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1.
Food Res Int ; 195: 114988, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39277259

RESUMEN

This study investigated the effect of gellan gum (GG) and glucono-δ-lactone (GDL) on the acid-induced gel properties of pea protein isolate (PPI) pretreated with media milling. The inclusion of GG substantially enhanced the gel hardness of PPI gel from 18.69 g to 792.47 g though slightly reduced its water holding capacity (WHC). Rheological analysis showed that GG increased storage modulus (G') and decreased damping factor of gels in the small amplitude oscillatory shear region and transformed its strain thinning behavior into weak strain overshoot behavior in the large amplitude oscillatory shear region. SEM revealed that GG transformed the microstructure of gel from a uniform particle aggregate structure to a chain-like architecture composed of filaments with small protein particles attached. Turbidity and zeta potential analysis showed that GG promoted the transformation of PPI from a soluble polymer system to an insoluble coagulant during acidification. When GG content was relatively high (0.2 %-0.3 %), high GDL content increased the electrostatic interaction between PPI and GG molecules, causing their rapid aggregation into a dense irregular aggregate structure, further enhancing gel strength and WHC. Overall, GG and GDL can offer the opportunity to modulate the microstructure and gel properties of acid-induced PPI gels, presenting potential for diversifying food gel design strategies through PPI-GG hybrid systems.


Asunto(s)
Geles , Gluconatos , Lactonas , Proteínas de Guisantes , Polisacáridos Bacterianos , Reología , Polisacáridos Bacterianos/química , Lactonas/química , Geles/química , Gluconatos/química , Proteínas de Guisantes/química , Concentración de Iones de Hidrógeno
2.
J Sci Food Agric ; 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39271480

RESUMEN

BACKGROUND: The structure of proanthocyanidins (PC) contains a large number of active phenolic hydroxyl groups, which makes it have strong antioxidant capacity. This study investigated the structural and functional properties of ovalbumin (OVA) modified by its interaction with PC. RESULTS: It was found that on increasing the concentration ratio of PC to OVA from 10:1 to 40:1, the free amino and total sulfhydryl contents of OVA decreased from 470.59 ± 38.77 and 29.81 ± 0.31 nmol mg-1 to 96.61 ± 4.55 and 21.22 ± 0.78 nmol mg-1, respectively, and the free sulfhydryl content increased from 7.65 ± 0.41 to 9.48 ± 0.58 nmol mg-1. These results indicated that CN and CS bonds were formed and PC was covalently linked with OVA. The PC content in the OVA-PC conjugates increased from 281.93 ± 12.92 to 828.81 ± 46.09 nmol mg-1 on increasing the concentration ratio of PC to OVA from 10:1 to 40:1. The contents of α-helix and ß-turn of OVA decreased, and the contents of ß-sheet and random coil increased, confirmed by circular dichroism. The tertiary structure of OVA was also altered according to the results of fluorescence and ultraviolet absorption spectra. The surface hydrophobicity of OVA-PC conjugates decreased with increasing bound polyphenol content. The conjugation of OVA to PC significantly improved its emulsification and antioxidant activity and denaturation temperature. CONCLUSION: This study may provide valuable information for improving OVA's functional properties and its PC conjugates for applications in the food industry. © 2024 Society of Chemical Industry.

4.
Food Chem ; 458: 140237, 2024 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-38996488

RESUMEN

In this study, S-methyl derivatives of dithiocarbamates (DTCs) were shown to significantly enhance chemiluminescence (CL) between Ce(IV) and efficient and environmentally friendly nitrogen-doped carbon dots (NCDs). Based on the elucidation of the CL mechanisms, an innovative approach involving high-performance liquid chromatography coupled with N-CDs and CL detection (HPLC-CDCL) was proposed. The developed method was successfully applied to the highly sensitive detection of three DTC fungicides (dimethyl dithiocarbamate, ethylene bisdithiocarbamate, and propylene bisdithiocarbamate) in tea. The recovery of the established method ranged 70.51-116.45%, with relative standard deviations (RSD) of <9.40%. The limit of detection (S/N = 3) was as low as 0.19 µg/L (as CS2), which is superior to the previous methods and comparable to UPLC-tandem mass spectrometry (MS/MS). Moreover, the proposed approach does not require solid-phase extraction and offers excellent selectivity. This study proposes a novel method for the detection of DTCs in the food safety and environmental fields.


