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1.
Langmuir ; 39(49): 17782-17797, 2023 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-38033267

RESUMO

Myofibrillar protein (MP) aggregate models have been established to elucidate the correlation between their aggregate sizes and interfacial properties. The interfacial layer thickness was measured by the polystyrene latex method and quartz crystal microbalance with dissipation measurement. Interfacial conformations were then characterized in situ (front-surface fluorescence spectroscopy) and ex situ (reactive sulfhydryl group and secondary structure measurement following MP displacement). The viscoelasticity of the interfacial film and its resistance to surfactant-induced competitive displacement were reflected by the dilatational rheology and dynamic interfacial tension with the bulk phase exchange. Finally, we compared the findings of competitive displacement before/after adding a sulfhydryl-blocking agent, N-ethylmaleimide, to highlight the role of S-S linkage on interfacial film formation and stability. We substantiated that the aggregate size of the MP governed their interfacial properties. Small-sized aggregates exhibited more ordered secondary structures on the oil-water interface, which was conducive to the adsorption ratio of the protein and the adsorption dynamics. Although larger aggregates lowered the diffusion rate during interfacial film formation, they allowed the thicker and more viscoelastic interfacial film to be constructed afterward through more disulfide bond formation, resulting in greater resistance to surfactant-induced competitive displacement.


Assuntos
Proteínas , Surfactantes Pulmonares , Tensão Superficial , Tensoativos/química , Adsorção , Dissulfetos
2.
Crit Rev Food Sci Nutr ; : 1-15, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37183695

RESUMO

Myofibrillar proteins (MPs), the most important proteins in muscle, play a vital role in the texture, flavor, sensory and consumer acceptance of final muscle-based food products. Over the past several decades, conjugation of carbohydrates to MPs via glycosylation is of particular interest due to the substantial enhancement in MPs characteristics. Studying the covalent interactions between carbohydrates and MPs under various processing conditions and molecular mechanisms by which carbohydrates affect the functionalities of MPs can introduce new perspectives for design and production of muscle-based foods. However, there is no insightful and comprehensive summary of the structural, physicochemical and functional characteristics changes of MPs induced by glycosylation modification and how these changes can be adopted to potentially promote the science-based development of tailor-made muscle foods. Based on this, the functionalities of MPs as well as their practical limiting issues are initially highlighted. A comprehensive overview of fabrication strategies is then introduced. Additionally, changes in the structural and functional properties of MPs regulated by glycosylation have also been carefully summarized. On this basis, the research limitations to be solved and our perspectives for the future development of muscle-based foods are put forward.

3.
Int J Mol Sci ; 24(9)2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-37175820

RESUMO

Sanguinarine (1) is a natural product with significant pharmacological effects. However, the application of sanguinarine has been limited due to its toxic side effects and a lack of clarity regarding its molecular mechanisms. To reduce the toxic side effects of sanguinarine, its cyanide derivative (1a) was first designed and synthesized in our previous research. In this study, we confirmed that 1a presents lower toxicity than sanguinarine but shows comparable anti-leukemia activity. Further biological studies using RNA-seq, lentiviral transfection, Western blotting, and flow cytometry analysis first revealed that both compounds 1 and 1a inhibited the proliferation and induced the apoptosis of leukemic cells by regulating the transcription of c-MET and then suppressing downstream pathways, including the MAPK, PI3K/AKT and JAK/STAT pathways. Collectively, the data indicate that 1a, as a potential anti-leukemia lead compound regulating c-MET transcription, exhibits better safety than 1 while maintaining cytostatic activity through the same mechanism as 1.


Assuntos
Citostáticos , Leucemia Eritroblástica Aguda , Leucemia , Humanos , Citostáticos/farmacologia , Leucemia Eritroblástica Aguda/tratamento farmacológico , Fosfatidilinositol 3-Quinases/metabolismo , Cianetos , Apoptose , Leucemia/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Linhagem Celular Tumoral
4.
J Sci Food Agric ; 103(6): 3118-3128, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36268675

