas de Ervilha , Pisum sativum , Reologia , Géis/química , Proteínas de Ervilha/química , Pisum sativum/química , Manipulação de Alimentos , Concentração de Íons de HidrogênioRESUMO
To discover metastasis-associated proteins within cancer cells, we used the isobaric tags for relative and absolute quantitation (iTRAQ) approach combined with nano liquid chromatography-tandem mass spectrometry (NanoLC-MS/MS) analysis to identify proteins that were differentially expressed between lung adenocarcinoma cancer cell lines SPC-A-1sci cells with high metastatic potential and parent SPC-A-1 cells with low metastatic potential. By employing biological and technical replicates, we identified 5818 nonredundant proteins and quantified 5443 proteins, 256 of which were differentially expressed in the two cell lines. Through si-RNA-mediated functional screens, Myosin heavy chain 9 (MYH9) and Copine III (CPNE3) were indicated as positively correlating with the migration and invasion properties of SPC-A1sci cells, and the same function of CPNE3 was confirmed in another lung cancer cell line, H1299. Furthermore, overexpressing CPNE3 promoted nonsmall-cell lung cancer (NSCLC) cell line (SPC-A-1 and XL-2) migration and invasion in vitro. Moreover, the targeted knock-down of CPNE3 inhibited the in vivo metastatic abilities of H1299 cells in mouse models. Lastly, immunohistochemistry revealed that the CPNE3 expression level was positively correlated with the clinical stage and TNM classification in NSCLC patients. Taken together, our results indicate that CPNE3 could play a critical role in NSCLC metastasis.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Metástase Neoplásica/genética , Proteínas de Neoplasias/isolamento & purificação , Fosfoproteínas/biossíntese , Animais , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Cromatografia Líquida , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Proteínas Motores Moleculares/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Proteínas de Neoplasias/genética , Fosfoproteínas/genética , Proteoma/análise , Espectrometria de Massas em TandemRESUMO
The serious harm of volatile organic compounds (VOCs) to the ecological environment and human health has attracted widespread attention worldwide. With economic growth and accelerated industrialization, the anthropogenic emissions of VOCs have continued to increase. The most crucial aspect is to choose the appropriate adsorbent, which is very important for the VOCs removal. The search for environmentally friendly VOCs treatment technologies is urgent. The adsorption method is one of the most promising VOCs emission reduction technologies with the advantages of high cost-effectiveness, simple operation, and low energy consumption. One of the most critical aspects is the selection of the appropriate adsorbent, which is very important for the removal of VOCs. This work provides an overview of the sources and hazards of VOCs, focusing on recent research advances in VOCs adsorption materials and the key factors controlling the VOCs adsorption process. A summary of the key challenges and opportunities for each adsorbent is also provided. The adsorption capacity for VOCs is enhanced by an abundant specific surface area; the most efficient adsorption process is achieved when the pore size is slightly larger than the molecular diameter of VOCs; the increase in the number of chemical functional groups contributes to the increase in adsorption capacity. In addition, methods of activation and surface modification to improve the adsorption capacity for VOCs are discussed to guide the design of more advanced adsorbents.
RESUMO
The interaction of flavonoid glycosides with milk protein and effects on the functional properties of flavonoid glycoside-ß-lactoglobulin complexes are still inexplicit. The noncovalent interactions between flavonoid glycosides including quercetin (QE), quercitrin (QI), and rutin (RU) with ß-lactoglobulin (ß-LG) were determined by computer molecular docking and multispectral technique analysis. The fluorescence quenching results indicated that the flavonoid glycosides formed stable complexes with ß-LG by the static quenching mechanism. The computer molecular docking and thermodynamic parameters analysis conclude that the main interaction of ß-LG-QE was via hydrogen bonding, while for ß-LG-QI and ß-LG-RU it is via hydrophobic forces. The order of binding affinity to ß-LG was QE (37.76 × 104 L mol-1) > RU (16.80 × 104 L mol-1) > QI (11.17 × 104 L mol-1), which indicated that glycosylation adversely affected the colloidal complex binding capacity. In this study, the physicochemical properties of the protein-flavonoid colloidal complex were determined. The analysis by circular dichroism spectroscopy demonstrated that flavonoid glycosides made the protein structure looser by inducing the secondary structure of ß-LG to transform from the α-helix and ß-sheet to random coils. The hydrophobicity of ß-LG decreased due to binding with flavonoid glycosides, while functional properties including foaming, emulsification, and antioxidant capacities of ß-LG were improved due to the noncovalent interactions. This study presents a part of the insight and guidance on the interactive mechanism of flavonoid glycosides and proteins and is helpful for developing functional protein-based foods.