Asunto(s)
Carbono , Contaminación de Alimentos , Nitrógeno , , Tiocarbamatos , Cromatografía Líquida de Alta Presión/métodos , Té/química , Tiocarbamatos/química , Tiocarbamatos/análisis , Carbono/química , Contaminación de Alimentos/análisis , Nitrógeno/química , Puntos Cuánticos/química , Límite de Detección , Fungicidas Industriales/análisis , Fungicidas Industriales/química
5.
Nurse Educ Today ; 140: 106272, 2024 09.
Artículo en Inglés | MEDLINE | ID: mdl-38851019

RESUMEN

BACKGROUND: Empathy and self-efficacy for smoking cessation counseling can be enhanced through smoking cessation training. Narrative videos and virtual reality (VR) games have been applied in medical education, but their application in smoking cessation training is limited and understudied. OBJECTIVES: To evaluate the effect of smokers' narrative videos and mini-VR games on nursing students' empathy towards smokers (State Empathy Scale), confidence in practicing empathy, self-efficacy in smoking cessation counseling, and learning satisfaction. DESIGN: An open-labeled randomized controlled trial, registration number: NCT05440877 (ClinicalTrials.gov). SETTING AND PARTICIPANTS: Master of nursing students from the University in Hong Kong who enrolled in a smoking cessation course. METHODS: All students attended a tutorial including case-based discussions and role-play. The intervention group could additionally access the narrative videos and mini-VR games of smokers' cases. Linear mixed models and Cohen's d were used to evaluate the intervention effect on the self-reported learning outcomes after the intervention. RESULTS: 26 students enrolled in this trial, with 13 in each trial arm. All completed the trial. Post-test state empathy scores were significantly higher in the control group than in the intervention group (Cohen's d = 0.814, p = 0.049). No significant group differences were observed in the change of confidence in practicing empathy (ß = -11.154, p = 0.073), self-efficacy (ß = 4.846, p = 0.096), and students' learning satisfaction (Cohen's d = 0.041, p = 0.917). Both groups showed a significant increase in self-efficacy post-test (p < 0.001). CONCLUSIONS: Narrative videos showing smoking scenes and reluctance to quit, and our mini-VR games may weaken nursing students' empathy towards smokers. Smoking cessation training involving narrative videos should be modified. Debriefing and guidance to understand smokers' difficulties and express empathy are needed. VR games for smoking cessation training can involve more frame stories and challenging tasks to increase engagement.


Asunto(s)
Consejo , Empatía , Autoeficacia , Cese del Hábito de Fumar , Estudiantes de Enfermería , Juegos de Video , Humanos , Femenino , Masculino , Hong Kong , Estudiantes de Enfermería/psicología , Estudiantes de Enfermería/estadística & datos numéricos , Cese del Hábito de Fumar/métodos , Cese del Hábito de Fumar/psicología , Juegos de Video/psicología , Adulto , Consejo/métodos , Consejo/educación , Narración , Grabación en Video , Educación de Postgrado en Enfermería/métodos
6.
Foods ; 13(12)2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38928819

RESUMEN

Indole-3-propionic acid (IPA) is a plant growth regulator with good specificity and long action. IPA may be harmful to human health because of its accumulation in vegetables and fruits. Therefore, in this study, the properties of the interaction between calf thymus DNA (ctDNA) and IPA were systematically explored using multispectroscopic and computational modeling approaches. Analysis of fluorescence spectra showed that IPA binding to ctDNA to spontaneously form a complex was mainly driven by hydrogen bonds and hydrophobic interaction. DNA melting analysis, viscosity analysis, DNA cleavage study, and circular dichroism measurement revealed the groove binding of IPA to ctDNA and showed that the binding did not significantly change ctDNA confirmation. Furthermore, molecular docking found that IPA attached in the A-T rich minor groove region of the DNA. Molecular dynamics simulation showed that DNA and IPA formed a stable complex and IPA caused slight fluctuations for the residues at the binding site. Gel electrophoresis experiments showed that IPA did not significantly disrupt the DNA structure. These findings may provide useful information on the potential toxicological effects and environmental risk assessments of IPA residue in food at the molecular level.

