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1.
Food Chem ; 449: 139305, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38615636

RESUMO

The main objective of this study is to investigate the impact and mechanism of soy lecithin incorporation into the gelatin-cinnamaldehyde emulsion, focusing on how it influences emulsion stability during the electrospinning process. In this work, a cinnamaldehyde/gelatin/soy lecithin (CGS) fiber membrane with excellent antibacterial properties was successfully created. The addition of soy lecithin improves the stability of the emulsion and improves the loading performance and fiber morphology of the CGS fiber membrane. Fourier Transform infrared spectroscopy (FTIR) and urea addition confirmed that soy lecithin may strengthen the interface structure of gelatin in the oil and water phases through hydrogen bonds, thus enhancing the stability of the emulsion in electrospinning. The application tests also revealed that the CGS fiber membrane effectively preserved the sensory quality of beef. This study indicates that the vector construction method can extend the utilization of cinnamaldehyde in food industry.

2.
Int J Biol Macromol ; : 131775, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38657922

RESUMO

Active packaging is a novel technology that utilizes active materials to interact with products and the environment, improving food shelf life. The purpose of this work was to fabricate a multifunctional film using Litsea cubeba essential oil (LC-EO) (1 %, 3 %, 5 %, and 7 %) as the active ingredient and pullulan(P)/tapioca starch (TS) as the carrier material. Adding essential oil improves the films properties, such as barrier ability, anti-oxidant, and antibacterial activity. However, tensile strength (TS) and elongation at break (EAB) were slightly reduced from 28.94 MPa to 11.29 MPa and 15.36 % to 12.19 %. The developed PTS3% films showed the best performance in mechanical properties, especially EAB (14.26 %), WVP (3.26 %) and OP (3.13 %), respectively. The inhibitory zone diameters in the agar-well diffusion test were 18.59 mm for Staphylococcus aureus and 17.32 mm for Escherichia coli. Further study was conducted to compare the preservation effects of film with low-density polyethylene bag (LDPE) on chilled beef. Remarkably, PTS3% film decreased the bacterial population in beef meat while maintaining the pH, color, texture, and TBARS levels within an acceptable range for ten days of storage at 4 °C rather than in a low-density polyethylene bag. The outcomes indicated the potential of PTS3% films in food packaging applications.

3.
Int J Food Microbiol ; 415: 110647, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38422678

RESUMO

Staphylococcus aureus (S. aureus) enterotoxins have aroused great concern to food safety owing to its increased risk of food poisoning. The current research aimed to investigate the anti-virulence mechanisms of phloretin against S. aureus in terms of toxin activity and gene expression. The results indicated that phloretin could effectively inhibit the production of hemolysins and enterotoxins, and its anti-virulence effect was exerted in a concentration-dependent manner. Transcriptome results indicated that phloretin could downregulate the transcription level of majority virulence factors related genes (68 %) of S. aureus, including the quorum sensing-related genes (agrB, agrC, agrA, sspA, splF, splD and others) and bacterial secretion system-related genes (secDF, secY2, and yidC). In addition, it was speculated that phloretin was most likely to bind to the AgrA DNA binding domain, thereby affecting the expression of downstream virulence genes (hla, seb, spa, rot, geh, etc) based on molecular docking. Finally, the application in cooked chicken indicated that phloretin could effectively decrease the content of enterotoxins and improve the storage quality of cooked chicken. These findings not only evidenced the feasible anti-virulence activity of phloretin, but also provided a new strategy to prevent S. aureus food poisoning in cooked meat preservation.


Assuntos
Doenças Transmitidas por Alimentos , Infecções Estafilocócicas , Animais , Staphylococcus aureus , Virulência/genética , Galinhas/microbiologia , Simulação de Acoplamento Molecular , Floretina/farmacologia , Floretina/metabolismo , Enterotoxinas/genética , Enterotoxinas/metabolismo , Infecções Estafilocócicas/microbiologia , Perfilação da Expressão Gênica , Antibacterianos/farmacologia
4.
Int J Biol Macromol ; 263(Pt 2): 130401, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38403230