Assuntos
Flavonoides , Glicosídeos , Flavonoides/química , Simulação de Acoplamento Molecular , Espectrometria de Fluorescência , Dicroísmo Circular , Lactoglobulinas/química , Ligação ProteicaRESUMO
Developing anode materials with high reversible capacity, fast redox kinetics, and stable cycling life for Na+ storage remains a great challenge. Herein, the VO2 nanobelts with oxygen vacancies supported on nitrogen-doped carbon nanosheets (VO2-x/NC) were developed. Benefitting from the enhanced electrical conductivity, the accelerated kinetics, the increased active sites as well as the constructed 2D heterostructure, the VO2-x/NC delivered extraordinary Na+ storage performance in half/full battery. Theoretical calculations (DFT) demonstrated that oxygen vacancies could regulate the adsorption ability for Na+, enhance electronic conductivity, as well as achieve rapid and reversible Na+ adsorption/desorption. The VO2-x/NC exhibited high Na+ storage capacity of 270 mAh g-1 at 0.2 A g-1, and impressive cyclic stability with 258 mAh g-1 after 1800 cycles at 10 A g-1. The assembled sodium-ion hybrid capacitors (SIHCs) could achieve maximum energy density/power output of 122 Wh kg-1/9985 W kg-1, ultralong cycling life with 88.4% capacity retention after 25,000 cycles at 2 A g-1, and practical applications (55 LEDs could be actuated for 10 min), promising to be utilized in a practicable Na+ storage.
RESUMO
In this study, macadamia oil-based oleogels were prepared using monoglyceride stearate (MG) as a gelator with a low critical gelation concentration (3.0 wt%). The physical properties of the oleogels were evaluated by polarized light microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, texture and rheological analysis. And the lipid digestion and oxidative stability of the macadamia oil were determined by pH titration and accelerated oxidation test, respectively. The results showed that the hardness, oil binding capacity, and thermal stability of the oleogels increased with increasing MG concentration, which was attributed to the formation of a network of MG crystals held together by van der Waals interactions and hydrogen bonds. Rheological analysis indicated that all the oleogels exhibited a thermally reversible solid-to-liquid transition and viscoelastic behavior at ambient temperatures. Moreover, the formation of oleogels increased fatty acid release during in vitro lipid digestion and improved the oxidative stability of the macadamia oil. In addition, the potential application of these oleogels as replacements for saturated fats in foods was demonstrated by creating a chocolate product where the cocoa butter was replaced with macadamia oil-based oleogels with a high degree of unsaturation. These results can provide guidance for the preparation of macadamia oil-based oleogels, which may increase their application in foods.
Assuntos
Lipólise , Macadamia , Ácidos Graxos , Estresse OxidativoRESUMO
This study investigated the impact of polymeric proanthocyanidins (PPC) on the physicochemical characteristics of maize starch with varying amylose content, and their potential interaction mechanism. PPC with a lower content (1 %) reduced the viscoelasticity of the high amylose maize starch (HAM) system, inhibited amylose rearrangement, and enhanced its fluidity. However, excessive PPC restrained the interaction between PPC and amylose. In contrast to HAM, PPC improved the gelation ability of waxy maize starch (WAM) as PPC concentration was raised. PPC suppressed the recrystallization of starch during storage, and PPC had a superior inhibition influence on the retrogradation of WAM in comparison to HAM. This indicated that amylopectin was more likely to interact with PPC than amylose. Hydrogen bonds were the main driving force between PPC and starch chains, which was clarified by Fourier transform-infrared, nuclear magnetic resonance, X-ray diffraction, iodine bonding reaction, and dynamic light scattering data. Additionally, the mechanism of interaction between PPC and the two starch components may be similar, and variance in physicochemical attributes can be primarily credited to the percentage of amylose to amylopectin in starch.
Assuntos
Proantocianidinas , Amido , Amido/química , Amilopectina/química , Amilose/química , Zea mays/química , PolifenóisRESUMO
Procyanidins are bioactive polyphenols that have a strong affinity to proteins. Beta-lactoglobulin (BLG) is widely used as an emulsifier in the food and other industries. This study evaluated the interaction between BLG and A-type procyanidin dimer (PA2) using the spectroscopic, thermodynamic, and molecular simulation. PA2 decreased the transmissivity and quenched the intrinsic fluorescence of BLG, suggesting that the two molecules formed a complex. The binding of PA2 reduced the surface hydrophobicity and altered the conformation of BLG with increasing the random coil regions. Thermodynamic and isothermal titration calorimetry analyses suggested that the main driving force of PA2-BLG interaction was hydrophobic attraction. Molecular docking simulations were used to identify the main interaction sites and forces in the BLG-PA2 complexes, which again indicated that hydrophobic interactions dominated. In addition, the influence of PA2 on the ability of BLG to form and stabilize O/W emulsions was analyzed. Emulsions formulated using BLG-PA2 complexes contained relatively small droplets (D4,3 ≈ 0.7 µm) and high surface potentials (absolute value >50 mV). Compared to BLG alone, BLG-PA2 complexes improved the storage stability of the emulsions. This study provides valuable new insights into the formation, properties, and application of protein-polyphenol complexes as functional ingredients in foods.