7.
J Glob Antimicrob Resist ; 38: 6-11, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38723711

RESUMEN

OBJECTIVE: This study aimed to analyse the bacterial composition, distribution, drug sensitivity, and clinical characteristics of patients with coronavirus disease 2019 (COVID-19) who develop bacterial co-infections. METHODS: We conducted a retrospective study of 184 patients with COVID-19 admitted between December 2022 and January 2023. Data on gender, age, length of hospital stay, pneumonia classification, underlying diseases, invasive surgery, hormone therapy, inflammation indicators, and other relevant information were collected. Samples of sputum, bronchoscopy sputum, alveolar lavage fluid, middle urine, puncture fluid, wound secretions, and blood were collected for pathogen isolation, identification, and drug sensitivity testing. RESULTS: The majority of patients with COVID-19 with bacterial co-infection were elderly and had underlying diseases. Invasive surgery and hormone therapy were identified as risk factors for co-infections. Laboratory analysis showed reduced lymphocyte counts and elevated levels of C-reactive protein and procalcitonin. The most common pathogens in co-infections were Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa. The detection rate of drug-resistant strains, including methicillin-resistant S. aureus, carbapenem-resistant K. pneumoniae, carbapenem-resistant A. baumannii, carbapenem-resistant P. aeruginosa, and carbapenem-resistant E. coli, increased with the severity of pneumonia. CONCLUSION: Respiratory tract infections were the most common site of bacterial co-infection in patients with COVID-19. Severe cases were more susceptible to multidrug-resistant pathogens, leading to a higher mortality rate. Timely control and prevention of co-infection are crucial for improving the prognosis of patients with COVID-19.


Asunto(s)
COVID-19 , Coinfección , SARS-CoV-2 , Humanos , COVID-19/complicaciones , Coinfección/microbiología , Coinfección/virología , Coinfección/epidemiología , Masculino , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Anciano , Factores de Riesgo , SARS-CoV-2/aislamiento & purificación , Infecciones Bacterianas/microbiología , Adulto , Antibacterianos/uso terapéutico , Antibacterianos/farmacología , Anciano de 80 o más Años , Bacterias/aislamiento & purificación , Bacterias/clasificación , Bacterias/efectos de los fármacos , Pruebas de Sensibilidad Microbiana
9.
Int J Pharm ; 654: 123964, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38430948

RESUMEN

The purpose of this study was to develop a novel baicalein (BAI) loaded glycymicelle ophthalmic solution with small molecule phytochemical glycyrrhizin as nanocarriers and to explore this solution's potential as an antimicrobial agent against ocular infections. The optimized BAI glycymicelles had a high encapsulation efficiency (98.76 ±â€¯1.25 %), a small particle size (54.38 ±â€¯2.41 nm), a uniform size distribution (polydispersity index = 0.293 ±â€¯0.083), and a zeta potential of -28.3 ±â€¯1.17 mV. The BAI glycymicelle ophthalmic solution exhibited an excellent short-term storage stability. BAI glycymicelles significantly increased the apparent solubility and in vitro release capability of BAI. The BAI glycymicelle ophthalmic solution exhibited no hen's egg-chorioallantoic membrane' irritation and strong in vivo ocular tolerance in rabbits. The BAI glycymicelles noticeably enhanced the in vivo corneal permeation. The BAI glycymicelles also precipitated increased in vitro antioxidant activity and significantly improved in vitro antipathogen activities. Various antimicrobial mechanisms, including the destruction of the bacterial cell wall, damage to the bacterial cell membranes, interruptions to the biofilm structure, and the apoptosis of bacteria, were inflicted on BAI glycymicelles. These findings provided useful knowledge regarding the development of a novel ophthalmic solution and formulation of BAI.


