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Edible films are effective alternatives to plastic packaging, however, the hydrophilicity of edible films based on protein and polysaccharide limits the application. Therefore, we fabricated a water-stable hybrid film with a linear-spherical interpenetrating molecular topology network using egg white (EW), chitosan (CS), and pectin. Meanwhile, the nisin-tannin acid self-assembly complex nanoparticles were employed as a multifunctional cross-linker, antibacterial and antioxidant agent to improve the performance of films. The FTIR, XRD, and SEM analysis revealed that the conformation and crystalline structure rearrangement of chitosan induced by the alkaline environment provided by egg white enhanced the network structure of films, effectively avoided the addition of modifying reagents. The proposed hybrid films exhibited excellent properties, with EW/TNPCS3 showing the best overall performance. The water contact angle (WCA) increased to 105.27 ± 1.62°, and its dissolution and swelling rates were significantly lower than pure egg white and pure chitosan films. Moreover, tannin-nisin (TN) nanoparticles endowed the films with excellent antimicrobial activity against the common Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Thus, the prepared blending films have great application potential in food preservation, especially to maintain stable performance in high humidity environment.
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Egg yolk production processed after separating egg white is a common method to shorten cycle, but its taste quality will change even the vitelline membrane is intact. This might be related to the slight non-destructive deformation causing redistribution and fusion of protein-lipid assemblies within the egg yolk spheres. We investigated the mechanism of the change in thermal gel properties under slight deformation. The results of microscopic structural morphology revealed that the whole boiled egg yolk (WEY) underwent a transition in protein-lipid assembly morphology within yolk spheres, which changed from local aggregation to disordered fusion in shaken boiled egg yolks (SEYs). The spectroscopic and physicochemical properties analysis demonstrated that the redistribution of protein-lipid assemblies gave rise to marked changes in water migration, texture properties, molecular interactions, and oral sensation simulation of egg yolk thermal gels. This is benefit to guide the regulation of the taste quality egg yolk products in industry.
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A fundamental regulatory framework to elucidate the role of electrical stimulation (ES) in reducing long production cycles, enhancing protein utilization, and boosting product quality of dry-cured ham is essential. However, how mitochondria and enzymes in meat fibers are altered by ES during post-processing, curing, and fermentation procedures remains elusive. This study sought to explore the impact of ES on the regulation of heat shock proteins (HSP27, HSP70), apoptotic pathways, and subsequent influences on dry-cured pork loin quality. The gathered data validated the hypothesis that ES notably escalates mitochondrial oxidative stress and accelerates mitochondrial degradation along the ripening process. The proapoptotic response in ES-treated samples was increased by 120.7%, with a cellular apoptosis rate 5-fold higher than that in control samples. This mitochondrial degradation is marked by increased ratios of Bax/Bcl-2 protein along the time course, indicating that apoptosis could contribute to the dry-cured ham processing. ES was shown to further down-regulate HSP27 and HSP70, establishing a direct correlation with the activation of mitochondrial apoptosis pathways, accompanied by dry-cured ham quality improvements. The findings show that ES plays a crucial role in facilitating the ripening of dry-cured ham by inducing mitochondrial apoptosis to reduce HSP expression. This knowledge not only explains the fundamental mechanisms behind myofibril degradation in dry-cured ham production but also offers a promising approach to enhance quality and consistency.
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Dry-cured meat products are gaining attention owing to their distinctive sensory characteristics and health benefits. In this study, two Debaryomyces hansenii strains were investigated for their potential as starter cultures for dry-cured pork belly products. After preliminary screening, these D. hansenii strains, namely, S20 and S26, both exhibiting with excellent aroma-producing capacity in a dry-cured meat model, were selected as single-strain starter cultures. For comparison, a non-inoculated control was also evaluated. In S20- and S26-inoculated pork belly, yeast dominated the microbiota and improved microbiological safety by suppressing Enterobacteriaceae growth. Compared with the non-inoculated control, the inoculated pork belly yielded higher hardness and redness (a*) values. Starter culture inoculation accelerated proteolysis in pork belly, improving the content of total free amino acids (TFFAs) and several essential free amino acids (Thr, Val, Met, Ile, Leu, and Phe) at the end of processing. Moreover, the inoculated samples exhibited higher levels of fat oxidation-derived aldehydes as well as esters, acids, alcohols and other compounds than the non-inoculated control at the end of the 95-day ripening period. Overall, these findings provide new insights into the application of D. hansenii isolated from dry-cured ham to dry-cured pork belly.