Assuntos
Lactoglobulinas , Proantocianidinas , Bovinos , Animais , Lactoglobulinas/química , Simulação de Acoplamento Molecular , Emulsões/química , PolifenóisRESUMO
Hepatocellular carcinoma (HCC) is one of the most lethal malignant cancers across the world. It has a poor prognosis and lacks effective therapies, especially for patients with advanced-stage cancer, indicating an urgent need for new therapies and novel therapeutic targets. Here, by screening the U.S. Food and Drug Administration drug library against HCC cell lines, we identified that flubendazole, a traditional anthelmintic drug, could prominently suppress HCC cells in vivo and in vitro. RNA sequence analysis and cellular thermal shift assays showed that flubendazole reduced the expression of PCSK9 protein by direct targeting. The increased expression of PCSK9 in HCC tissues was demonstrated to be correlated with poor prognosis, and the inhibitory ability of flubendazole was selectively dependent on PCSK9 expression. PCSK9 knockdown abolished the antitumor effects of flubendazole in HCC. Mechanistically, flubendazole inhibited the Hedgehog signaling pathway induced by PCSK9, resulting in the downregulation of smoothened (SMO) and GLI Family Zinc Finger 1 (Gli1). Moreover, combining flubendazole with lenvatinib was found more effective than administering lenvatinib only for HCC treatment in vivo and in vitro. These findings reveal the therapeutic potential of flubendazole against HCC and provide clues on new repurposed drugs and targets for cancer treatment.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/metabolismo , Pró-Proteína Convertase 9/farmacologia , Neoplasias Hepáticas/metabolismo , Reposicionamento de Medicamentos , Proliferação de Células , Linhagem Celular Tumoral , Proteínas Hedgehog/metabolismoRESUMO
Aims The aim of this study was to investigate the anti-tumor efficacy of brucine on intrahepatic cholangiocarcinoma (ICC). Methods ICC QBC939 cells were treated with brucine, cell viability, cell cycle and apoptosis were analyzed using CCK-8 and flow cytometry. The expression of COX-2 and apoptosis related proteins Casp3, Bax and Bcl-2 were detected by Western blot analysis. QBC939 cells were subcutaneously transplanted into nude mice and the mice were injected with brucine intraperitoneally. The expression of Ki67, COX-2 and apoptosis related proteins were detected by immunohistochemical staining and Western blot analysis. Results Brucine significantly inhibited the proliferation and cell cycle progression while promoted the apoptosis of QBC939 cells. The expression of the apoptotic proteins Casp3 and Bax was upregulated, while the expression of Bcl-2 and COX-2 was downregulated in QBC939 cells with brucine treatment. Moreover, the overexpression of COX-2 could antagonize the effects of brucine on QBC939 cells. In vivo, brucine inhibited subcutaneous tumor formation in nude mice, and the expression of Ki67, COX-2 and Bcl-2 decreased while the expression of Casp3 and Bax increased in tumor tissues from nude mice with brucine treatment. Conclusions Brucine can significantly inhibit the progression of cholangiocarcinoma in vitro and in vivo, and the mechanism may be related to the inhibition of COX-2 expression.