Asunto(s)
Antiinfecciosos , Flavanonas , Animales , Conejos , Flavanonas/farmacología , Córnea/metabolismo , Antiinfecciosos/farmacología , Soluciones Oftálmicas/química , Administración Oftálmica , Tamaño de la Partícula
10.
Nurs Open ; 11(3): e2126, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38439120

RESUMEN

AIM: To explore the mediating role of psychological capital between authentic leadership and innovative behaviour among Chinese nurses. DESIGN: A cross-sectional study. METHODS: In December 2021, online surveys were delivered among nurses from 37 hospitals in Anhui Province by convenience sampling approach. The data was collected using the Chinese version of the Authentic Leadership Questionnaire, Nurse Psychological Capital Questionnaire and Nurse Innovative Behaviour Scale. The structural equation model and bootstrap test examined the mediating role of psychological capital between authentic leadership and innovative behaviour. RESULTS: 3495 Chinese nurses from 37 Anhui Province hospitals participated in this study. The mean item score of authentic leadership was 3.25 (SD 0.83), psychological capital was 4.85 (SD 0.89), and innovative behaviour was 2.82 (SD 0.84). Authentic leadership perceived by nurses, psychological capital, and innovative behaviour were statistically significant and positively correlated with each other (r = 0.524 ~ 0.806, p < 0.01). Psychological capital significantly mediated the association between authentic leadership and innovative behaviour (ß = 0.449, p < 0.001), and its mediating effect accounted for 76.75% of the total effect. CONCLUSION: Results suggest the importance of developing nurse managers' authentic leadership to foster nurses' psychological capital and innovation behaviour.


Asunto(s)
Liderazgo , Enfermeras Administradoras , Humanos , Pueblo Asiatico , Estudios Transversales , Hospitales
11.
Nurse Educ Pract ; 75: 103907, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38308947

RESUMEN

AIM: To systematically evaluate the effect of smoking cessation training on nursing students' learning outcomes. DESIGN: This systematic review followed the PRISMA guidelines and was registered with PROSPERO (CRD42022373280). METHODS: Ten electronic English and Chinese databases were searched to identify articles on nursing students' smoking cessation training from inception to October 2022. Medical Education Research Study Quality Instrument was used to assess the methodological quality of eligible studies. RESULTS: Twelve moderate methodological quality studies (three randomized controlled trials and nine quasi-experimental studies) with 2114 undergraduate nursing students were included. Teaching strategies included didactic lectures, collaborative learning, blended learning and the service-learning approach. Eight studies showed that the training significantly increased nursing students' knowledge of smoking cessation (p < 0.05) and three of them showed a large effect size (Cohen's d: 0.83-1.31). Seven studies showed that training enhanced students' attitudes/motivation towards smoking cessation interventions significantly (p < 0.05) and two of them showed a large effect size (Cohen's d: 1.11-1.84). Nine studies reported that students' self-efficacy improved significantly after training (p < 0.05) and six of them showed a large effect size (Cohen's d: 0.98-2.18). Two one-group pre-post studies showed training significantly improved students' practice of 5 A's behavior (p < 0.05), with a small effect size (Cohen's d < 0.50). CONCLUSIONS: This review showed that smoking cessation training had a positive and large effect on undergraduate nursing students' knowledge, attitudes/motivation and self-efficacy towards smoking cessation intervention, but the effect of changing the practice of 5 A's was modest. We noted that very few RCTs were done and most studies only used subjective measures. More robust experimental studies with long-term follow-up are warranted in evaluating nursing students' practice/behavior of smoking cessation intervention and patients' quitting outcomes. Blended and collaborative learning are recommended in smoking cessation education.


Asunto(s)
Bachillerato en Enfermería , Cese del Hábito de Fumar , Estudiantes de Enfermería , Humanos , Estudiantes de Enfermería/psicología , Estudiantes de Enfermería/estadística & datos numéricos , Aprendizaje , Autoeficacia
12.
Foods ; 13(4)2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38397567

