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1.
Food Chem ; 460(Pt 1): 140442, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39047475

RESUMO

Soy isolate protein / chitooligosaccharide (SPI/COS) glycosylated conjugates was prepared and employed as an emulsifier to stabilize carvacrol-loaded nanoemulsions (CNE-SPI/COS). The effects of CNE-SPI/COS on the oxidation and aggregation of myofibrillar protein (MPs) from sea bass (Lateolabrax maculatus) were investigated. Samples were immersed in sterile water (CK), SPI/COS solution and CNE-SPI/COS solution, respectively, follow by a 15-day refrigerated storage. MPs were extracted from fish fillets at 3-day intervals, then assessed for the oxidation degree and conformational changes in MPs, as well as structural variations in myofibrils. Compared with the CK group, the results obtained from protein oxidation assessment clarified that the oxidation and aggregation of MPs was significantly reduced by the CNE-SPI/COS treatment, as evidenced by the higher total sulfhydryl content and Ca2+-ATPase activity and lower surface hydrophobicity. Conformational analysis of MPs showed that CNE-SPI/COS was effective in maintaining the ordered secondary structure of MPs and reducing the exposure of hydrophobic residues in the hydrophobic core of the tertiary structure. In addition, CNE-SPI/COS was found to be effective in protecting the microstructure of muscle fibers and myofibrils in fish fillets. These results suggest that CNE-SPI/COS can be a promising method to prevent protein oxidation and aggregation in fish.

2.
Int J Biol Macromol ; 273(Pt 2): 133225, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38897501

RESUMO

This work aimed to investigate the antibacterial ability and potential mechanism of chitosan grafted gentisate acid derivatives (CS-g-GA) against Pseudomonas fluorescens. The results showed that CS-g-GA had a significant suppressive impact on the growth of Pseudomonas fluorescens, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were 0.64 mg/mL and 1.28 mg/mL, respectively. Results of scanning electron microscopy (SEM) and alkaline phosphatase (AKPase) confirmed that CS-g-GA destroyed the cell structure thereby causing the leakage of intracellular components. In addition, 1 × MIC of CS-g-GA could significantly inhibit the formation of biofilms, and 74.78 % mature biofilm and 86.21 % extracellular polysaccharide of Pseudomonas fluorescens were eradicated by CS-g-GA at 2 × MIC. The results on the respiratory energy metabolism system and antioxidant system demonstrated that CS-g-GA caused respiratory disturbance and energy limitation by influencing the key enzyme activities. It could also bind to DNA and affect genetic metabolism. From this, it could be seen that CS-g-GA had the potential to control foodborne contamination of Pseudomonas fluorescens by attacking multiple targets.


Assuntos
Antibacterianos , Antioxidantes , Biofilmes , Quitosana , Gentisatos , Testes de Sensibilidade Microbiana , Pseudomonas fluorescens , Pseudomonas fluorescens/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Quitosana/farmacologia , Quitosana/química , Antibacterianos/farmacologia , Antibacterianos/química , Antioxidantes/farmacologia , Antioxidantes/química , Gentisatos/farmacologia , Gentisatos/química
3.
Int J Biol Macromol ; 273(Pt 1): 133029, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38852716

RESUMO

This study determined the inhibitory mechanism as well as anti-biofilm activity of chlorogenic acid-grafted-chitosan (CS-g-CA) against Pseudomonas fluorescens (P. fluorescens) in terms of biofilm content, oxidative stress, quorum sensing and cyclic diguanosine monophosphate (c-di-GMP) concentration, and detected the changes in the expression levels of related genes by quantitative real-time PCR (qRT-PCR). Results indicated that treatment with sub-concentrations of CS-g-CA for P. fluorescens led to reduce the biofilm size of large colonies, decrease the content of biofilm and extracellular polymers, weaken the motility and adhesion of P. fluorescens. Moreover, CS-g-CA resulted in higher ROS levels, diminished catalase activity (CAT), and increased superoxide dismutase (SOD) in P. fluorescens. CS-g-CA reduced the production of quorum-sensing signaling molecules (AHLs) and the concentration of c-di-GMP in bacteria. Genes for flagellar synthesis (flgA), the resistance to stress (rpoS and hfq), and pde (phosphodiesterases that degrade c-di-GMP) were significantly down-regulated as determined by RT-PCR. Overall, CS-g-CA leads to the accumulation of ROS in bacteria via P. fluorescens environmental resistance genes and decreases the activity of enzymes in the bacterial antioxidant system, and interferes with the production and reception of quorum-sensing signaling molecules and the synthesis of c-di-GMP in P. fluorescens, which regulates the generation of biofilms.