RESUMO

BACKGROUND: Novel thermo-reversible hydrogels that undergo gelation in feedback to external stimuli have numerous applications in the food, biomedical, and functional materials fields. Muscle myofibrillar protein (MP) has long been known for thermally irreversible gelation. Once the reversible gelation of MP is achieved, its scope for research and application will expand. RESULTS: The work reported here achieved, for the first time, a thermo-reversible MP gelation by elaborate deamidation using protein glutaminase (PG). The protein concentration and PG reaction time within windows of 1.0-2.5% and 8 h or 12 h were observed to be vital for creating thermo-reversible gels. The gel strength increased with protein concentration. The gel displayed a perforated lamellar microstructure, which resulted in a high water-holding capacity. The rheological results revealed the thermo-reversibility of the gel was robust for up to five cycles of heating and cooling. The thermally reversible gelation is closely related to the reversible assembly between individual α-helix and helical coiled coil. Hydrophobic interactions proved to be predominantly involved in the formation and stabilization of the gel network structure. CONCLUSION: This work increases the scope of research into the thermo-responsive behavior of MP-based gel. It can foster advances in research into the applications of muscle proteins and into the use of PG as a novel ingredient in the food industry. © 2022 Society of Chemical Industry.


Assuntos
Glutaminase , Proteínas Musculares , Géis/química , Proteínas Musculares/química , Hidrogéis/química , Alimentos , Reologia
5.
J Sci Food Agric ; 103(5): 2473-2482, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36658470

RESUMO

BACKGROUND: Myosin is the most important component of myofibrillar protein, with excellent gelling properties. To date, heating treatment remains the mainstream method for forming gel in meat products, and it has the most extensive application in the field of meat industry. However, at present, there are few reports on the effects of heating rates on myosin self-assembly and aggregation behavior during heating treatment. RESULTS: The present study aimed to investigate the effects of different heating rates (1, 2, 3 and 5 °C min-1 ) on the self-assembly behavior, physicochemical, structural and gelling properties of myosin. At the lowest heating rate of 1 °C min-1 , the myosin gel had a dense microstructure, the highest elastic modulus (G') and water holding capacity compared to higher heating rates (2, 3 and 5 °C min-1 ). At higher temperatures (40, 45 °C), the surface hydrophobicity, turbidity, particle size distribution and self-assembly behavior of myosin in pre-gelling solutions showed that myosin had sufficient time to denature, underwent full structure unfolding before aggregation at the heating rate of 1°C min-1 , and formed regular and homogeneous spherical aggregates. Therefore, the myosin gel also had a better three-dimensional network. CONCLUSION: The heating rates had an important effect on the quality of myosin gels, and had theoretical implications for improving the quality of meat gel products. © 2023 Society of Chemical Industry.


Assuntos
Calefação , Miosinas , Animais , Bovinos , Miosinas/química , Temperatura Alta , Interações Hidrofóbicas e Hidrofílicas , Géis/química
6.
Crit Rev Food Sci Nutr ; : 1-21, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36239319

RESUMO

As living standards rise, the demand for high-quality chilled meat among consumers also grows. Researchers and enterprises have been interested in ensuring the quality of chilled meat in all links of the downstream industry. Nanozyme has shown the potential to address the aforementioned requirements. Reasons and approaches for the application of nanozymes in the freshness assessment or shelf life extension of chilled meat were discussed. The challenges for applying these nanozymes to ensure the quality of chilled meat were also summarized. Finally, this review examined the safety, regulatory status, and consumer attitudes toward nanozymes. This review revealed that the freshness assessment of chilled meat is closely related to mimicking the enzyme activities of nanozymes, whereas the shelf life changes of chilled meat are mostly dependent on the photothermal activities and pseudophotodynamic activities of nanozymes. In contrast, studies regarding the shelf life of chilled meat are more challenging to develop, as excessive heat or reactive oxygen species impair its quality. Notably, meat contains a complex matrix composition that may interact with the nanozyme, reducing its effectiveness. Nanopollution and mass manufacturing are additional obstacles that must be overcome. Therefore, it is vital to choose suitable approaches to ensure meat quality. Furthermore, the safety of nanozymes in meat applications still needs careful consideration owing to their widespread usage.

