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1.
J Adv Res ; 2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-38286301

RESUMO

INTRODUCTION: Oxidative stress is one of the major contributors to acute alcoholic liver injury (AALI), which is a common alcoholic liver disease. Quercetin and catechin are flavonoid antioxidants present in plant foods and possess chemopreventive and chemotherapeutic activities. Quercetin and catechin are often included in the same meal and ingested together. While they show cooperative actions against oxidative damage, the underlying mechanisms behind their counteracting effects against oxidative stress-induced AALI remain poorly understood. OBJECTIVES: The aim of this study was to understand the mechanism underlying the enhanced antioxidant effect of quercetin-catechin combination to alleviate AALI in rats. METHODS: The ethanol (EtOH)-treated rats and H2O2-treated liver cells were used to demonstrate the enhanced antioxidant effect of quercetin and catechin. Then we used RNA-sequencing to compare quercetin alone, catechin alone and quercetin-catechin combination and then identified the critical role of IKKα combining with gene silencing and overexpression techniques. Its transcription factor, FOXO3 was found through yeast one-hybrid assay, luciferase reporter assay, EMSA and ChIP assay. Finally, the interaction between quercetin, catechin and FOXO3 was verified through molecular docking, UV-Vis absorption spectroscopy, fluorescence spectroscopy, and CD spectroscopy. RESULTS: The study demonstrated the enhanced antioxidant effect of a quercetin-catechin combination in EtOH-treated rats and in H2O2-treated liver cells. Quercetin and catechin cooperatively inhibited IKKα/p53 pathway and activated Nrf2 signaling pathway. IKKα was a critical negative regulator in their joint action. FOXO3 bound to IKKα promoter to regulate IKKα transcription. Quercetin and catechin influenced FOXO3-IKKα binding through attaching directly to FOXO3 at different sites and altering FOXO3's secondary structures. CONCLUSION: Our study revealed the mechanism of quercetin and catechin against oxidative stress-induced AALI through jointly interacting with transcription factor. This research opens new vistas for examining the joint effect of therapeutics towards functional proteins and confirms the chemopreventive effects of multiple flavonoids via co-regulation.

2.
Food Chem ; 439: 138090, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38043280

RESUMO

This study was the first to compare the structural features, functional properties and in vitro digestibility of two protein concentrates produced from defatted sunflower meal via two different three-stage processes (chlorogenic acid removal-alkaline extraction-isoelectric precipitation versus chlorogenic acid removal-alkaline extraction-ultrafiltration; concentrates termed AI-SPC and AU-SPC, respectively). Compared with AI-SPC, AU-SPC with a darker brown color had much higher protein recovery yield and purity, much higher solubility at pH 4-7, higher oil-holding capacity, greater emulsifying and foaming capacities at pH 7 and 9, and slightly lower foaming capacity at pH 3. The bioavailability was higher for AU-SPC after oral-gastric-intestinal digestion. Moreover, AI-SPC occurred as clumps/lumps of particles, whilst AU-SPC appeared as flat blocks with continuous surfaces. AU-SPC was more negatively charged, and had a smaller particle size, less ß-sheet, more ß-turn, slightly more α-helix structure. These results confirmed the close relationship between protein production methods and its functional properties and digestibility.


Assuntos
Helianthus , Ultrafiltração , Ácido Clorogênico , Proteínas de Plantas/química , Solubilidade
3.
Foods ; 12(24)2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38137316