Assuntos
Biofilmes , Quitosana , Ácido Clorogênico , GMP Cíclico , Estresse Oxidativo , Pseudomonas fluorescens , Percepção de Quorum , Pseudomonas fluorescens/efeitos dos fármacos , Pseudomonas fluorescens/metabolismo , Quitosana/química , Quitosana/farmacologia , Biofilmes/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , GMP Cíclico/análogos & derivados , GMP Cíclico/metabolismo , Ácido Clorogênico/farmacologia , Ácido Clorogênico/química , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
4.
Int J Biol Macromol ; 274(Pt 1): 133276, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38906360

RESUMO

Chitosan is a natural polymer material with antibacterial, biodegradable and biocompatibility. At present, the research is mainly to enhance the antibacterial and antioxidant activity of chitosan by grafting with phenolic acids to further expand its application in food. In this study, the effect of chitosan-g-gentisic acid graft copolymer (CS-g-GA) on the shelf life of refrigerated seabass (Lateolabrax maculatus) was investigated. The results of microbial analysis demonstrated that GA and CS-g-GA treatment could effectively inhibit the growth of microorganisms. In addition, physicochemical analysis showed that GA and CS-g-GA treatment could reduce the increase of pH value, thiobarbituric acid reactive substances (TBARS), total volatile base nitrogen (TVB-N) and K-value, delay water loss, maintain texture and color, and postpone the decrease of sensory score. Compared with the control sample, CS-g-GA could keep the quality of Lateolabrax japonicus and extend its shelf-life for another 9 days. In summary, CS-g-GA has good application and development prospects for the preservation of seabass.

5.
Int J Biol Macromol ; 260(Pt 2): 129554, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38246458

RESUMO

In this study, a new natural preservative, ε-polylysine (ε-PL) and chitooligosaccharides (COS) Maillard reaction products (LC-MRPs), was prepared by Maillard reaction. The preservation effect of LC-MRPs combined with slightly acidic electrolyzed water (SAEW) pretreatment (SM) on vacuum-packed sea bass during refrigerated storage was evaluated. The results showed that after 16 days, SM treatment could effectively inhibit the microbial growth and prevent water migration in sea bass. In addition, the highest water holding capacity (69.79 %) and the best sensory characteristics, the lowest malonaldehyde (MDA) (58.96 nmol/g), trimethylamine (TMA) (3.35 mg/100 g), total volatile basic nitrogen (TVB-N) (16.93 mg N/100 g), myofibril fragmentation index (MFI) (92.2 %) and TCA-soluble peptides (2.16 µmol tyrosine/g meat) were related to SM group. Combined with sensory analysis, we can conclude that the combined treatment of SAEW and LC-MRPs could prolong the shelf-life of sea bass for another 11 days compared with the DW group. Results disclosed that the composite treatment of SAEW and LC-MRPs is a promising technology to improve the shelf-life of vacuum-packed sea bass during refrigerated storage.


Assuntos
Bass , Quitosana , Oligossacarídeos , Polilisina , Animais , Polilisina/farmacologia , Água , Vácuo , Reação de Maillard , Embalagem de Alimentos/métodos , Produtos Finais de Glicação Avançada , Conservação de Alimentos/métodos
6.
Food Chem ; 441: 138337, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38199114

RESUMO

This study synthesized five phenolic acid-chitosan copolymers utilizing the carbodiimide-mediated chemical crosslinking reaction. Comprehensive evaluations were conducted on their structural attributes, physicochemical properties, and biological activities. Fourier transform infrared confirmed successful grafting of phenolic acids onto chitosan via amide linkages. Additionally, ultraviolet-visible absorption spectroscopy and proton nuclear magnetic resonance analyses revealed novel absorption peaks between 200 and 400 nm and 6.0-8.0 ppm, respectively, attributable to the incorporated phenolic acids. Notably, the chitosan-gentisate acid copolymer exhibited significantly enhanced biological activity (p < 0.05) compared to pure chitosan and the other four conjugates, attributed to its highest grafting degree of approximately 295.93 mg/g. These modified chitosan derivatives effectively preserved the quality of sea bass (Lateolabrax japonicus) during refrigerated storage, extending its shelf-life by up to 9 days, 7 days, and 4 days relative to control, chitosan, and gentisate acid groups.