7.
Molecules ; 27(12)2022 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-35745057

RESUMO

Thirty-three benzophenanthridine alkaloid derivatives (1a-1u and 2a-2l) were synthesized, and their cytotoxic activities against two leukemia cell lines (Jurkat Clone E6-1 and THP-1) were evaluated in vitro using a Cell Counting Kit-8 (CCK-8) assay. Nine of these derivatives (1i-l, 2a, and 2i-l) with IC50 values in the range of 0.18-7.94 µM showed significant inhibitory effects on the proliferation of both cancer cell lines. Analysis of the primary structure-activity relationships revealed that different substituent groups at the C-6 position might have an effect on the antileukemia activity of the corresponding compounds. In addition, the groups at the C-7 and C-8 positions could influence the antileukemia activity. Among these compounds, 2j showed the strongest in vitro antiproliferative activity against Jurkat Clone E6-1 and THP-1 cells with good IC50 values (0.52 ± 0.03 µM and 0.48 ± 0.03 µM, respectively), slightly induced apoptosis, and arrested the cell-cycle, all of which suggests that compound 2j may represent a potentially useful start point to undergo further optimization toward a lead compound.


Assuntos
Alcaloides , Antineoplásicos , Alcaloides/farmacologia , Antineoplásicos/farmacologia , Apoptose , Benzofenantridinas/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Estrutura Molecular , Relação Estrutura-Atividade
8.
J Sci Food Agric ; 101(1): 279-286, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32623748

RESUMO

BACKGROUND: Wooden breast (WB) myopathy in broiler chickens is a growing challenge for the poultry industry. Previous multi-omic data have implied that the pathogenesis of WB is associated with the activation of immune system and inflammatory response. However, the intricate mechanisms are not fully understood. This study was therefore conducted to systematically investigate the morphology, expression of cytokines as well as the underlying signaling pathways regulating the inflammatory response in pectoralis major (PM) muscle of WB myopathic broilers. RESULTS: wHistopathological changes, increased plasma creatine kinase and lactate dehydrogenase activities, elevated myeloperoxidase activity and overproduction of nitric oxide in muscle indicated the enhancement of muscle damage and inflammation in WB broilers. The messenger RNA (mRNA) expressions of inflammatory cytokines were dysregulated in PM muscle and contents of interleukin (IL)-1ß, IL-8 and tumor necrosis factor-α were increased in serum of WB myopathic broilers, indicating this myopathy was associated with immune disorder and systemic inflammation response. Additionally, toll-like receptor (TLR) levels were upregulated, the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway was activated and the mRNA expression levels of downstream inflammatory mediators were enhanced in PM muscle of WB myopathy affected birds. CONCLUSION: The results indicated an immune disorder and a systemic inflammation response in WB myopathic broilers, which might be related to a synergetic effect of TLRs and NF-κB pathway. © 2020 Society of Chemical Industry.


Assuntos
Citocinas/genética , Doenças Musculares/veterinária , Doenças das Aves Domésticas/genética , Animais , Galinhas , Citocinas/imunologia , Interleucina-8/genética , Interleucina-8/imunologia , Masculino , Doenças Musculares/genética , Doenças Musculares/imunologia , NF-kappa B/genética , NF-kappa B/imunologia , Doenças das Aves Domésticas/imunologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Regulação para Cima
9.
Compr Rev Food Sci Food Saf ; 20(1): 458-500, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33443791

RESUMO

Today, both consumers and food industry producers have exhibited an ever-growing interest in improving and broadening the functional performance of proteins in food industry. Myofibrillar protein (MP) is mainly responsible for texture, yield and organoleptic characteristics of final meat products. To increase functional properties of MP, technological and nutritional improvement of MP is needed to modify its structure and functionalities. Considerable approaches, including additives, oxidation treatments, and novel food processing technologies, have been utilized to modify its functional properties to manufacture acceptable meat products with lower cost and more desirable nutritional characteristics. However, a comprehensive summary of structural and functional changes of MP in response to different modification strategies is still lacking. Hence, in this review paper, our main goal is first to provide an overview of the functional characteristics of MP. Then, this review will mainly discuss the current knowledge on the functional changes of MP caused by various modification methods and will present some examples of previous works and recent progress. Finally, future outlooks are presented to tailor the manufacture of functionality enhanced and value-added muscle-based products and enable modified MP can be applied as a novel meat ingredient in food industry.