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Debaryomyces , Microbiologia de Alimentos , Produtos da Carne , Animais , Produtos da Carne/microbiologia , Produtos da Carne/análise , Suínos , Humanos , Paladar , Valor Nutritivo , Aminoácidos/análise , Manipulação de Alimentos/métodos , Fermentação , Carne de Porco/microbiologia , Carne de Porco/análise , Odorantes/análise , Proteólise , MasculinoRESUMO
BACKGROUND: The genomic information available for Pediococcus pentosaceus is primarily derived from fermented fruits and vegetables, with less information available from fermented meat. P. pentosaceus LL-07, a strain isolated from fermented meat, has the capability of producing exopolysaccharides (EPS). To assess the probiotic attributes of P. pentosaceus LL-07, we conducted whole-genome sequencing (WGS) using the PacBio SequelIIe and Illumina MiSeq platforms, followed by in vitro experiments to explore its probiotic potential. RESULTS: The genome size of P. pentosaceus LL-07 is 1,782,685 bp, comprising a circular chromosome and a circular plasmid. Our investigation revealed the absence of a CRISPR/Cas system. Sugar fermentation experiments demonstrated the characteristics of carbohydrate metabolism. P. pentosaceus LL-07 contains an EPS synthesis gene cluster consisting of 13 genes, which is different from the currently known gene cluster structure. NO genes associated with hemolysis or toxin synthesis were detected. Additionally, eighty-six genes related to antibiotic resistance were identified but not present in the prophage, transposon or plasmid. In vitro experiments demonstrated that P. pentosaceus LL-07 was comparable to the reference strain P. pentosaceus ATCC25745 in terms of tolerance to artificial digestive juice and bile, autoaggregation and antioxidation, and provided corresponding genomic evidence. CONCLUSION: This study confirmed the safety and probiotic properties of P. pentosaceus LL-07 via complete genome and phenotype analysis, supporting its characterization as a potential probiotic candidate.
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Fermentação , Genoma Bacteriano , Pediococcus pentosaceus , Polissacarídeos Bacterianos , Probióticos , Pediococcus pentosaceus/genética , Pediococcus pentosaceus/metabolismo , Polissacarídeos Bacterianos/metabolismo , Polissacarídeos Bacterianos/biossíntese , Sequenciamento Completo do Genoma , Alimentos Fermentados/microbiologia , Carne/microbiologia , Família Multigênica , Genômica/métodos , Humanos , Plasmídeos/genética , Microbiologia de AlimentosRESUMO
The effects of perilla seed oil high internal phase emulsions stabilized by pea protein (PP-PSO HIPEs) on the gel properties and conformation of myofibrillar protein (MP) gels were investigated. The results showed that the PP-PSO HIPEs with 4.0 % (w/v) PP formed stable HIPEs with low droplet size and good viscoelasticity. The addition of PP-PSO HIPEs (5.0 % - 15.0 %) could significantly improve the MP gel properties (P < 0.05), while the addition of 10.0 % PP-PSO HIPEs showed the highest gel strength and water holding capacity. Otherwise, the MP gels with 10.0 % PP-PSO HIPEs showed higher proportions of immobile water (PT22) and lower proportion of free water (PT23), and the Raman spectra suggested that the content of α-helix decreased, while the content of ß-sheet increased (P < 0.05), thus facilitating the formation of better gel properties. Therefore, the addition of PP-PSO HIPEs is a potential alternative for developing fat-reduced meat products.
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One of the most consistent epidemiological associations between diet and human disease risk is the impact of consuming red meat and processed meat products. In recent years, the health concerns surrounding red meat and processed meat have gained worldwide attention. The fact that humans have lost the ability to synthesize N-glycolylneuraminic acid (Neu5Gc) makes red meat and processed meat products the most important source of exogenous Neu5Gc for humans. As our research of Neu5Gc has increased, it has been discovered that Neu5Gc in red meat and processed meat is a key factor in many major diseases. Given the objective evidence of the harmful risk caused by Neu5Gc in red meat and processed meat to human health, there is a need for heightened attention in the field of food. This updated review has several Neu5Gc aspects given including biosynthetic pathway of Neu5Gc and its accumulation in the human body, the distribution of Neu5Gc in food, the methods for detecting Neu5Gc, and most importantly, a systematic review of the existing methods for reducing the content of Neu5Gc in red meat and processed meat. It also provides some insights into the current status and future directions in this area.