RESUMEN

BACKGROUND: Hyperuricaemia (HUA) is a disorder of purine metabolism in the body. We previously synthesized a hesperitin (Hsp)-Cu(II) complex and found that the complex possessed strong uric acid (UA)-reducing activity in vitro. In this study we further explored the complex's UA-lowering and nephroprotective effects in vivo. METHODS: A mouse with HUA was used to investigate the complex's hypouricemic and nephroprotective effects via biochemical analysis, RT-PCR, and Western blot. RESULTS: Hsp-Cu(II) complex markedly decreased the serum UA level and restored kidney tissue damage to normal in HUA mice. Meanwhile, the complex inhibited liver adenosine deaminase (ADA) and xanthine oxidase (XO) activities to reduce UA synthesis and modulated the protein expression of urate transporters to promote UA excretion. Hsp-Cu(II) treatment significantly suppressed oxidative stress and inflammatory in the kidney, reduced the contents of cytokines and inhibited the activation of the nucleotide-binding oligomerization domain (NOD)-like receptor thermal protein domain associated protein 3 (NLRP3) inflammatory pathway. CONCLUSIONS: Hsp-Cu(II) complex reduced serum UA and protected kidneys from renal inflammatory damage and oxidative stress by modulating the NLRP3 pathway. Hsp-Cu(II) complex may be a promising dietary supplement or nutraceutical for the therapy of hyperuricemia.

13.
Food Chem ; 439: 138075, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38029565

RESUMEN

This study reported oleogel-based emulsions (OGEs, W/O) stabilized by carnauba wax. The effects of different external factors (heating temperature, crystallization temperature, and shear application during crystallization) on the microstructure and linear/nonlinear rheological properties of OGEs were investigated. Microstructural observation suggested that the OGEs had a uniform droplet distribution, and the carnauba wax crystals trapped oil in the continuous phase. The gelatinized oil phase allowed the OGEs to have a solid appearance and typical yielding behavior. The small amplitude oscillation shear analysis showed that lower heating temperature, higher crystallization temperature, and suitable shear application resulted in a stronger, more stable, and tighter packed network structure and better resistance to deformation of the OGEs. For nonlinear behavior, the elastic dominant behavior of OGEs transformed into viscous dominant behavior at large strain amplitudes, accompanied by more energy dissipation, strain stiffening, and a transition from shear thickening to shear thinning.


Asunto(s)
Calor , Compuestos Orgánicos , Emulsiones/química , Compuestos Orgánicos/química , Temperatura , Reología
14.
Enzyme Microb Technol ; 173: 110355, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38041880

RESUMEN

Due to the increasing demand for health-conscious and environmentally friendly products, D-mannose has gained significant attention as a natural, low-calorie sweetener. The use of D-mannose isomerases (D-MIases) for D-mannose production has emerged as a prominent area of research, offering superior advantages compared with conventional methods such as plant extraction and chemical synthesis. In this study, a gene encoding D-MIase was cloned from Bifidobacterium and expressed in E. coli BL21 (DE3). The heterologously expressed enzyme, Bifi-mannose, formed a trimer with a molecular weight of 146.3 kDa and a melting temperature (Tm) of 63.39 ± 1.3 °C. Bifi-mannose exhibited optimal catalytic activity at pH 7.5 and 55 °C, and retained more than 80% of its activity after a 3-hour incubation at 55 °C, demonstrating excellent thermal stability. The Km, Vmax, and kcat/Km values of Bifi-mannose for D-fructose isomerization were determined as 538.7 ± 62.5 mM, 11.7 ± 0.9 µmol·mg1·s1, and 1.02 ± 0.3 mM1·s1, respectively. Notably, under optimized conditions, catalytic yields of 29.4, 87.1, and 148.5 mg·mL1 were achieved when using 100, 300, and 500 mg·mL1 of D-fructose as substrates, resulting in a high conversion rate (29%). Furthermore, kinetic parameters and molecular docking studies revealed that His387 residue primarily participates in the opening of the pyranose ring, while His253 acts as a basic catalyst in the isomerization process.