RESUMO
BACKGROUND: As a small G protein of Ras family, Ras-like-without-CAAX-1 (RIT1) plays a critical role in various tumors. Our previous study has demonstrated the involvement of RIT1 in promoting malignant progression of hepatocellular carcinoma (HCC). However, its underlying mechanism remains unclear. METHODS: Gene set enrichment analysis (GSEA) was conducted in the TCGA LIHC cohort to investigate the underlying biological mechanism of RIT1. Live cell imaging, immunofluorescence (IF) and flow cytometry assays were used to verify biological function of RIT1 in HCC mitosis. Subcutaneous xenografting of human HCC cells in BALB/c nude mice was utilized to assess tumor proliferation in vivo. RNA-seq, co-immunoprecipitation (Co-IP), mass spectrometry analyses, western blot and IF assays were employed to elucidate the mechanisms by which RIT1 regulates mitosis and promotes proliferation in HCC. RESULTS: Our findings demonstrate that RIT1 plays a crucial role in regulating mitosis in HCC. Knockdown of RIT1 disrupts cell division, leading to G2/M phase arrest, mitotic catastrophe, and apoptosis in HCC cells. SMC3 is found to interact with RIT1 and knockdown of SMC3 attenuates the proliferative effects mediated by RIT1 both in vitro and in vivo. Mechanistically, RIT1 protects and maintains SMC3 acetylation by binding to SMC3 and PDS5 during mitosis, thereby promoting rapid cell division and proliferation in HCC. Notably, we have observed an upregulation of SMC3 expression in HCC tissues, which is associated with poor patient survival and promotion of HCC cell proliferation. Furthermore, there is a significant positive correlation between the expression levels of RIT1, SMC3, and PDS5. Importantly, HCC patients with high expression of both RIT1 and SMC3 exhibit worse prognosis compared to those with high RIT1 but low SMC3 expression. CONCLUSIONS: Our findings underscore the crucial role of RIT1 in regulating mitosis in HCC and further demonstrate its potential as a promising therapeutic target for HCC treatment.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Camundongos , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Camundongos Nus , Proliferação de Células/genética , Mitose , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral , Proteínas Cromossômicas não Histona/metabolismo , Proteoglicanas de Sulfatos de Condroitina/genética , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas ras/metabolismoRESUMO
In this study, a novel lead-free perovskite heterojunction Cs2SnCl6/C3N4 composite was constructed and applied for photocatalytic NO purification. After design optimization, the Cs2SnCl6/C3N4 heterojunction exhibit excellent and stable photocatalytic NO purification ability under visible-light irradiation, which is significantly better than pristine Cs2SnCl6 and C3N4. Combined in-situ DRIFTS and electron spin resonance spin-trapping, the mechanism of Cs2SnCl6/C3N4 photocatalytic NO removal was revealed. Under visible-light irradiation, the photo-generated electrons on the conduction band of C3N4 would spontaneously migrate to the CB of Cs2SnCl6, leaving holes (h+) on the valence band of C3N4, contributing to efficiently segregated charge carriers and improved photocatalytic NO purification. Density functional theory calculations also revealed the directional electron transfer at the C3N4 and Cs2SnCl6 interface, in which the charge was migrated from C3N4 to Cs2SnCl6 induced by the internal electric field. This research sheds fresh light on the fabrication of Cs2SnCl6/C3N4 heterojunctions as well as its effective interfacial charge separation.
RESUMO
Pea protein (PP) was moderately hydrolyzed using four proteolytic enzymes including flavourzyme, neutrase, alcalase, and trypsin to investigate the influence of the degree of hydrolysis (DH) with 2%, 4%, 6%, and 8% on the structural and functional properties of PP. Enzymatic modification treatment distinctly boosted the solubility of PP. The solubility of PP treated by trypsin was increased from 10.23% to 58.14% at the 8% DH. The results of SDS-PAGE indicated the protease broke disulfide bonds, degraded protein into small molecular peptides, and transformed insoluble protein into soluble fractions with the increased DH. After enzymatic treatment, a bathochromic shift and increased intrinsic fluorescence were observed for PP. Furthermore, the total sulfhydryl group contents and surface hydrophobicity were reduced, suggesting that the unfolding of PP occurred. Meanwhile, the foaming and emulsification of PP were improved after enzymatic treatment, and the most remarkable effect was observed under 6% DH. Moreover, under the same DH, the influence on the structure and functional properties of PP from large to small are trypsin, alcalase, neutrase and flavourzyme. This result will facilitate the formulation and production of natural plant-protein-based products using PP.
RESUMO
As a natural pigment with high antioxidative activity, betanin is underutilized owing to less attention. This study aimed to investigate the impact of betanin on pasting, rheology and retrogradation properties of rice, potato and pea starches. Betanin decreased the peak, trough and final viscosity of rice and potato starches, but increased those of pea starch. Rheology measurements implied that betanin had the greatest effect on the hysteresis loops and dynamic modulus of potato starch. Betanin endowed starch pastes with a vivid red appearance and maintained the color of the starch pastes during storage. XRD analysis indicated that betanin weakened the diffraction intensities and reduced the crystallinity of the retrograded starches. Meanwhile, betanin reduced the short-range ordered structure of the retrograde starches. The results of DSC analysis found that betanin significantly depressed the retrogradation enthalpy and retrogradation rate, implying that the long-term retrogradation of starches was delayed. Furthermore, the changed morphology of the retrograded starches was observed. These results suggested that betanin could be applied as an excellent colorant and inhibitor of retrogradation in foods such as bread and pastry products.