Assuntos
Produtos da Carne , Proteínas Musculares , Manipulação de Alimentos , Carne , Produtos da Carne/análise , Oxirredução
10.
Compr Rev Food Sci Food Saf ; 20(1): 924-959, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33340260

RESUMO

To improve the quality of meat products is a constant focus for both the meat industry and scientists. As major components in meat protein, the gelation properties of myofibrillar proteins (MPs) predominantly determine the sensory quality and product yield of the final product. Naturally or artificially occurring covalent modifications are known to largely affect MP functionality by changing the protein structure and forming aggregates, leading to both favorable and unfavorable outcomes. The review aims to summarize the mechanisms associated with several covalent modifications and the recent developments in enhancing MP gelation properties. Various extrinsic and intrinsic parameters controlling oxidation, phenolic-protein interactions, enzyme catalysis, glycation, and isoelectric solubilization/precipitation, and their effects on the characteristics of heat-induced MP gels are discussed. This article provides an improved understanding of the covalent modifications that occur mainly in the MP system and how they can be utilized to promote its gelation properties. Covalent modifications exhibited dose-dependent and dual-role manners for MP gelation properties. Mild oxidation, enzyme catalysis, and isoelectric solubilization/precipitation treatment would be beneficial to form more aligned and cross-linked three-dimensional networks for MP gels because of moderate protein aggregation. However, an excessive aggregate impedes the MP gelation behavior, leading to reduced gelation quality. Glycation effectively increased hydrophilicity of MPs and phenolic conjugation provides MPs with novel bioactivity. A proper utilization of such a process or even a rational combination of them allowed us to enhance the gelation properties of MP with assorted appreciated functionalities and further improve the quality of meat products.


Assuntos
Produtos da Carne , Carne , Géis , Carne/análise , Proteínas Musculares , Oxirredução
11.
Food Microbiol ; 82: 89-98, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31027824

RESUMO

Pseudomonas spp. have emerged as the main spoilage bacteria, with many strains easily forming biofilms on food-contact surfaces and causing cross-contamination. The efficacy of disinfectants against bacteria is usually tested with planktonic cells; however, the disinfection tolerance of biofilms, especially detached biofilms, remains unknown. Here, we investigated the tolerance responses of detached and adhered biofilms of Pseudomonas fluorescens to acidic electrolyzed water (AEW) by determining tolerance responses by plate counting, comparing them using a Weibull model, and verifying changes in bacterial morphology by scanning electron microscopy. The experimental data and the responses calculated using Weibull a (scale) and b (shape) parameters agreed well (R2 values: 0.974-0.999), and we found that AEW exhibited effective antimicrobial activity against P. fluorescens, with adhered biofilms were more resistant than detached biofilms and planktonic cells. Additionally, AEW increased the bacterial membrane permeability and decreased the membrane potential, intracellular ATP concentrations, and intracellular pH while also triggering the disruption of extracellular polymeric substances. These results demonstrated that the morphophysiological responses of detached and adhered biofilms differed significantly and provided information on disinfectant-resistance strategies potentially beneficial to the development of novel disinfection approaches.


Assuntos
Biofilmes/efeitos dos fármacos , Desinfetantes/farmacologia , Eletrólise , Pseudomonas fluorescens/efeitos dos fármacos , Água/farmacologia , Ácidos/química , Permeabilidade da Membrana Celular , Contagem de Colônia Microbiana , Desinfecção/métodos , Potenciais da Membrana/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Pseudomonas fluorescens/fisiologia , Água/química
12.
J Sci Food Agric ; 99(14): 6209-6218, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31250450

RESUMO

BACKGROUND: Heat treatment induces both structural and digestive change of meat protein. However, little has been revealed regarding the associations between structural changes and digested peptides of myofibrillar proteins. This work investigated the effects of heat treatment on the structures and in vitro digestibility of actomyosin, and the peptidomics of the digests were analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS). RESULTS: Heat treatment resulted in unfolding and aggregation behavior of actomyosin according to the results of surface hydrophobicity and particle size. Formation of disulfide bonds and increase in carbonyl groups that occurred during heat treatment of actomyosin indicated the oxidation of specific residues. Unfolding behavior could elevate digestibility of actomyosin by exposing residues, based on the identification of peptides in digests of actomyosin using LC-MS/MS. However, the disulfide bond proved to reduce the action of digestive proteases, since the peptides number (increased from 56 to 86 in sample heated at 70 °C for 30 min) and peptides intensity in digests largely increased after the addition of dithiothreitol (DTT). Heating at higher temperature (100 °C) induced severer aggregation and oxidation, which resulted in lower digestibility of actomyosin than that heated at 70 °C by burying or damaging partial cleavage sites for digestive proteases. CONCLUSIONS: This work highlights the huge influence of heat treatment on the multi-scale structures of myofibrillar proteins, which largely changed the peptides composition in protein digests. © 2019 Society of Chemical Industry.