Asunto(s)
Isomerasas Aldosa-Cetosa , Bifidobacterium bifidum , Manosa , Escherichia coli/metabolismo , Bifidobacterium bifidum/genética , Bifidobacterium bifidum/metabolismo , Simulación del Acoplamiento Molecular , Isomerasas Aldosa-Cetosa/metabolismo , Fructosa , Temperatura , Concentración de Iones de Hidrógeno , Cinética , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Clonación Molecular
15.
BMC Nurs ; 22(1): 441, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37993929

RESUMEN

BACKGROUND: Caring behavior among nurses would have an impact on patient outcomes. External organizational job resources and personal internal psychological resources are correlated to nurses' caring behavior. Authentic leadership and psychological capital were shown to be correlated with nurses' caring behavior in previous studies. However, the relationships among the three are nevertheless unclear. This study aimed to examine if psychological capital could act as a mediator between nursing managers' authentic leadership and nurses' caring behavior. METHODS: In December 2021, a total of 3,662 nurses were recruited from 37 hospitals in Anhui Province, China. They filled out online surveys, including general demographic information, the Authentic Leadership Questionnaire, the Psychological Capital Questionnaire, and the Caring Behavior Inventory. Structural Equation Modeling and the bootstrapping procedure were used to examine the mediating role of psychological capital. RESULTS: The scores of authentic leadership, psychological capital, and caring behavior of 3,495 nurses were 52.04 ± 13.24, 96.89 ± 17.78, and 104.28 ± 17.01, respectively. Psychological capital significantly mediated the relationship between authentic leadership and nurses' caring behavior (ß = 0.378, p < 0.001, 95% confidence interval: 0.350 ~ 0.402), which made up 78.75% of the total impact (0.480). CONCLUSION: The findings of this study suggested that nursing managers should develop an authentic leadership style, which can effectively improve nurses' caring behaviors toward patients in clinical practice. Meanwhile, nursing leaders should strengthen nurses' psychological evaluation and training, and promote nurses' caring behavior in clinical settings.

16.
Int J Biol Macromol ; 252: 126415, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37598817

RESUMEN

The activation of toll-like receptor 4 (TLR4) signaling is crucial for initiating and coordinating the immune response against infections, and is proved as a vital target for inflammatory diseases. Herein, TLR4 with sufficient amount and functional activity was generated by heterologous expression and used to investigate the mechanism of apigenin (Api)/chrysin (Chr) inhibition of TLR4 activation. The results demonstrated that Api/Chr exhibited a strong fluorescence quenching effect through a static quenching and a high binding affinity (Ka > 105 L·mol-1) with TLR4, indicating the potential of Api/Chr as a TLR4 inhibitor. Additionally, the binding of Api/Chr induced a loose and unstable conformation of TLR4 with evidence like the decreased hydrophobicity of the tryptophan microenvironment, decreased α-helix content and increased free sulfhydryl content, resulting in reduced stability of the TLR4. The computer simulations revealed that Api/Chr occupied the myeloid differentiation factor 2 (MD-2) binding region, preventing MD-2 from binding to TLR4. Furthermore, the accuracy of the binding site between Api/Chr and TLR4 was confirmed through genetic mutations. Overall, the mechanism by which Api/Chr inhibited TLR4 activation was elucidated at the macroscopic and molecular levels, providing the worthful information concerning the future therapeutic application of Api/Chr as a natural TLR4 inhibitor.


Asunto(s)
Apigenina , Receptor Toll-Like 4 , Receptor Toll-Like 4/metabolismo , Apigenina/farmacología , Transducción de Señal , Flavonoides/farmacología , Lipopolisacáridos/farmacología
17.
Foods ; 12(14)2023 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-37509901

RESUMEN

The bioactivity and gastrointestinal stability of epicatechin gallate (ECG) may be affected by processing conditions. Results showed that the antioxidant ability and inhibitory activity on xanthine oxidase (XO) of ECG were higher at low pH values. Appropriate microwave and heating treatments improved the antioxidant (the scavenging rate increased from 71.75% to 92.71% and 80.88% under the microwave and heating treatments) and XO inhibitory activity (the inhibitory rate increased from 47.11% to 56.89% and 51.85% at the microwave and heating treatments) of ECG. The treated ECG led to a more compact structure of XO. Moreover, there may be synergistic antioxidant and inhibitory effects between ECG and its degradation products. The bioaccessibility of ECG after simulated digestion was untreated > microwave > heating, and the microwave-treated ECG still had good XO inhibitory activity after digestion. These findings may provide some significant information for the development of functional foods enriched in catechins.