RESUMO

Listeria monocytogenes (L. monocytogenes) is a foodborne pathogen often found in ready-to-eat (RTE) foods, posing significant threats to human health. In this study, an active film based on cross-linking via Schiff base and electrostatic interaction to inactivate L. monocytogenes on RTE foods was constructed. Zinc-casein hydrolysate chelates (Zn-HCas) was prepared and blended with cationic starch (CSt) to form the substrates of the film. Then, Citral (CI) with excellent antibacterial properties was added to enhance the biological and packaging properties of the film through covalent cross-linking (Schiff base). Based on the zinc ion-activated metalloproteinases produced by L. monocytogenes, the cross-linked film could be disrupted and the release of CI was accelerated. The variation in color, FTIR, and amino group content proved that Schiff base reaction had taken place. Enhanced mechanical properties, barrier properties, thermal stability and antimicrobial activity against L. monocytogenes (exceed 99.99 %) were obtained from the CI/Zn-HCas/CSt film. The application on RTE cheese results demonstrated that the cross-linked film could be employed in active packaging field with the ability in maintaining the original chroma and texture properties of RTE cheese. In summary, the prepared cross-linked film could be used as an active packaging against L. monocytogenes contamination with great potential.


Assuntos
Monoterpenos Acíclicos , Caseínas , Listeria monocytogenes , Produtos da Carne , Humanos , Amido , Embalagem de Alimentos/métodos , Zinco , Bases de Schiff , Microbiologia de Alimentos , Produtos da Carne/microbiologia
5.
Int J Food Microbiol ; 414: 110621, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38341904

RESUMO

The increasing risk of food poisoning caused by Staphylococcus aureus (S. aureus) contamination has aroused great concern about food safety. Eugenol is highly favored due to its broad-spectrum antibacterial activity and non-drug resistance property. The study aimed to reveal the anti-bacterial and anti-virulence mechanisms of eugenol against S. aureus using phosphoproteomics. The results indicated that eugenol could inhibit the phosphorylation levels of enzyme I in the bacterial phosphotransferase system (PTS). Meanwhile, it could also inhibit the phosphorylation levels of key enzymes in bacterial carbon metabolism (such as glucose-6-phosphate isomerase of glycolysis and succinyl-CoA synthetase of tricarboxylic acid cycle), thereby decreasing the content of ATP and accelerating bacterial death. In addition, eugenol could inhibit the phosphorylation of AgrA in the quorum sensing system, thereby inhibiting the expression of agr operons (agrA and agrC) and downstream virulence genes (RNAIII, hla and seb). Finally, the application on beef indicated that eugenol could effectively decrease the content of enterotoxins and improve its storage quality. These findings provide a new way for eugenol to prevent S. aureus contamination and food poisoning in meat products.


Assuntos
Doenças Transmitidas por Alimentos , Produtos da Carne , Infecções Estafilocócicas , Animais , Bovinos , Humanos , Staphylococcus aureus , Virulência , Eugenol/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Percepção de Quorum
6.
Int J Biol Macromol ; 260(Pt 1): 129475, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38262830

RESUMO

`The objective of current research was to encapsulate citrus bergamia essential oil (CBEO) in nanocomplexes composed of sodium caseinate (SC) and peach gum polysaccharide (PG) in various ratios (SC/PG-1:0, 0:1, 1:1, 1:3, and 3:1). The nanocomplexes formed by the combination of SC and PG in a ratio of 1:3 exhibited a zeta potential of -21.36 mV and a PDI of 0.25. The CBEO-loaded SC/PG (1:3) nanocomplexes revealed the maximum encapsulation efficiency (82.47 %) and loading capacity (1.85 %). FTIR also confirmed the secondary structure variations in response to different ratios of CBEO-loaded SC/PG nanocomplexes. In addition, the XRD and fluorescence spectroscopy analysis also revealed structural changes among CBEO nanocomplexes. The thermal capability of CBEO-loaded SC/PG (1:3) nanocomplexes via TGA showed the minimum weight loss among other complexes. SEM and CLSM analysis demonstrated the uniform distribution and spherical morphology of CBEO-loaded SC/PG (1:3) nanocomplexes. The antioxidant activity of free CBEO was significantly improved in CBEO-loaded nanocomplexes. Likewise, the inhibitory activity of CBEO-loaded nanocomplexes exhibited significantly higher antibacterial action against S. aureus and E. coli. The aforementioned perspective suggests that SC/PG nanocomplexes have potent potential to serve as highly effective nanocarriers with a broad spectrum of uses in the pharmaceutical and food sectors.