Assuntos
Actomiosina/química , Actomiosina/metabolismo , Animais , Cromatografia Líquida , Digestão , Temperatura Alta , Interações Hidrofóbicas e Hidrofílicas , Oxirredução , Peptídeos/química , Peptídeos/metabolismo , Suínos , Espectrometria de Massas em Tandem
13.
Compr Rev Food Sci Food Saf ; 18(2): 380-401, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33336942

RESUMO

Stress inevitably occurs from the farm to abattoir in modern livestock husbandry. The effects of stress on the behavioral and physiological status and ultimate meat quality have been well documented. However, reports on the mechanism of stress effects on physiological and biochemical changes and their consequent effects on meat quality attributes have been somewhat disjointed and limited. Furthermore, the causes of variability in meat quality traits among different animal species, muscle fibers within an animal, and even positions within a piece of meat in response to stress are still not entirely clear. This review 1st summarizes the primary stress factors, including heat stress, preslaughter handling stress, oxidative stress, and other stress factors affecting animal welfare; carcass quality; and eating quality. This review further delineates potential stress-induced pathways or mediators, including AMP-activated protein kinase-mediated energy metabolism, crosstalk among calcium signaling pathways and reactive oxygen species, protein modification, apoptosis, calpain and cathepsin proteolytic systems, and heat shock proteins that exert effects that cause biochemical changes during the early postmortem period and affect the subsequent meat quality. To obtain meat of high quality, further studies are needed to unravel the intricate mechanisms involving the aforementioned signaling pathways or mediators and their crosstalk.

14.
Langmuir ; 34(30): 8848-8856, 2018 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-29945444

RESUMO

Protein conformational rearrangement triggered by adsorption to the hydrophobic interface of oil droplets has long been considered as a key factor in emulsification. In this study, an alkaline pH-shifting-driven conformational adaptation enhanced interfacial proteins was used to improve their stability against heat-induced flocculation of myosin emulsions. We used the unfolded myosin at pH 12 to emulsify soy oil and then readjusted the pH of the emulsion to neutral. The corresponding myosin emulsion (0.5% w/v protein, 10% v/v soy oil, and 0.6 M NaCl) almost not flocculated when heated at 75 °C for 30 min. Moreover, after thermal treatment, the particle size of the emulsion was not significantly increased ( P > 0.05) and the emulsion did not exhibit a creaming phenomenon after a week. Based on the circular dichroism and Fourier transform infrared analysis, we speculated the superiority of the emulsion is closely related to the alkaline pH-shifting-driven conformational adaptation enhanced interfacial protein. Additionally, the resulting steric stabilization in overcoming the attractive hydrophobic forces between denatured protein molecules coated droplets might be the main factor for the inhibition of heat-induced flocculation of the emulsion. Our research may have important implications for the formulation of protein-stabilized oil-in-water emulsions.


Assuntos
Emulsões , Temperatura Alta , Miosinas , Emulsões/química , Floculação , Concentração de Íons de Hidrogênio , Miosinas/química , Estabilidade Proteica
15.
Crit Rev Food Sci Nutr ; 58(17): 2981-3003, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28678522

RESUMO

The texture, yield, and organoleptic properties of comminuted meat products are closely related to the structure and functionality of myofibrillar proteins (MP). To enhance functional properties of MP, high hydrostatic pressure (HHP) has been widely utilized to modify the structure of MP through protein denaturation, solubilization, aggregation or gelation. This modification depends on the protein system (specie, type and formulation) and HHP condition (pressure intensity, pressurizing gradient, duration time, temperature, pressure/temperature and the sequence of application). However, there remains a lack of a systematic summary of structural changes and structure-function relationship of MP in response to various HHP conditions. Hence, this review first explored the profound knowledge on the structural and functional changes of MP induced by HHP based on previous works and recent progress. Second, to meet the growing demand for economical, nutritional and healthy meat products, recent applications of HHP on the manufacture of low salt, low phosphate and/or low fat gel-type meat products, as well as value-added and texture-modified meat products were highlighted. Finally, future considerations were presented to facilitate progress in this area and to enable HHP as an efficient strategy in tailoring the manufacture of functionally improved, value-added and healthy muscle gelled foods.