18.
Food Res Int ; 170: 113000, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37316070

RESUMEN

This study aimed to explore the impacts of gallic acid (GA)/protocatechuic acid (PA) on the structural and functional characteristics of whey proteins (WP) through covalent binding. To this purpose, the covalent complexes of WP-PA and WP-GA at different concentration gradients were prepared by the alkaline method. SDS-PAGE indicated that PA/GA was cross-linked by covalent bonds. The decreased contents of free amino and sulfhydryl groups suggested that WP formed covalent bonds with PA/GA by amino and sulfhydryl groups, and the structure of WP became slightly looser after covalent modification by PA/GA. When the concentration of GA was added up to 10 mM, the structure of WP was slightly loosened with a reduction of α-helix content by 2.3% and an increase in random coil content by 3.0%. The emulsion stability index of WP increased by 14.9 min after interaction with GA. Moreover, the binding of WP and 2-10 mM PA/GA increased the denaturation temperature by 1.95 to 19.87 °C, indicating the improved thermal stability of the PA/GA-WP covalent complex. Additionally, the antioxidant capacity of WP was increased with increasing GA/PA concentration. This work may offer worthful information for enhancing the functional properties of WP and the application of the PA/GA-WP covalent complexes in food emulsifiers.


Asunto(s)
Ácido Gálico , Hidroxibenzoatos , Proteína de Suero de Leche , Emulsiones
19.
Food Chem ; 422: 136248, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37126957

RESUMEN

The mechanism of epigallocatechin gallate (EGCG)-modified ovalbumin gel (EMOG) was investigated. Results indicated that, with the increase of EGCG concentration from 0% to 0.05%, the opacity, hardness, and cohesiveness of EMOG increased significantly from 0.058 to 0.133, 321.0 g to 377.6 g, and 0.879 to 0.951, respectively, while the soluble protein, surface hydrophobicity, and free sulfhydryl decreased significantly by 41.74%, 28.26%, and 39.36%, respectively. Moreover, EGCG promoted the formation of dense and stable microstructures of EMOG, changed the expansion rate, and improved the stability of EMOG. Moreover, the results of silico simulation showed that EGCG would insert into ovalbumin and interact with the amino acids through van der Waals force and hydrogen bonds, leading to a compact and stable protein structure. In this paper, the mechanism of modification of ovalbumin by EGCG was elucidated at the macro and micro levels, providing insights into the action of polyphenols and proteins.


Asunto(s)
Catequina , Agregado de Proteínas , Ovalbúmina , Hidrógeno , Simulación por Computador , Catequina/química
20.
Ultrason Sonochem ; 97: 106442, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37244085

RESUMEN

In this study, the effects of ultrasound treatment on the texture, physicochemical properties and protein structure of composite gels prepared by salted egg white (SEW) and cooked soybean protein isolate (CSPI) at different ratios were investigated. With the increased SEW addition, the ζ-potential absolute values, soluble protein content, surface hydrophobicity and swelling ratio of composite gels showed overall declining trends (P < 0.05), while the free sulfhydryl (SH) contents and hardness of exhibited overall increasing trends (P < 0.05). Microstructural results revealed that composite gels exhibited denser structure with the increased SEW addition. After ultrasound treatment, the particle size of composite protein solutions significantly decreased (P < 0.05), and the free SH contents of ultrasound-treated composite gels were lower than that of untreated composite gels. Moreover, ultrasound treatment enhanced the hardness of composite gels, and promoted the conversion of free water into non-flowable water. However, when ultrasonic power exceeded 150 W, the hardness of composite gels could not be further enhanced. FTIR results indicated that ultrasound treatment facilitated the composite protein aggregates to form a more stable gel structure. The improvement of ultrasound treatment on the properties of composite gels was mainly by promoting the dissociation of protein aggregates, and the dissociated protein particles further interacted to form denser aggregates through disulfide bond, thus facilitating the crosslinking and reaggregation of protein aggregates to form denser gel structure. Overall, ultrasound treatment is an effective approach to improve the properties of SEW-CSPI composite gels, which can improve the potential utilization of SEW and SPI in food processing.


Asunto(s)
Clara de Huevo , Proteínas de Soja , Proteínas de Soja/química , Agregado de Proteínas , Culinaria , Geles/química , Cloruro de Sodio , Agua/química , Compuestos de Sulfhidrilo
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