Assuntos
Bass , Quitosana , Animais , Quitosana/química , Gentisatos , Hidroxibenzoatos/química , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Food Chem ; 441: 138343, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38211477

RESUMO

The poor mechanical properties, low water-resistance, and limited antimicrobial activity of chitosan (CS)/polyvinyl alcohol (PVA) based film limited its application in aquatic product preservation. Herein, bacterial cellulose (BC) was used to load ginger essential oil (GEO). The effects of the addition of BC and different concentrations of GEO on the physicochemical and antimicrobial activities of films were systematically evaluated. Finally, the application of sea bass fillets was investigated. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD) analysis indicated dense networks were formed, which was verified by enhanced physical properties. The mechanical properties, barrier properties, and antimicrobial activities enhanced as GEO concentration increased. CPB0.8 (0.8 % GEO) film had better tensile strength (TS) and barrier performance, improved the quality, and extended the shelf-life of sea bass for another 6 days at least. Overall, active films are potential packaging materials for aquatic products.


Assuntos
Anti-Infecciosos , Bass , Quitosana , Óleos Voláteis , Zingiber officinale , Animais , Quitosana/química , Álcool de Polivinil/química , Celulose/química , Bactérias , Embalagem de Alimentos/métodos , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia
8.
Int J Biol Macromol ; 254(Pt 3): 127917, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37939754

RESUMO

Chitosan, a cost-effective and eco-friendly natural polymeric material, possesses excellent film-forming properties. However, it has low solubility and biological activity, which hinders its widespread applications. To overcome these limitations, researchers have developed phenolic acid-chitosan derivatives that greatly enhance the mechanical, antibacterial and antioxidant properties of chitosan, expanding its potential application, particularly in food preservation. This review aims to provide an in-depth understanding of the structure and biological activity of chitosan and phenolic acid, as well as various synthetic techniques employed in their modification. Phenolic acid-chitosan derivatives exhibit improved physicochemical properties, such as enhanced water solubility, thermal stability, rheological properties, and crystallinity, through grafting techniques. Moreover, these derivatives demonstrate significantly enhanced antibacterial and antioxidant activities. Through graft modification, phenolic acid-chitosan derivatives offer promising applications in food preservation for diverse food products, including fruits, vegetables, meat, and aquatic products. Their ability to improve the preservation and quality of these food items makes them an appealing option for the food industry. This review intends to provide a deeper understanding of phenolic acid-chitosan derivatives by delving into their synthetic technology, characterization, and application in the realm of food preservation.


Assuntos
Quitosana , Quitosana/farmacologia , Quitosana/química , Antioxidantes/farmacologia , Antioxidantes/química , Conservação de Alimentos/métodos , Antibacterianos/química , Embalagem de Alimentos
9.
Food Chem ; 440: 138198, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38128429

RESUMO

Natural antibacterials have stood out in the last decade due to the growing demand for reducing chemical preservatives in food. In particular, natural phenolic compounds are secondary metabolites produced by plants for numerous functions including antimicrobial defence. Polyphenol has significant antimicrobial activity, but its antimicrobial properties are affected by the cell structure difference of bacteria, the concentration, type, and extraction method of polyphenol, and the treatment time of bacteria exposed to polyphenol. Therefore, this paper analyzed the antibacterial activity and mechanism of polyphenol as an antimicrobial agent. However, there remained significant considerations, including the interaction of polyphenols and food matrix, environmental temperature, and the effect of color and odor of some polyphenols on sensory properties of aquatic products, and the additive amount of polyphenols. On this basis, the application strategies of polyphenols as the antimicrobial agent in aquatic products preservation were reviewed.