Assuntos
Proteínas Alimentares , Manipulação de Alimentos , Produtos da Carne , Proteínas Musculares/química , Animais , Alimentos Especializados , Humanos , Pressão Hidrostática
16.
Food Microbiol ; 76: 443-449, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30166172

RESUMO

Modified atmosphere packaging (MAP) is considered an effective method for extending the shelf life of meat. The use of optimal mixture of gases (CO2 and N2) in food packaging containers has been proved to effectively inhibit the growth of microorganisms in poultry meat. In general, a minimum CO2 concentration range of 20%-30% is required for the inhibitory effect. The aim of this study was to investigate the mechanism by which MAP (CO2/N2 30%/70%) inhibits Pseudomonas fragi, a dominant spoilage microorganism in aerobically stored chilled meat. The cell physiological changes were determined by measuring membrane integrity, membrane potential, ATP level, and extracellular proteolytic activity. The results showed that samples stored under MA retained cell membrane integrity, but lost significant membrane potential and ATP synthesis activity. Furthermore, the peptides issued from 2 structural proteins (myosin and actin) were mainly identified in air samples, indicating that these fragments result from bacterial proteolytic activity while MAP inhibited this activity. Overall, the study found that cell metabolism and extracellular protease activity decreased under MAP conditions. This study showed that MAP is an effective food preservation strategy and revealed mechanisms by which MAP inhibits spoilage.


Assuntos
Embalagem de Alimentos/métodos , Carne/microbiologia , Pseudomonas fragi/metabolismo , Trifosfato de Adenosina/análise , Trifosfato de Adenosina/metabolismo , Animais , Dióxido de Carbono/farmacologia , Embalagem de Alimentos/instrumentação , Conservação de Alimentos , Gases/farmacologia , Carne/análise , Nitrogênio/farmacologia , Aves Domésticas , Proteólise , Pseudomonas fragi/efeitos dos fármacos , Pseudomonas fragi/crescimento & desenvolvimento
17.
Ecotoxicol Environ Saf ; 153: 181-187, 2018 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-29433086

RESUMO

Anorexia is a hallmark of animal and human exposed to T-2 toxin, a most poisonous trichothecene mycotoxins contaminating various cereal grains including wheat, corn and barley. Although this adverse effect has been well characterized in several animal species, the underlying mechanisms are unclear. The goal for this study was to elucidate the roles of two gut satiety hormones, glucagon-like peptide-17-36 amide (GLP-1) and cholecystokinin (CCK) in T-2 toxin-evoked anorectic response using a mouse anorexia bioassay. Elevations of plasma GLP-1 and CCK significantly corresponded to anorexia induction by T-2 toxin. Direct administration of exogenous GLP-1 and CCK markedly evoked anorectic responses similar to T-2 toxin. The GLP-1 receptor (GLP-1R) antagonist Exendin9-39 dose-dependently cause attenuation of both GLP-1- and T-2 toxin-induced anorectic responses. Pretreatment with the CCK1 receptor (CCK1R) antagonist SR 27897 and CCK2 receptor (CCK2R) antagonist L-365,260 attenuated anorexia induction by both CCK- and T-2 toxin in a dose dependent manner. Taken together, our findings suggest that both GLP-1 and CCK play contributory roles in T-2 toxin-induced anorexia.