RESUMO

The effects of fermentation with lactic acid bacteria (LAB) and yeast on the aroma of samples were analyzed in this work. The volatile features of different soybean hydrolysates were investigated using both GC-MS and GC-IMS. Only 47 volatile flavor compounds (VFCs) were detected when using GC-IMS, while a combination of GC-MS and GC-IMS resulted in the identification of 150 compounds. LAB-yeast fermentation could significantly increase the diversity and concentrations of VFCs (p < 0.05), including alcohols, acids, esters, and sulfurs, while reduce the contents of aldehydes and ketones. Hierarchical clustering and orthogonal partial least squares analyses confirmed the impact of fermentation on the VFCs of the hydrolysates. Seven compounds were identified as significant compounds distinguishing the aromas of different groups. The partial least squares regression analysis of the 25 key VFCs (ROAV > 1) and sensory results revealed that the treatment groups positively correlated with aromatic, caramel, sour, overall aroma, and most of the key VFCs. In summary, fermentation effectively reduced the fatty and bean-like flavors of soybean hydrolysates, enhancing the overall flavor quality, with sequential inoculation proving to be more effective than simultaneous inoculation. These findings provided a theoretical basis for improving and assessing the flavor of soybean protein hydrolysates.

4.
Crit Rev Food Sci Nutr ; : 1-19, 2023 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37837407

RESUMO

The numerous health benefits of dietary fibers (DFs) justify their inclusion in human diets and biomedical products. Given the short- and long-term human impacts of the COVID-19 virus on human health, the potential of DFs in building immunity against gastrointestinal and respiratory disorders is currently receiving high attention. This paper reviews the physicochemical properties of DFs, together with their immune functions and effects on the gastrointestinal tract and respiratory system mainly based on research in the last ten years. Possible modes of action of DFs in promoting health, especially building immunity, are explored. We seek to highlight the importance of understanding the exact physical and chemical characteristics and molecular behaviors of DFs in providing specific immune function. This review provides a perspective beyond the existing recognition of DFs' positive effects on human health, and offers a theoretical framework for the development of special DFs components and their application in functional foods and other therapeutic products against gastrointestinal and respiratory disorders. DFs enhance immunity from gastrointestinal and respiratory diseases to promote host health.

5.
Mikrochim Acta ; 190(10): 383, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37697171

RESUMO

Covalent organic framework-coated magnetite particles (Fe3O4@COF) were synthesized and applied as the adsorbent to the selective capture of phthalate esters (PAEs) in liquid foods. Combined with the magnetic solid-phase extraction (MSPE) technology, a gas chromatography-tandem mass spectrometry (GC-MS/MS) method was employed for the separation and quantification of PAEs. Following optimization of the magnetic extraction and elution parameters, the developed analytical method offered a satisfactory linear range (0.1-5 µg L-1) with determination coefficients ranging from 0.9934 to 0.9975 for the five different PAEs studied. The limits of detection (LOD) were in the range 1.9-12.8 ng L-1. The recoveries ranged from 70.0 to 119.8% with a relative standard deviation (RSD) less than 9.7%. Density functional theory (DFT) calculations established that the dominant adsorption mechanism used by the COF to bind PAEs involved π-π stacking interactions. Results encourage the wider use of COF-based adsorbents and MSPE methods in the analytical determination of PAEs in foods.


Assuntos
Estruturas Metalorgânicas , Espectrometria de Massas em Tandem , Cromatografia Gasosa-Espectrometria de Massas , Extração em Fase Sólida , Fenômenos Magnéticos , Ésteres
6.
Curr Res Food Sci ; 7: 100568, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37654441

RESUMO

This study aimed to investigate the nutritional value of five commercial meal-replacement shakes, and mainly focused on the lipid digestion fates and fat-soluble vitamin bioavailability. Four out of five samples exhibited a low lipolysis level (37.33-61.42%), aligning with the intended objectives of these products. Although the remaining sample rich in diacylglycerol (DAG) had a higher lipolysis level (80.83%), the inherent low-calorie nature of DAG might compensate for this drawback. The release level of individual fatty acid was largely determined by the glycerolipid composition. Moreover, the strong positive correlation between lipid hydrolyzed products amounts and the fat-soluble vitamin bioavailability was observed. Surprisingly, one out of five samples can provide enough vitamin A and vitamin E for consumers as a total replacement of one or two regular meals. Consequently, the meal-replacement shakes hold the potential to emerge as healthy products for this fast-paced era if the composition and structure were carefully designed and calculated.