Assuntos
Anti-Infecciosos , Anti-Infecciosos/farmacologia , Fenóis/farmacologia , Polifenóis/farmacologia , Polifenóis/química , Antibacterianos/farmacologia , Antibacterianos/química , Antioxidantes/química
10.
Int J Food Microbiol ; 411: 110540, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38118358

RESUMO

This study investigated the effect of chlorogenic acid grafted chitosan (CS-g-CA) on the microbiota composition of sea bass (Lateolabrax japonicus), isolated and identified the specific spoilage organisms (SSOs) in the late stage of refrigerated fillets and evaluation of their spoilage potential. Moreover, antibacterial activity and membrane damage mechanism of CS-g-CA against spoilage bacteria was also investigated. Illumina-MiSeq high throughput sequencing results showed that CS-g-CA retarded the growth of Pseudomonas spp., which largely contributed to delaying the quality degradation of sea bass during storage. Then nine spoilage bacteria were isolated and identified from the fillets at the end of storage and inoculated into sterile fish fillets to determine their spoilage capacity. Results showed that fish fillets inoculated with spoilage bacteria exhibited a significant increase in TVB-N, TBA and putrescine content and decreased sensory quality during storage. Subsequently, the inhibitory activity of CS-g-CA against spoilage bacteria was investigated and strains that were more sensitive to the CS-g-CA with a strong spoilage capacity were selected for the study of the inhibition mechanism. Results suggested that CS-g-CA had strong inhibitory activity and led to bacterial death through the mechanism of membrane damage. Overall, this study analyzed the effect of CS-g-CA on the preservation of fish fillets from a microbiological point of view to provide a reference for the anti-bacterial preservation of aquatic products.


Assuntos
Bass , Quitosana , Animais , Bass/microbiologia , Conservação de Alimentos/métodos , Quitosana/farmacologia , Ácido Clorogênico/farmacologia , Bactérias , Armazenamento de Alimentos
11.
Foods ; 12(18)2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37761176

RESUMO

The effects of allicin and antioxidant of bamboo leaves (AOB) on the quality of bullfrogs (Lithobates catesbeiana) during refrigerated storage (4 °C) were investigated. The quality changes in samples treated with deionized water (CK), allicin solution (All), antioxidant of bamboo leaves (AOB), and allicin solution combined with AOB solution (AA) in microbiological, physicochemical, and sensory evaluation were analyzed, respectively. The results demonstrated that combination treatment inhibited the increase in total viable counts, delayed the decrease in amino acid content, and retarded the sensory deterioration. Preservative treatment has an inhibitory effect on the early storage of PBC, which can reduce PBC by about 1.0 log CFU/g. The reduction in thiobarbituric acid (TBA) content and total volatile basic nitrogen (TVB-N) content indicated that combination treatment could better restrain the lipid oxidation and degradation of protein than the CK group and single-treatment group. In addition, the TVB-N content in the AA group still did not exceed the threshold on the 14th day. As a consequence, combination treatment prolonged the shelf life of bullfrogs for another six days. Therefore, allicin and AOB with excellent antioxidant and antimicrobial activity could be an effective approach to delay the biochemical reaction of refrigerated bullfrogs. This study has provided a potential approach for increasing the shelf life of bullfrogs and preserving their quality during refrigerated storage.

12.
Food Chem ; 428: 136788, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37467692

RESUMO

Chitosan is a bio-renewable natural polymeric material. The antibacterial and antioxidant activity of chitosan can be enhanced by grafting with phenolic acids to further expand its application in food. Therefore, this paper focuses on reviewing the structure, antimicrobial and antioxidant activities and their mechanisms with phenolic acid-g-CS, evaluating its cytotoxicity, and describing its application in various food preservation. In general, different reaction mechanisms of phenolic acid-g-CS synthesis lead to different product structures. Compared to chitosan, phenolic acid-g-chitosan exhibited enhanced antibacterial and antioxidant activities. The toxicity assessment showed that phenolic acid-g-CS is not cytotoxic. Moreover, phenolic acid-g-CS has been applied to a variety of food products such as fruits, vegetables and meat with good results. Overall, this review provides a certain reference for subsequent researchers to design phenolic acid-g-CS more rationally and for the subsequent development of phenolic acid-g-CS in food preservation.