Assuntos
Anorexia/induzido quimicamente , Colecistocinina/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Fragmentos de Peptídeos/sangue , Toxina T-2/toxicidade , Animais , Anorexia/sangue , Colecistocinina/administração & dosagem , Relação Dose-Resposta a Droga , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Peptídeo 1 Semelhante ao Glucagon/administração & dosagem , Camundongos , Camundongos Endogâmicos , Fragmentos de Peptídeos/administração & dosagem
18.
J Sci Food Agric ; 98(9): 3563-3570, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29315583

RESUMO

BACKGROUND: In order to evaluate the effect of cooking temperature on the nutrition quality of dry-cured hams, 60 biceps femoris samples from 16 Jinhua hams were divided into four groups (control, 70, 100 and 120 °C) and cooked for 30 min. Carbonyl content, sulfhydryl groups, surface hydrophobicity, microstructure, protein aggregation and digestibility of myofibrillar proteins were investigated. RESULTS: Cooking promoted carbonylation and decreased sulfhydryl groups in a temperature-dependent way. Scanning electron microscopy and Nile Red revealed that protein aggregation became a main phenomenon at 120 °C; it coincided with surface hydrophobicity. The increased carbonyl content and decreased sulfhydryl groups contributed to the formation of aggregates. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles showed the initial difference in proteolysis rate among four groups. The in vitro digestibility of pepsin and of trypsin and α-chymotrypsin increased from the control to 100 °C and decreased from 100 to 120 °C. CONCLUSION: The increased digestibility could be attributed to the oxidation of proteins and exposing recognition sites of digestive enzymes, while the decreased digestibility was due to the formation of aggregates. Cooking was a main factor that affected the digestibility of Jinhua ham, and cooking at 100 °C could be an ideal way to gain the highest digestibility of Jinhua ham. © 2018 Society of Chemical Industry.


Assuntos
Culinária/métodos , Carne/análise , Proteínas Musculares/metabolismo , Miofibrilas/metabolismo , Suínos , Temperatura , Animais , China , Digestão , Microscopia Eletrônica de Varredura , Proteínas Musculares/química , Agregados Proteicos , Compostos de Sulfidrila/análise
19.
Opt Express ; 25(20): A871-A879, 2017 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-29041298

RESUMO

Injection current, and temperature, dependences of the electroluminescence (EL) spectrum from green InGaN/GaN multiple quantum well (MQW)-based light-emitting diodes (LED) grown on a Si substrate, are investigated over a wide range of injection currents (0.5 µA-350 mA) and temperatures (6-350 K). The results show that an increasing temperature can result in the change of injection current-dependent behavior of the EL spectrum in initial current range. That is, with increasing the injection current in the low current range, the emission process of the MQWs is dominated by filling effect of low-energetic localized states at the low temperature range of around 6 K, and by Coulomb screening of the quantum confinement Stark effect followed by a filling effect of the higher levels of the low-energetic localized states at the intermediate temperature range of around 160 K. However, when the temperature is further raised to the higher temperature range of around 350 K, the emission process of the MQWs in the low current range is dominated by carrier-scattering effect followed by non-radiative recombination process. The aforementioned current-dependent behaviors of the EL spectrum are mainly attributed to the strong localized effect of the green LED, as confirmed by the anomalous temperature dependence of the EL spectrum measured at the low injection current of 5 µA. In addition, the injection current dependence of external quantum efficiency at different temperatures shows that, with increasing temperature from 6 to 350 K, in addition to the enhanced non-radiative recombination, electron overflow becomes more significant, especially in the higher temperature range above 300 K.

20.
Crit Rev Food Sci Nutr ; 57(15): 3260-3280, 2017 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-26647280

RESUMO

The qualitative characteristics of meat products are closely related to the functionality of muscle proteins. Myofibrillar proteins (MPs), comprising approximately 50% of total muscle proteins, are generally considered to be insoluble in solutions of low ionic strength (< 0.2 M), requiring high concentrations of salt (> 0.3 M) for solubilization. These soluble proteins are the ones which determine many functional properties of meat products, including emulsification and thermal gelation. In order to increase the utilization of meat and meat products, many studies have investigated the solubilization of MPs in water or low ionic strength media and determining their functionality. However, there still remains a lack of systematic information on the functional properties of MPs solubilized in this manner. Hence, this review will explore some typical techniques that have been used. The main procedures used for their solubilization, the fundamental principles and their functionalities in water (low ionic strength medium) are comprehensively discussed. In addition, advantages and disadvantages of each technique are summarized. Finally, future considerations are presented to facilitate progress in this new area and to enable water soluble muscle MPs to be utilized as novel meat ingredients in the food industry.


Assuntos
Proteínas Musculares/química , Concentração Osmolar , Carne , Solubilidade , Água/química
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