7.
Food Chem ; 429: 136912, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37480780

RESUMO

Hemp (Cannabis sativa L) seeds are rich in proteins of high nutritional value, which makes the study of beneficial properties of hemp seed proteins and peptides, such as hypotensive and hypoglycemic effects, increasingly attractive. The present results confirm the good processability and stability of the hemp protein hydrolysate obtained by enzymatic hydrolysis of non-dehulled hemp seed meal (NDHM). Six peptides with potential hypoglycemic activity were obtained by ethanol-graded precipitation, Nano LC-Q-Orbitrap-MS/MS mass spectrometry, and computerized virtual screening. Further, validation experiments for in vitro synthesis showed that TGLGR, SPVI, FY, and FR exhibited good α-glucosidase inhibitory activity, respectively. Animal experiments showed that the hemp protein peptides modulated blood glucose and blood lipids in hyperglycemic rats. These results indicate that hemp protein peptides can reduce blood glucose levels in hyperglycemic rats, suggesting that hemp proteins may be a promising natural source for the prevention and treatment of hyperglycemia.


Assuntos
Cannabis , Animais , Ratos , Simulação de Acoplamento Molecular , Hipoglicemiantes , Glicemia , Espectrometria de Massas em Tandem , Peptídeos
8.
Compr Rev Food Sci Food Saf ; 22(5): 3560-3601, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37458317

RESUMO

Regular consumption of fish promotes sustainable health while reducing negative environmental impacts. Fermentation has long been used for preserving perishable foods, including fish. Fermented fish products are popular consumer foods of historical and cultural significance owing to their abundant essential nutrients and distinct flavor. This review discusses the recent scientific progress on fermented fish, especially the involved flavor formation processes, microbial metabolic activities, and interconnected biochemical pathways (e.g., enzymatic/non-enzymatic reactions associated with lipids, proteins, and their interactions). The multiple roles of fermentation in preservation of fish, development of desirable flavors, and production of health-promoting nutrients and bioactive substances are also discussed. Finally, prospects for further studies on fermented fish are proposed, including the need of monitoring microorganisms, along with the precise control of a fermentation process to transform the traditional fermented fish to novel, flavorful, healthy, and affordable products for modern consumers. Microbial-enabled innovative fermented fish products that consider both flavor and health benefits are expected to become a significant segment in global food markets. The integration of multi-omics technologies, biotechnology-based approaches (including synthetic biology and metabolic engineering) and sensory and consumer sciences, is crucial for technological innovations related to fermented fish. The findings of this review will provide guidance on future development of new or improved fermented fish products through regulating microbial metabolic processes and enzymatic activities.


Assuntos
Alimentos , Microbiota , Animais
9.
J Oleo Sci ; 72(8): 799-810, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37468271

RESUMO

This study aimed to produce stable plastic fat with desired physicochemical characteristics and ω-6/ω-3 fatty acid ratio (1:1-4:1) from palm stearin (PS), flaxseed oil (FSO) and cottonseed stearin (CS) via enzymatic interesterification (EIE). For the first time, the EIE variables of the blends containing PS, FSO and CS were investigated and optimized through single-factor experiments and response surface design to achieve a high interesterification degree. The optimized enzymatic interesterification conditions were: 60°C, 6 wt% Lipase UM1, and 6 h. Lipase UM1 had a similar effect on ID values with commercial lipases. The EIE improved the compatibility of the lipid blends, with the interesterified product EIE-721 (7:2:1, PS: FSO:CS) being the best candidate base stock for shortening considering its solid fat content, desired ω-6/ω-3 fatty acid ratio, wide melting range, abundant ß' form crystal, and compact microstructure. This study provides a strategy to produce balanced ω-6/ω-3 fatty acid plastic fat through enzymatic interesterification and validates the application of Lipase UM1 in the preparation of plastic fat.