Assuntos
Citrus , Óleos Voláteis , Prunus persica , Caseínas/química , Escherichia coli , Staphylococcus aureus , Óleos Voláteis/farmacologia , Óleos Voláteis/química
7.
Int J Food Microbiol ; 413: 110581, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38246026

RESUMO

Foodborne diseases caused by Staphylococcus aureus contamination on meat and meat products has gained increasing attention in recent years, while the pathogenicity of S. aureus is mainly attributed to its virulence factors production, which is primarily regulated by quorum sensing (QS) system. Herein, we aimed to uncover the inhibitory effects and mechanisms of citral (CIT) on virulence factors production by S. aureus, and further explore its potential application in pork preservation. Susceptibility test confirmed the antibacterial properties of CIT against S. aureus, the minimal inhibitory concentration (MIC) was 0.25 mg/mL. Treatment with sub-MICs of CIT reduced the hemolytic activity by inhibiting the production of α-hemolysin, and staphylococcal enterotoxins (SEs) production was significantly inhibited by CIT in both culture medium and pork without affecting bacterial growth. Transcriptomic analysis indicated that the differentially expression genes encoding α-hemolysin, SEs, and other virulence factors were down-regulated after treatment with 1/2MIC CIT. Moreover, the genes related to QS including agrA and agrC were also down-regulated, while the global transcriptional regulator sarA was up-regulated. Data here demonstrated that CIT could inhibited S. aureus virulence factors production through disturbing QS systems. In a challenge test, the addition of CIT caused a remarkable inhibition of S. aureus population and delay in lipid oxidation and color change on pork after 15 days incubation at 4 °C. These findings demonstrated that CIT could not only efficiently restrain the production of S. aureus virulence factors by disturbing QS, but also exhibit the potential application on the preservation of meat products.


Assuntos
Monoterpenos Acíclicos , Infecções Estafilocócicas , Staphylococcus aureus , Humanos , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Proteínas Hemolisinas , Proteínas de Bactérias/metabolismo , Enterotoxinas/metabolismo , Carne , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Antibacterianos/metabolismo
8.
Int J Biol Macromol ; 256(Pt 1): 128286, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38000577

RESUMO

This study evaluated the effects of an edible bilayer containing polyphenols from the Euryale ferox seed shell on ready-to-eat cooked beef products, including the physical, mechanical, antioxidant, and antibacterial capabilities. Here, the bilayer films were prepared by layer-by-layer solution pouring using hydrophobic ethyl cellulose (EC) as the outer layer, and hydrophilic gelatin/carboxymethyl chitosan (GC) as the inner layer. By adjusting the proportion of gelatin to carboxymethyl chitosan, the optical, mechanical, and barrier characteristics of bilayer films were markedly enhanced. Extracted polyphenol (EP) from shell of the Euryale ferox seed performed potent antibacterial property against Listeria monocytogenes (L. monocytogenes). The addition of EP to the inner layer of the optimized bilayer film further improved the mechanical and barrier properties of films, and as expected, the film exhibited antioxidant and antibacterial abilities. Additionally, cooked beef and cooked chicken preservation tests indicated that the active bilayer film showed good inhibition of L. monocytogenes and delayed lipid oxidation in ready-to-eat meat products, and significantly delayed the pH, moisture loss, color and texture changes. This study developed multifunctional bilayer active edible films, which has a great potential in the preservation ready-to-eat cooked meat products.


Assuntos
Celulose/análogos & derivados , Quitosana , Conservação de Alimentos , Animais , Bovinos , Antioxidantes/farmacologia , Polifenóis , Quitosana/farmacologia , Gelatina , Carne/análise , Antibacterianos/farmacologia , Embalagem de Alimentos
9.
Oncogene ; 43(2): 136-150, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37973951