Assuntos
Antioxidantes , Quitosana , Antioxidantes/farmacologia , Antioxidantes/química , Quitosana/farmacologia , Quitosana/química , Antibacterianos/farmacologia , Antibacterianos/química , Conservação de Alimentos
13.
Food Chem ; 429: 136876, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37481985

RESUMO

Nanoemulsion-based technology is developing rapidly in the food industry, especially in the design of delivery systems for bioactive compounds. This review presents an in-depth understanding of the composition, function, antibacterial mechanism and successful application of nanoemulsions as preservative agents against fish spoilage. The results showed that the inclusion of bioactive substances in the food-grade nanoemulsions encapsulation system could improve its stability, control its release, inhibit the microbial growth and reproduction through a variety of targets. These nanoemulsions can inhibit fish spoilage via reducing microbial load and retarding the oxidation of proteins and lipids, thereby maintaining quality attributes of fish. In addition, nanoemulsions could be coupled with vacuum package for enhancing microbial destruction, retaining nutritional value and extending the shelf-life of fish. Accordingly, nanoemulsions are suggested as a promising strategy to inhibit fish spoilage.


Assuntos
Antibacterianos , Peixes , Animais , Oxirredução , Emulsões
14.
Food Funct ; 14(10): 4595-4606, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37158204

RESUMO

This study aimed to investigate the impact of chitosan-grafted-caffeic acid (CS-g-CA) and ultrasound (US) on myofibrillar proteins (MPs) in pompano (Trachinotus ovatus) during 24 days of ice storage. Fresh fish slices were treated with US (20 kHz, 600 W), CS-g-CA (G), and US combined with CS-g-CA (USG) for 10 min, respectively. Samples treated with sterile water served as study controls (CK). All samples were then stored in ice at 4 °C. The oxidation and degradation of MPs were evaluated at 4-day intervals. The results showed that US slightly accelerated the fragmentation of myofibrils, as confirmed by the increased myofibril fragmentation index (MFI). However, on day 24, the surface hydrophobicity (SH) of USG samples was 4.09 µg BPB bound/mg protein lower than that of G samples, and the total sulfhydryl content of USG samples was 0.50 µmol g-1 higher than that of G samples, suggesting that US could reinforce the antioxidant capacity of CS-g-CA. Regarding degradation of MPs, USG treatment maintained the secondary and tertiary structure of MPs by reducing the transition from ordered to disordered structures and by reducing the exposure of tryptophan residues. Sodium dodecyl sulphate- polyacrylamide gel electrophoresis (SDS-PAGE) showed that the inhibitory effect of USG on protein degradation may be related to the binding of CS-g-CA to MPs. The results of scanning electron microscopy (SEM) further clarified the fact that the USG treatment can protect the myofibril microstructure by maintaining the compact arrangement of muscle fibers. Additionally, USG treatment could improve the sensory properties of pompano. Overall, the synergistic effects of US and CS-g-CA can effectively delay the protein oxidation and degradation. The results provided in this study are valuable for the quality maintenance of marine fish.


Assuntos
Quitosana , Gelo , Animais , Oxirredução , Antioxidantes , Peixes
15.
World J Microbiol Biotechnol ; 39(7): 188, 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37156898

RESUMO

Vibrio parahaemolyticus has become an important public threat to human health. Rapid and robust pathogen diagnostics are necessary for monitoring its outbreak and spreading. Herein, we report an assay for the detection of V. parahaemolyticus based on recombinase aided amplification (RAA) combined with lateral flow dipstick (LFD), namely RAA-LFD. The RAA-LFD took 20 min at 36~38 â„ƒ, and showed excellent specificity. It detected as low as 6.4 fg/µL of V. parahaemolyticus in genomic DNA, or 7.4 CFU/g spiked food samples with 4 h of enrichment. The limit of detection in shrimp (Litopenaeus Vannamei), fish (Carassius auratus), clam (Ruditapes philippinarum) evidenced that sensitivity was considerably affected by the food matrix. The presence of food matrix reduced the sensitivity of spiked food samples by 10 ~ 100 times. In the filed samples detection, RAA-LFD method showed good coincidence with GB4789.7-2013 method and PCR method at rates of 90.6% and 94.1%, respectively. RAA-LFD has high accuracy and sensitivity for the detection of V. parahaemolyticus, which can serve as a model tool to meet the growing need for point-of-care diagnosis of V. parahaemolyticus.