Assuntos
Ácidos Graxos Ômega-3 , Óleo de Semente do Linho , Óleos de Plantas/química , Óleo de Sementes de Algodão , Ácidos Graxos/química , Lipase/química , Esterificação , Óleo de Palmeira
10.
Food Chem ; 429: 136874, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37454616

RESUMO

This study addresses the limitations of konjac glucomannan (KGM) films in mechanical properties, hydrophobicity and antibacterial activities. For the first time, a zein-pectin nanoparticle-stabilized corn germ oil-oregano essential oil Pickering emulsion (ZPCEO) was incorporated into KGM, with the resulting film being further ionically crosslinked with Ca2+, Cu2+ or Fe3+. FTIR, SEM and EDS results showed that the metal ions were crosslinked with the hydroxyl and carbonyl groups of polysaccharides and uniformly distributed throughout the films (degree of crosslinking: Fe3+ > Cu2+ > Ca2+). Compared with pure KGM films, the ionic crosslinked ZPCEO/KGM (IL-ZPCEO/KGM) films have superior water resistance mechanical properties, and exhibit unique UV-blocking properties, antioxidant and antibacterial activities. The ZPCEO/KGM-Fe3+ film offered the best all-round properties, including the highest tensile strength, water resistance, UV-blocking capacity, and antimicrobial activity. Thus, ionic crosslinking of ZPCEO/KGM films can be applied to the preparation of food packaging for use in high humidity environments.


Assuntos
Nanopartículas , Origanum , Zeína , Embalagem de Alimentos , Zea mays , Pectinas , Emulsões , Água , Mananas , Antibacterianos/farmacologia
11.
Carbohydr Polym ; 317: 121091, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37364944

RESUMO

UV/H2O2 process is increasingly used to degrade carbohydrates, though the underlying mechanisms remain unclear. This study aimed to fill this knowledge gap, focusing on mechanisms and energy consumption involved in hydroxyl radical (•OH)-mediated degradation of xylooligosaccharides (XOSs) in UV/H2O2 system. Results showed that UV photolysis of H2O2 generated large amounts of •OH radicals, and degradation kinetics of XOSs fitted with a pseudo-first-order model. Xylobiose (X2) and xylotriose (X3), main oligomers in XOSs, were attacked easier by •OH radicals. Their hydroxyl groups were largely converted to carbonyl groups and then carboxy groups. The cleavage rate of glucosidic bonds was slightly higher than that of pyranose ring, and exo-site glucosidic bonds were more easily cleaved than endo-site bonds. The terminal hydroxyl groups of xylitol were more efficiently oxidized than other hydroxyl groups of it, causing an initial accumulation of xylose. Oxidation products from xylitol and xylose included ketoses, aldoses, hydroxy acids and aldonic acids, indicating the complexity of •OH radical-induced XOSs degradation. Quantum chemistry calculations revealed 18 energetically viable reaction mechanisms, with the conversion of hydroxy-alkoxyl radicals to hydroxy acids being the most energetically favorable (energy barriers <0.90 kcal/mol). This study will provide more understanding of •OH radicals-mediated degradation of carbohydrates.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Peróxido de Hidrogênio/química , Xilose , Xilitol , Poluentes Químicos da Água/química , Raios Ultravioleta , Cinética , Oxirredução , Radical Hidroxila/química , Hidroxiácidos , Purificação da Água/métodos
12.
Food Chem ; 423: 136319, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37187007

RESUMO

Organophosphorus pesticide (OP) residues pose a serious threat to human health, motivating the search for novel adsorbents and detection methods. Herein, defective copper-based metal organic frameworks (Cu-MOFs) were synthesized by the reaction of Cu2+ ions and 1,3,5-benzenetricarboxylate linkers in the presence of acetic acid. As the amount of acetic acid increased, the crystallization kinetics and morphology of the Cu-MOFs changed, leading to mesoporous Cu-MOFs with many large surface pores (defects). Adsorption studies of OPs revealed the defective Cu-MOFs showed faster pesticide adsorption kinetics and higher pesticide adsorption capacities. Density functional theory calculations showed that pesticide adsorption in the Cu-MOFs was mainly electrostatic. A dispersive solid phase extraction method was developed based on a defective Cu-MOF-6 for rapidly extracting pesticides from food samples. The method allowed pesticide detection over a wide linear concentration range, low limits of detection (0.0067-0.0164 µg L-1) and good recoveries in pesticide-spiked samples (81.03-109.55%).