RESUMO

Impaired macroautophagy/autophagy flux has been implicated in the treatment of prostate cancer (PCa). However, the mechanism underlying autophagy dysregulation in PCa remains unknown. In the current study, we investigated the role of diacylglycerol acyltransferases 1 (DGAT1) and its potential effects on cellular energy homeostasis and autophagy flux in PCa. The results of immunohistochemical staining suggested that DGAT1 expression was positively corrected with tumor stage and node metastasis, indicating DGAT1 is an important factor involved in the development and progression of PCa. Furthermore, targeting DGAT1 remarkably inhibited cell proliferation in vitro and suppressed PCa growth in xenograft models by triggering severe oxidative stress and subsequently autophagy flux blockage. Mechanically, DGAT1 promoted PCa progression by maintaining cellular energy homeostasis, preserving mitochondrial function, protecting against reactive oxygen species, and subsequently promoting autophagy flux via regulating lipid droplet formation. Moreover, we found that fenofibrate exhibits as an upstream regulator of DGAT1. Fenofibrate performed its anti-PCa effect involved the aforementioned mechanisms, and partially dependent on the regulation of DGAT1. Collectively. These findings indicate that DGAT1 regulates PCa lipid droplets formation and is essential for PCa progression. Targeting DGAT1 might be a promising method to control the development and progression of PCa. Schematic representation of DGAT1 affects autophagy flux by regulating lipid homeostasis and maintaining mitochondrial function in prostate cancer (PCa). PCa is characterized up-regulation of DGAT1, leading to the translocation of free fatty acids into lipid droplets, thereby preventing PCa cell from lipotoxicity. Inhibition of DGAT1 suppresses growth of PCa by inducing oxidative stress and subsequently autophagy flux blockage. Further, the current results revealed that fenofibrate exhibits as an upstream regulator of DGAT1, and fenofibrate plays an anti-PCa role partially dependent on the regulation of DGAT1, suggesting a potential therapeutic approach to ameliorate this refractory tumor.


Assuntos
Fenofibrato , Neoplasias da Próstata , Humanos , Masculino , Autofagia , Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Diacilglicerol O-Aciltransferase/genética , Diacilglicerol O-Aciltransferase/metabolismo , Fenofibrato/metabolismo , Fenofibrato/farmacologia , Fenofibrato/uso terapêutico , Estresse Oxidativo , Próstata/patologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo
10.
J Liposome Res ; : 1-10, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37966062

RESUMO

Eugenol, as a natural antibacterial agent, has been widely studied for its inhibitory effect on the common food-borne pathogen Staphylococcus aureus (S. aureus). However, the widespread application of eugenol is still limited by its instability and volatility. Herein, γ-polyglutamic acid coated eugenol cationic liposomes (pGA-ECLPs) were successfully constructed by self-assembly with an average particle size of 170.7 nm and an encapsulation efficiency of 36.2%. The formation of pGA shell significantly improved the stability of liposomes, and the encapsulation efficiency of eugenol only decreased by 20.7% after 30 days of storage at 4 °C. On the other hand, the pGA layer can be hydrolyzed by S. aureus, achieving effective control of release through response to bacterial stimuli. The application experiments further confirmed that pGA-ECLPs effectively prolonged the antibacterial effect of eugenol in fresh chicken without causing obvious sensory effects on the food. The above results of this study provide an important reference for extending the action time of natural antibacterial substances and developing new stimuli-responsive antibacterial systems.

11.
Environ Sci Technol ; 57(45): 17393-17403, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37922235

RESUMO

Quantitative microbial risk assessment (QMRA) is presented as a tool for evaluation of the effectiveness of ultraviolet germicidal irradiation (UVGI) systems for the disinfection of indoor air. The QMRA is developed in the context of UVGI system implementation for control of SARS-CoV-2 infection and comprises submodels to address problem formulation, exposure assessment, and health effects assessment, all of which provide input to a risk characterization submodel. The model simulations indicate that UVGI systems can effectively control the risk of infection associated with SARS-CoV-2 for low to moderate virus emission rates. The risk of disease transmission is strongly influenced by the rate of pathogen emission by an infected individual, the output power of UVGI fixtures and their configuration, the source of UV-C radiation implemented in the UVGI fixtures, and the characteristics of the heating, ventilation, and air conditioning (HVAC) system. The QMRA framework provides a quantitative link between UVGI/HVAC system characteristics and changes in the risk of disease transmission. The framework can be adapted to other airborne pathogens and provides a rational basis for the design, testing, and validation of UVGI systems.