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Produtos da Carne , Ácidos Neuramínicos , Carne Vermelha , Ácidos Neuramínicos/química , Produtos da Carne/análise , Produtos da Carne/efeitos adversos , Humanos , Animais , Carne Vermelha/análise , Carne Vermelha/efeitos adversosRESUMO
BACKGROUND: Experiences of being bullied in school can impair adolescents' subjective well-being and elevate the risk of psychopathology, suggesting the necessity of identifying factors that may protect against the deleterious effects of being bullied. This study expands upon prior research by examining the relationship between bullying victimization and adolescent mental health, specifically from the perspective of individual perceptions of justice and healthy lifestyles in the Chinese cultural context. METHODS: A total of 3873 Chinese adolescents in grades 7-11 (51.85 % female) completed bullying victimization, belief in a just world, health promoting lifestyle, depressive symptoms, and subjective well-being measures, and provided information on their demographics, including gender, grade, family structure, parents' educational background. RESULTS: After adjusting for demographic variables, bullying victimization was directly and positively related to depression, while directly and negatively related to subjective well-being. Bullying victimization also influenced depression and subjective well-being through three mediation pathways, with belief in a just world and health promoting lifestyle playing multiple mediating roles in the relationship between bullying victimization and mental health outcomes. LIMITATIONS: The data used in this study were self-reported by adolescents and measured via cross-sectional designs, thus precluding statistical examination of temporal causal relationships, and assessments of whether reported affects are stable over time. CONCLUSIONS: The study suggests that belief in a just world and health promoting lifestyle are important factors in understanding the impact of bullying victimization on adolescent mental health, and underscores the need for targeted bullying interventions for at-risk adolescents.
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Bullying , Vítimas de Crime , Humanos , Adolescente , Feminino , Masculino , Saúde Mental , Estudos Transversais , Bullying/psicologia , Vítimas de Crime/psicologia , China , Promoção da Saúde , Estilo de VidaRESUMO
Background: China is comprehensively promoting the construction of social psychological service system. Social organizations provide psychosocial care services to migrant children in China and hold important information and perspectives different from educators and parents on children's mental health. This study aims to analyze mental health service delivery to migrant adolescents for their psychological well-being, to explore how society responds effectively to their psychological needs and to support in better program implementation of mental health services for migrant children. Methods: Following qualitative approach semi-structured interviews were conducted with community mental health service providers experienced in working with migrant children. The 15 individual interviews were conducted in Hubei province and Guangdong province, including professionals working with different social organization and social psychological service program in communities. The data were analysed through coding, comparing fragments, constant comparison and recognizing patterns. Results: The analysis yielded 3 categories (Stimulate the internal strength, Reconstruct the support systems, Understanding and participate in social activities) and 6 sub-categories (Improve the understanding of "me" and explore excellent qualities, Clearly envision "my" future and clear career planning, Improve the parent-child relationship and understand the family environment, Improve subjective support and actively develop support system, Acquire reasonable cognition and behavior and interact with surrounding ecology, Take greater responsibility and cultivate a sense of ownership). The results found that individual traits, family, communities and multiple factors affect the mental health of migrant children and identified the urgent needs, and ways to improve mental health service in efficiently and economically. Social psychological service providers contribute in strengthening the psychological well-being of the migrant children. Conclusion: Social psychological service sectors need to be strengthened to enhance the psychological well-being of the migrant children. The inherent gaps between the service required and service provided needs to be addressed through further studies on mental health needs of the migrant children.
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This study aimed to investigate the structural and functional changes in polyhydroxy alcohol-mediated curing on pork myofibrillar proteins (MP). The results obtained from total sulfhydryl groups, surface hydrophobicity, fluorescence and Raman spectroscopies, and solubility demonstrated that the polyhydroxy alcohols (especially xylitol) significantly modified the MP tertiary structure, making this structure more hydrophobic and tighter. However, no significant differences were detected in the secondary structure. Furthermore, the thermodynamic analysis revealed that polyhydroxy alcohols could develop an amphiphilic interfacial layer on the MP surface, significantly increasing the denaturation temperature and enthalpy of denaturation (P < 0.05). On the other hand, the molecular docking and dynamics simulations showed that polyhydroxy alcohols interact with actin mainly through hydrogen bonds and van der Waals forces. Therefore, this could help reduce the effect of high-content salt ions on MP denaturation and improve the cured meat quality.