Assuntos
Estruturas Metalorgânicas , Resíduos de Praguicidas , Praguicidas , Humanos , Cobre/química , Praguicidas/análise , Compostos Organofosforados , Estruturas Metalorgânicas/química , Adsorção
13.
Crit Rev Food Sci Nutr ; : 1-31, 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37074177

RESUMO

Many health problems including chronic diseases are closely associated with oxidative stress and inflammation. Tea has abundant phenolic compounds with various health benefits including antioxidant and anti-inflammatory properties. This review focuses on the present understanding of the impact of tea phenolic compounds on the expression of miRNAs, and elucidates the biochemical and molecular mechanisms underlying the transcriptional and post-transcriptional protective actions of tea phenolic compounds against oxidative stress- and/or inflammation-mediated diseases. Clinical studies showed that drinking tea or taking catechin supplement on a daily basis promoted the endogenous antioxidant defense system of the body while inhibiting inflammatory factors. The regulation of chronic diseases based on epigenetic mechanisms, and the epigenetic-based therapies involving different tea phenolic compounds, have been insufficiently studied. The molecular mechanisms and application strategies of miR-27 and miR-34 involved in oxidative stress response and miR-126 and miR-146 involved in inflammation process were preliminarily investigated. Some emerging evidence suggests that tea phenolic compounds may promote epigenetic changes, involving non-coding RNA regulation, DNA methylation, histone modification, ubiquitin and SUMO modifications. However, epigenetic mechanisms and epigenetic-based disease therapies involving phenolic compounds from different teas, and the potential cross-talks among the epigenetic events, remain understudied.

14.
Sci Total Environ ; 877: 162910, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36934944

RESUMO

Cadmium (Cd), as Group I carcinogen, can induce damage to various organs including the gut. It is of great importance to meet the rising demand for effective therapies against Cd-induced damage and investigate the mechanism. Flammulina velutipes is a popular edible mushroom, despite the well-known health benefits of Flammulina velutipes, little is known about the effect of its polysaccharide (FVP) against CdCl2-intestinal injury. In this study, a FVP (uronic acid, 5.10 %; degree of methylation, 41.24 %) was produced via hot water extraction (85 °C) and ethanol precipitation. The FVP contained eight major monosaccharides and exhibited good thermal stability at temperatures lower than 139.73 °C. FVP (100 mg/kg b. w., gavage for 4 weeks) alleviated CdCl2 (1.5 mg/kg b. w., gavage for 4 weeks)-induced intestinal inflammation and apoptosis, intestinal permeability alteration and intestinal barrier disruption. FVP increased the abundance of Bacteroides, whilst decreasing the abundance of Desulfovibrionales and Clostridium. FVP also restored the levels of short-chain fatty acids (SCFAs), including acetic, propionic, isobutyric, butyric, isovaleric and valeric acids. Correlation analysis indicated the interplays among the FVP, gut microbes, SCFAs, intestinal barrier/cells and gut inflammation. FVP enhances the metabolic functions of gut microbiota via functional pathways analyzed by KEGG database. Furthermore, gut microbial transplantation of FVP + CdCl2 group mice partially alleviated CdCl2 caused-gut damage. Thus, FVP may be an effective therapeutic agent against CdCl2-induced gut damage via SCFA-mediated regulation of intestinal inflammation and gut microbiota-related energy metabolism. This study may open a new avenue for developing alternative strategies to prevent CdCl2-caused injury.