Assuntos
Microbiologia do Ar , COVID-19 , Humanos , SARS-CoV-2 , Raios Ultravioleta , Ventilação , Desinfecção
12.
Microb Pathog ; 184: 106375, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37774989

RESUMO

Food-borne pathogenic bacteria are a major public health concern globally. Traditional control methods using antibiotics have limitations, leading to the exploration of alternative strategies. Essential oils such as cardamom possess antimicrobial properties and have shown efficacy against food-borne pathogenic bacteria. The utilization of essential oils and their bioactive constituents in food preservation is a viable strategy to prolong the shelf-life of food products while ensuring their quality and safety. To the best of our knowledge, there are no studies that have utilized 1,8-cineole (the main active constituent of cardamom essential oil) as a preservative in meat, so this study might be the first to utilize 1,8-cineole as an antibacterial agent in meat preservation. The application of 1,8-cineole had a significant suppressive impact on the growth rate of Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella Typhimurium in meat samples stored for 7 days at 4 °C. Additionally, the surface color of the meat samples was not negatively impacted by the application of 1,8-cineole. The minimum inhibitory concentration was 12.5-25 mg/ml, and the minimum bactericidal concentration was 25-50.0 mg/ml. The bacterial cell membrane may be the target of cardamom, causing leakage of intracellular proteins, ATP, and DNA. The obtained data in this study may pave a new avenue for using 1,8-cineole as a new perspective for dealing with this problem of food-borne pathogens and food preservation, such as meat.


Assuntos
Elettaria , Listeria monocytogenes , Óleos Voláteis , Eucaliptol , Microbiologia de Alimentos , Carne/microbiologia , Óleos Voláteis/farmacologia , Antibacterianos/farmacologia , Bactérias , Escherichia coli , Testes de Sensibilidade Microbiana
13.
Environ Sci Pollut Res Int ; 30(49): 107716-107732, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37740805

RESUMO

Agricultural carbon emission reduction is an important issue in environmental protection and development in China and the world. The farmland spatial transition is an important path for agricultural modernization in developing countries such as China. How can farmland spatial transition promote agricultural carbon emission reduction? This paper aims to explore the mechanisms and spatial-temporal effects of farmland spatial transition on agricultural carbon emission density. To study the mechanisms and effects, we establish the random effect model, the threshold model, and the GTWR model with 2018 counties in China from 2000 to 2020. The research shows the farmland spatial transition mainly promotes agricultural carbon emission reduction through the interaction mechanism of large-scale production and specialized production, intermediary, and threshold mechanisms of agricultural technology. The result also shows that specialized farmland management is the main driving force of agricultural carbon emission reduction for farmland spatial transition. Moreover, the impact of farmland spatial transition on agricultural carbon emission reduction has significant spatial and temporal differences. The most significant regions are located in the middle and lower reaches of the Yangtze River plain, while the least are the north and southwest. Besides, the impact of the farmland spatial transition on agricultural carbon emissions reduction has a "V" shape over time, indicating China's agricultural carbon emission reduction is facing enormous economic and social development challenges. Our research reveals the various mechanisms and spatial-temporal effects of the transition of farmland spatial morphology on agricultural carbon emission with an evaluation framework, which is crucial to low-carbon agriculture with proper farmland use.


Assuntos
Agricultura , Tecnologia , Fazendas , China , Carbono , Dióxido de Carbono , Desenvolvimento Econômico
14.
Crit Rev Food Sci Nutr ; : 1-13, 2023 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37737159

RESUMO

The residue of Camellia seeds after oil extraction contains many bioactive ingredients, including tea saponin. Tea saponin has many pharmacological effects and is an excellent nonionic surfactant. The development of natural surfactants has become a hot topic in food research. This review gathers the applications of tea saponin as a surfactant in food. It focuses on the application of tea saponin in emulsions, delivery systems, extraction and fermentation, as well as the challenges and development prospects in food applications. Tea saponin shows great potential as a surfactant in food applications, which can replace some synthetic surfactants. The full utilization of tea saponin improves the comprehensive utilization value of Camellia seed residue, contributes to the sustainable development of Camellia industry and avoids resource waste.