Assuntos
Vibrio parahaemolyticus , Animais , Humanos , Vibrio parahaemolyticus/genética , Sensibilidade e Especificidade , Reação em Cadeia da Polimerase/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Alimentos Marinhos , Hidrolases
16.
Lett Appl Microbiol ; 76(4)2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-37081770

RESUMO

This study aimed to examine the inhibition of chlorogenic acid-grafted chitosan (CS-g-CA) on Pseudomonas fluorescens (P. fluorescens) and its biofilm. The minimum inhibitory concentration (MIC) of CS-g-CA against P. fluorescens was 1.25 mg/mL. Alkaline phosphatase (AKPase) leakage assay and scanning electron microscopy (SEM) observation showed that CS-g-CA causes structural damage to cell walls and membranes, resulting in the loss of function. In addition, CS-g-CA was able to disrupt the antioxidant system of P. fluorescens, interfere with energy metabolism, and interact with genomic DNA, affecting the normal physiological function of bacteria. It was also found that CS-g-CA inhibited the flagellar motility of P. fluorescens, which may be responsible for the inhibition of its biofilm formation. CS-g-CA at 2MIC was able to remove 71.64% of the mature biofilm and reduce the production of extracellular polysaccharides (EPS) by 60.72%. This was further confirmed by confocal laser scanning microscopy (CLSM), which showed a significant reduction in the amount of biofilm. In summary, CS-g-CA has strong antibacterial and anti-biofilm activities against P. fluorescens, and it can be applied as a potential seafood bacteriostatic agent.


Assuntos
Quitosana , Pseudomonas fluorescens , Quitosana/farmacologia , Quitosana/química , Pseudomonas fluorescens/fisiologia , Ácido Clorogênico/farmacologia , Biofilmes , Antibacterianos/farmacologia , Antibacterianos/química , Alimentos Marinhos/microbiologia
17.
Antibiotics (Basel) ; 12(2)2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36830275

RESUMO

Salmonella enterica is a major cause of foodborne illness, and the emergence of antibiotic-resistant bacteria has led to huge pressures on public health. Phage is a promising strategy for controlling foodborne pathogens. In this study, a novel Salmonella phage vB_SalM_SPJ41 was isolated from poultry farms in Shanghai, China. Phage vB_SalM_SPJ41 was able to lyse multiple serotypes of antibiotic-resistant S. enterica, including S. Enteritidis, S. Typhimurium, S. Shubra, S. Derby, and S. Nchanga. It had a short incubation period and was still active at a temperature <80 °C and in the pH range of 3~11. The phage can effectively inhibit the growth of S. enterica in liquid culture and has a significant inhibitory and destructive effect on the biofilm produced by antibiotic-resistant S. enterica. Moreover, the phage was able to reduce S. Enteritidis and MDR S. Derby in lettuce to below the detection limit at 4 °C. Furthermore, the phage could reduce S. Enteritidis and S. Derby in salmon below the limit of detection at 4 °C, and by 3.9 log10 CFU/g and· 2.1 log10 CFU/g at 15 °C, respectively. In addition, the genomic analysis revealed that the phages did not carry any virulence factor genes or antibiotic resistance genes. Therefore, it was found that vB_SalM_SPJ41 is a promising candidate phage for biocontrol against antibiotic-resistant Salmonella in ready-to-eat foods.