Assuntos
Flammulina , Microbioma Gastrointestinal , Camundongos , Animais , Cádmio/farmacologia , Inflamação/induzido quimicamente , Polissacarídeos , Ácidos Graxos Voláteis
15.
Int J Biol Macromol ; 237: 124178, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36990417

RESUMO

This study aimed to prepare a complex of Cr (III) and garlic polysaccharides (GPs) and evaluate the in vitro and in vivo hypoglycemic activities of GPs and GP-Cr (III) complexes. The chelation of GPs with Cr (III) increased molecular weight, modified crystallinity, and altered morphological characteristics, through targeting the OH of hydroxyl groups and involving the C-O/O-C-O structure. The GP-Cr (III) complex had a higher thermal stability over 170-260 °C and higher stability throughout the gastrointestinal digestion. In vitro, the GP-Cr (III) complex exhibited a significantly stronger inhibitory effect against α-glucosidase compared with the GP. In vivo, the GP-Cr (III) complex at a high dose (4.0 mg Cr/kg body weight) generally had a higher hypoglycemic activity than the GP in (pre)-diabetic mice induced by a high-fat and high-fructose diet, based on indices like body weight, blood glucose levels, glucose tolerance, insulin resistance, insulin sensitivity, blood lipid levels, and hepatic morphology and function. Therefore, GP-Cr (III) complexes could be a potential Cr (III) supplement with an enhanced hypoglycemic activity.


Assuntos
Diabetes Mellitus Experimental , Alho , Resistência à Insulina , Camundongos , Animais , Hipoglicemiantes/farmacologia , Glicemia , Polissacarídeos/farmacologia , Antioxidantes/farmacologia , Peso Corporal
16.
Food Chem ; 416: 135677, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-36898341

RESUMO

This study aimed to support the pursuit of healthy oils and investigate the relationships between lipid compositions and digestion fates of diacylglycerol (DAG)-rich lipids using an in vitro digestion model. Soybean-, olive-, rapeseed-, camellia-, and linseed-based DAG-rich lipids (termed SD, OD, RD, CD, and LD, respectively) were selected. These lipids exhibited identical lipolysis degrees (92.20-94.36 %) and digestion rates (0.0403-0.0466 s-1). The lipid structure (DAG or triacylglycerol) was a more important factor affecting the lipolysis degree than other indices (glycerolipid composition and fatty acid composition). For RD, CD and LD with similar fatty acid compositions, the same fatty acid had different release levels, probably due to their different glycerolipid compositions (causing different distributions of the fatty acid in UU-DAG, USa-DAG and SaSa-DAG; U: unsaturated fatty acids, Sa: saturated fatty acids). This study provides insights into the digestion behaviors of different DAG-rich lipids and supports their food or pharmaceutical applications.


Assuntos
Diglicerídeos , Óleos , Triglicerídeos , Ácidos Graxos , Digestão
17.
Metabolites ; 13(2)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36837850

RESUMO

Quercetin is a flavonol found in edible plants and possesses a significant anticancer activity. This study explored the mechanism by which quercetin prevented liver cancer via inducing apoptosis in HepG2 cells. Quercetin induced cell proliferation and apoptosis through inhibiting YY1 and facilitating p53 expression and subsequently increasing the Bax/Bcl-2 ratio. The results revealed that YY1 knockdown promoted apoptosis, whilst YY1 overexpression suppressed apoptosis via direct physical interaction between YY1 and p53 to regulate the p53 signaling pathway. Molecular docking using native and mutant YY1 proteins showed that quercetin could interact directly with YY1, and the binding of quercetin to YY1 significantly decreased the docking energy of YY1 with p53 protein. The interactions between quercetin and YY1 protein included direct binding and non-bonded indirect interactions, as confirmed by cellular thermal shift assay, UV-Vis absorption spectroscopy, fluorescence spectroscopy and circular dichroism spectroscopy. It was likely that quercetin directly bound to YY1 protein to compete with p53 for the binding sites of YY1 to disrupt the YY1-p53 interaction, thereby promoting p53 activation. This study provides insights into the mechanism underlying quercetin's anticancer action and supports the development of quercetin as an anticancer therapeutic agent.