15.
Int J Food Microbiol ; 400: 110266, 2023 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-37263173

RESUMO

Ultrasound technology has been focused on due to its unique advantages in biofilm removal compared with traditional antibacterial methods. Herein, the anti-biofilm properties of low-frequency ultrasound (LFUS) were studied against Enterohemorrhagic Escherichia coli O157: H7 (E. coli O157:H7). After ultrasonication (20 kHz, 300 W) for 5 min, the removal rate of biofilm from polystyrene sheets reached up to 99.999 %. However, the bacterial cells could not be inactivated completely even extending the duration of ultrasonic irradiation to 30 min. Fortunately, this study indicated that LFUS could efficiently weaken the metabolic capacity and biofilm-forming ability of bacterial cells separated from biofilm. It could be associated with the removal of cell surface appendages and damage to cell membrane induced by mechanical vibration and acoustic cavitation. Besides, the genetic analysis proved that the transcription level of genes involved in curli formation was significantly down-regulated during ultrasonic irradiation, thus impeding the process of irreversible adhesion and cells aggregation. Finally, the actual application effect of LFUS was also evaluated in different fresh produces model. The results of this study would provide a theoretical basis for the further application of ultrasound in the food preservation.


Assuntos
Biofilmes , Escherichia coli O157 , Microbiologia de Alimentos , Ondas Ultrassônicas , Escherichia coli O157/citologia , Escherichia coli O157/efeitos da radiação , Biofilmes/efeitos da radiação , Viabilidade Microbiana , Cucumis sativus/microbiologia , Cucumis sativus/efeitos da radiação , Cucumis melo/microbiologia , Cucumis melo/efeitos da radiação , /efeitos da radiação , Contaminação de Alimentos
16.
Int J Biol Macromol ; 242(Pt 1): 124686, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37146850

RESUMO

Environmental issues caused by plastic packaging materials have gotten increasingly severe, and substantial research has been conducted on environmentally friendly active packaging materials. In this study, the Litsea cubeba essential oil loaded soy protein isolate nanoparticles (LSNPs) with appropriate particle size, high storage stability and salt solution stability were fabricated. The LSNPs with the highest encapsulation efficiency of 81.76 % were added into the lentinan edible film. The microstructures of the films were observed by scanning electron microscopy. The physical properties of the films were measured. The results show that the lentinan film with LSNPs in the volume ratio of 4:1 (LF-4) had the highest elongation at break of 196 %, the lowest oxygen permeability of 12 meq/kg, and good tensile strength, water vapor barrier property, antibacterial property, oxidation resistance and thermal stability. The study suggested that LF-4 film could inhibit the growth of bacteria and delay the oxidation of lipid and protein on beef surface for 7 d.


Assuntos
Filmes Comestíveis , Litsea , Óleos Voláteis , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Proteínas de Soja/química , Lentinano , Embalagem de Alimentos/métodos , Resistência à Tração , Permeabilidade
17.
Front Plant Sci ; 14: 1145830, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37255563

RESUMO

Introduction: The production of root exudates with biological nitrification inhibition (BNI) effects is a strategy adopted by ammonium-N (NH4+-N) tolerant plant species that occur in N-limited environments. Most knowledge on BNI comes from plant species that occur in acidic soils. Methods: Here, combining field sampling and laboratory culture, we assessed the BNI-capacity of Leymus chinensis, a dominant grass species in alkaline grasslands in eastern Asia, and explored why L. chinensis has BNI ability. Results and discussion: The results showed that L. chinensis has strong BNI-capacity. At a concentration of 1 mg mL-1, L. chinensis' root exudates inhibited nitrification in soils influenced by Puccinellia tenuiflora by 72.44%, while DCD only inhibited it by 68.29%. The nitrification potential of the soil of L. chinensis community was only 53% of the P. tenuiflora or 41% of the Suaeda salsa community. We also showed that the supply of NH4+-N driven by L. chinensis' BNI can meet its requirements . In addition, NH4+-N can enhance plant adaptation to alkaline stress by regulating pH, and in turn, the uptake of nitrate-N (NO3--N). We further demonstrated that the regulatory function of NH4+-N is greater than its nutritional function in alkaline environment. The results offer novel insights into how L. chinensis adapts to high pH and nutrient deficiency stress by secreting BNIs, and reveal, for the first time, differences in the functional roles of NH4+-N and NO3--N in growth and adaptation under alkaline conditions in a grass species.