18.
Biochem Biophys Res Commun ; 650: 30-38, 2023 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-36773337

RESUMO

Chitooligosaccharides can be combined with amino acids or polypeptide to form Maillard reaction products (MRPs) with the antibacterial characteristics through Maillard reaction. This research aims to clarify the structure, antimicrobial effect and mechanism against Shewanella putrefaciens (S. putrefaciens) of ε-polylysine and chitooligosaccharides Maillard reaction products (LC-MRPs). The results of intrinsic fluorescence (IF) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction, proton nuclear magnetic resonance (1H NMR) spectra and scanning electron microscope (SEM) indicated Maillard reaction occurred between ε-polylysine and chitooligosaccharides. The observation of confocal laser scanning microscopy (CLSM), SEM and growth curves of S. putrefaciens evidenced that LC-MRPs have the strongest antibacterial effects. The leakage of alkaline phosphatase (AKP) and lactate dehydrogenase (LDH) implied that LC-MRPs sabotaged bacterial barrier (cell wall and cell membrane). The changes in content of nucleic acids, reactive oxygen species (ROS) level, lipid peroxidation content (LPO), succinate dehydrogenase (SDH) activity and adenosine triphosphate (ATP) content showed LC-MRPs will affect bacterial genetic gene transcription, material and energy metabolism. Therefore, the LC-MRPs were effective antibacterial agents to inhibit S. putrefaciens, which will help to preserve food with S. putrefaciens as the main spoilage bacteria.


Assuntos
Anti-Infecciosos , Polilisina , Polilisina/química , Espectroscopia de Infravermelho com Transformada de Fourier , Antibacterianos/farmacologia , Reação de Maillard , Produtos Finais de Glicação Avançada/química
19.
J Sci Food Agric ; 103(1): 152-163, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-35848059

RESUMO

BACKGROUND: The Maillard reaction is a promising and safe method for obtaining chitooligosaccharide conjugates with proteins or peptides as food preservatives. This study aims to investigate the moisture state, physicochemical properties, and shelf-life of sea bass fillets treated with ε-polylysine (ε-PL) and chitooligosaccharides (COS), which are Maillard reaction products (LC-MRPs), during refrigerated storage. RESULTS: The results of microbiological analysis and confocal laser scanning microscope (CLSM) revealed that LC-MRPs could retard microbial growth effectively. Compared with control, other treated groups could strongly retard the increase in the thiobarbituric acid (TBA) value, the K-value and the total volatile basic nitrogen (TVB-N) value, and also inhibited the softening of texture and the accumulation of biogenic amines in fish. The results of low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) indicate that LC-MRPs could delay the water migration of fillets and increase water holding capacity (WHC). Through sensory evaluation, the application of LC-MRPs increased the shelf-life of refrigerated sea bass fillets for another 9 days. CONCLUSION: Maillard reaction products derived from chitooligosaccharides and ε-polylysine have strong potential for preserving sea bass. © 2022 Society of Chemical Industry.


Assuntos
Bass , Animais , Bass/microbiologia , Polilisina , Produtos Finais de Glicação Avançada , Água , Armazenamento de Alimentos , Conservação de Alimentos/métodos
20.
J Sci Food Agric ; 103(8): 3787-3798, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36224103

RESUMO

BACKGROUND: Different ice treatments were applied for the preservation of mackerel (Pneumatophorus japonicus). The quality changes of samples treated with flake ice (Control), slurry ice (SI) and slightly acidic electrolyzed water-slurry ice (SAEW-SI) in microbiological, physicochemical, protein characteristic, and sensory evaluation were investigated during chilled storage. RESULTS: SAEW-SI showed a significant advantage for the inhibition of microbial growth, which could extend the shelf-life for another 144 h at least, compared with Control group. SAEW-SI treatment also showed a strong inhibition for the increase in pH, total volatile basic nitrogen (TVB-N), K-value, histamine and metmyoglobin (MetMb) content. Results of texture profile analysis (TPA) and water holding capacity (WHC) indicated that SAEW-SI can obviously suppress the decrease of hardness value, and have a better protective effect on muscle structure compared to flake ice and SI (P < 0.05). During the whole experiment, the highest sensory scores and a* were obtained in the SAEW-SI group, which indicated that SAEW-SI treatment could maintain better sensory characteristics. According to the results of thiobarbituric acid reactive substances (TBARS) and fluorescence spectroscopy analysis, SAEW-SI treatment could effectively retard protein degradation and lipid oxidation compared with Control and SI group. In maintaining the quality of mackerel, SAEW-SI shows a better effect than SI due to the synergistic effect of fence factors. CONCLUSION: The results demonstrated that the shelf-life of mackerel could be extended and the quality of mackerel could be maintained effectively with SAEW-SI treatment during chilled storage. © 2022 Society of Chemical Industry.


Assuntos
Gelo , Perciformes , Animais , Conservação de Alimentos/métodos , Água/química , Expectativa de Vida
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