18.
J Phys Chem Lett ; 14(7): 1740-1747, 2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36758156

RESUMO

PtNi nanoalloys have demonstrated electrocatalysis superior to that of benchmark Pt/C catalysts for the oxygen reduction reaction (ORR), yet the underlying mechanisms remain underexplored. Herein, a PtNi/NC catalyst comprising PtNi nanoparticles (∼5.2 nm in size) dispersed on N-doped carbon frameworks was prepared using a simple pyrolysis strategy. Benefiting from the individual components and a hierarchical structure, the PtNi/NC catalyst exhibited outstanding ORR activity and stability (E1/2 = 0.82 V vs RHE and 8 mV negative shift after 20000 cycles), outperforming a commercial 20 wt % Pt/C catalyst (E1/2 = 0.81 V and 32 mV negative shift). A prototype zinc-air battery constructed using PtNi/NC as the air electrode catalyst achieved highly enhanced electrochemical performance, outperforming a battery constructed using Pt/C as the ORR catalyst. Density functional theory calculations revealed that the improved ORR activity of the PtNi nanoalloys originated from charge redistribution with a suitable metal d-band center to promote the formation of the ORR intermediates.

19.
Food Chem ; 405(Pt B): 134985, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36442238

RESUMO

This study explores cherry waste valorization through sustainable green approaches. Two low-methoxy rhamnogalacturonan I (RG-I) enriched pectins were produced via mild aqueous extraction from cherry pomaces before and after yeast fermentation (RCUP and RCFP: RG-I, 52.02% and 48.81%; methylation degree, 44.71% and 37.55%). Both pectins contained galacturonic acid, arabinose, galactose, rhamnose and glucose. Compared with RCFP, RCUP was a more linear pectin with higher Mw, wider Mw distribution, longer homogalacturonans (HGs) and shorter side chains. Fermentation increased protein, mannose, glucose and galactose contents, and decreased pectin yield, total phenolic/anthocyanin and rhamnose contents, melting temperature and enthalpy, degradation enthalpy, viscosity, storage and loss moduli. Fermentation induced a much greater loss of HG (from 43.55% to 14.65%) than RG-I (from 52.02% to 48.81%). RCUP and RCFP possessed significant antioxidant activities and exhibited satisfactory emulsifying effects at 2%. RCUP was a more effective emulsifier. RCFP had a higher hydroxyl radical scavenging capacity.


Assuntos
Galactose , Ramnose , Pectinas , Glucose
20.
Crit Rev Food Sci Nutr ; 63(19): 3386-3419, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34637646

RESUMO

The numerous health benefits of pectins justify their inclusion in human diets and biomedical products. This review provides an overview of pectin extraction and modification methods, their physico-chemical characteristics, health-promoting properties, and pharmaceutical/biomedical applications. Pectins, as readily available and versatile biomolecules, can be tailored to possess specific functionalities for food, pharmaceutical and biomedical applications, through judicious selection of appropriate extraction and modification technologies/processes based on green chemistry principles. Pectin's structural and physicochemical characteristics dictate their effects on digestion and bioavailability of nutrients, as well as health-promoting properties including anticancer, immunomodulatory, anti-inflammatory, intestinal microflora-regulating, immune barrier-strengthening, hypercholesterolemia-/arteriosclerosis-preventing, anti-diabetic, anti-obesity, antitussive, analgesic, anticoagulant, and wound healing effects. HG, RG-I, RG-II, molecular weight, side chain pattern, and degrees of methylation, acetylation, amidation and branching are critical structural elements responsible for optimizing these health benefits. The physicochemical characteristics, health functionalities, biocompatibility and biodegradability of pectins enable the construction of pectin-based composites with distinct properties for targeted applications in bioactive/drug delivery, edible films/coatings, nano-/micro-encapsulation, wound dressings and biological tissue engineering. Achieving beneficial synergies among the green extraction and modification processes during pectin production, and between pectin and other composite components in biomedical products, should be key foci for future research.


Assuntos
Alimentos , Pectinas , Humanos , Estrutura Molecular , Peso Molecular , Preparações Farmacêuticas
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