18.
Int J Biol Macromol ; 242(Pt 2): 124904, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37210052

RESUMO

Staphylococcus aureus (S. aureus) biofilms contamination on various food-contacting surfaces is considered a significant threat in the field of food. Poly-L-aspartic acid (PASP) was proven to damage biofilm by affecting bacterial adhesion, metabolic activity, and extracellular polymeric substances in this study. Especially for eDNA, its generation was reduced by 49.4 %. After treatment with 5 mg/mL of PASP, the number of S. aureus in the biofilm at different growth stages decreased by 1.20-1.68 log CFU/mL. The nanoparticles prepared by PASP and hydroxypropyl trimethyl ammonium chloride chitosan were used to embed LC-EO (EO@PASP/HACCNPs). The results indicated that the particle size of the optimized nanoparticles was 209.84 nm with an encapsulation rate of 70.28 %. Compared to LC-EO alone, EO@PASP/HACCNPs had more significant permeation and dispersion effects on biofilms and possessed long-lasting anti-biofilm activity. For the biofilm grown for 72 h, the population of S. aureus in the EO@PASP/HACCNPs-treated biofilm was additionally reduced by 0.63 log CFU/mL compared with the LC-EO-treated group. EO@PASP/HACCNPs were also applied to different food-contacting materials. The lowest inhibition rate of EO@PASP/HACCNPs on S. aureus biofilm still reached 97.35 %. The sensory properties of the chicken breast were not affected by EO@PASP/HACCNPs.


Assuntos
Litsea , Óleos Voláteis , Infecções Estafilocócicas , Staphylococcus aureus , Óleos Voláteis/farmacologia , Ácido Aspártico/farmacologia , Biofilmes
19.
Int J Biol Macromol ; 241: 124591, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37116847

RESUMO

Cassava starch/sodium carboxymethyl cellulose (CC) was used as the substrate to create a multipurpose food packaging film, and caffeic acid@silica nanoparticles (C@SNPs) was added. The encapsulation rate of caffeic acid in C@SNPs was 84.7 ± 0.97 %. According to SEM pictures, the nanoparticles were evenly dispersed throughout the film and exhibited good compatibility with the other polymers. C@SNPs was added, which enhanced the physical characteristics of film and decreased its water solubility. The best mechanical and oxygen barrier qualities among them are found in the C@SCC5:1 film, whose tensile strength rises from 7.17 MPa to 15.44 MPa. The C@SCC5:1 film has scavenging rates of 95.43 % and 84.67 % against ABTS and DPPH free radicals, respectively, and CA can be released continuously in various food systems. In addition, the antibacterial rate of E. coli O157:H7 and S. aureus of C@SCC5:1 film in meat was 99.9 %, and it can effectively delay lipid oxidation and pH rise. In conclusion,C@SCC5:1 film is a new type of antibacterial and antioxidant food packaging material.


Assuntos
Escherichia coli O157 , Manihot , Nanopartículas , Carboximetilcelulose Sódica , Staphylococcus aureus , Permeabilidade , Antibacterianos , Embalagem de Alimentos , Carne , Amido , Sódio
20.
Int J Biol Macromol ; 241: 124592, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37116846

RESUMO

This study evaluated the effects of adding various concentrations (0 %, 1 %, 2 %, and 3 %) of peach gum (PG) to films made from polyethylene oxide (PEO) combined with Litsea cubeba essential oil (LCEO) to be utilized as active packaging for food in the future. The findings showed that the film containing PG 2 % concentration had the best physic-mechanical properties. In films made with PG, the glass transition temperature was significantly improved. Combining PG and PEO resulted in films that were brighter in color, had lower WVP values, and had the lowest water activity. Furthermore, XRD demonstrated that PG additions were compatible with the film of PEO blended with LCEO. The PG films formulated with PG presented high antioxidant and antibacterial activity against Staphylococcus aureus and E. coli. Wrapping beef with P2G2 film led to maintaining its quality with suitable levels of pH, TBARS, and TVB-N. This also decreased the number of E. coli and S. aureus in beef throughout the storage period. The results indicate that adding PG to PEO films enhances their suitability for food preservation.


Assuntos
Litsea , Óleos Voláteis , Prunus persica , Animais , Bovinos , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Litsea/química , Escherichia coli , Staphylococcus aureus , Embalagem de Alimentos/métodos , Antibacterianos/farmacologia , Antibacterianos/química
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