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Carne de Porco , Carne Vermelha , Suínos , Animais , Simulação de Acoplamento Molecular , Etanol , Simulação por ComputadorRESUMO
This study explored the effect of yolk sphere on gel state and taste differences between whole boiled egg yolk (WBEY) and stirred boiled egg yolks (SBEYs). Optical microscopy, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM) indicated that the WBEY was formed via the accumulation of yolk spheres, whereas the SBEY was a gel with a tight and ordered microstructure. The stirring disrupted the yolk sphere structure, leading to a homogeneous distribution of proteins and lipids in SBEYs, and a cross-linked network in gel was established with higher hardness and springiness. In the oral sensation simulation, WBEY had a higher saliva adsorption capacity and frictional force to oral soft tissue during swallowing than SBEY. This work contributes to a deeper understanding of the gel structure and taste of egg yolk, and provides a theoretical basis for the research on the formation of the gritty taste of egg yolks.
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Gema de Ovo , Ovos , Animais , Citoplasma , Gema de Ovo/química , Microscopia Eletrônica de Varredura , SensaçãoRESUMO
NaCl is the main curing agent in dry-cured meat products, and a large amount of NaCl addition leads to high salt content of final products. Salt content and composition are important factors affecting the activity of endogenous proteases, which in turn could affect proteolysis as well as the quality of dry-cured meat products. With the increasing emphasis on the relationship between diet and health, reducing sodium content without sacrificing quality and safety of products is a great challenge for dry-cured meat industry. In this review, the change of endogenous proteases activity during processing, the potential relationship between sodium reduction strategy, endogenous proteases activity, and quality were summarized and discussed. The results showed that sodium replacement strategy and mediated-curing had a complementary advantage in influencing endogenous proteases activity. In addition, mediated-curing had the potential to salvage the negative effects of sodium substitution by affecting endogenous proteases. Based on the results, a sodium reduction strategy that sodium replacement in conjunction with mediated-curing based on endogenous proteases was proposed for the future perspective.
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Polyhydroxy alcohol-mediated curing has great potential for producing low-salt cured meat products. This study investigated the mass transfer kinetics and the one-way diffusion simulation of sodium chloride (NaCl) during the curing process. Furthermore, Fick's second law determined the NaCl diffusion coefficient (De) of xylitol-mediated cured pork tenderloin. The results demonstrated that adding xylitol could reduce the De of NaCl. The De of NaCl, calculated using the one-way model, was 1.29 × 10-9 m2·s-1, 1.22 × 10-9 m2·s-1, 1.2 × 10-9 m2·s-1, and 1.15 × 10-9 m2·s-1 when the amount of xylitol added was 0%, 4%, 8%, and 12% (w/w), respectively. This result agrees with the predicted values from the power function time-varying model. Moreover, a three-dimensional simulating model of mass transfers constructed using COMSOL Multiphysics was developed to evaluate the NaCl diffusion in pork tenderloin during the curing process. This model has high accuracy and can be used to describe the diffusion of NaCl in curing. Overall, this study provided a foundation for NaCl diffusion and distribution during the curing process.
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Piophila casei is a flesh-feeding Diptera insect that adversely affects foodstuffs, such as dry-cured ham and cheese, and decaying human and animal carcasses. However, the unknown mitochondrial genome of P. casei can provide information on its genetic structure and phylogenetic position, which is of great significance to the research on its prevention and control. Therefore, we sequenced, annotated, and analyzed the previously unknown complete mitochondrial genome of P. casei. The complete mt genome of P. casei is a typical circular DNA, 15,785 bp in length, with a high A + T content of 76.6%. It contains 13 protein-coding genes (PCG), 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and 1 control region. Phylogenetic analysis of 25 Diptera species was conducted using Bayesian and maximum likelihood methods, and their divergence times were inferred. The comparison of the mt genomes from two morphologically similar insects P. casei and Piophila megastigmata indicates a divergence time of 7.28 MYA between these species. The study provides a reference for understanding the forensic medicine, taxonomy, and genetics of P. casei.
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Dípteros , Genoma Mitocondrial , Animais , Humanos , Dípteros/genética , Filogenia , Genoma Mitocondrial/genética , Teorema de Bayes , Insetos/genéticaRESUMO
Mould and mycotoxin contamination is an ongoing issue in agriculture and food industry. Production by Aspergillus niger DTZ-12 in Guizhou dried red chilies was found, leading to significant economic losses. In this study, the inhibitive efficacy (Effective Concentration, EC) of cinnamaldehyde (CIN), eugenol (EUG), carvacrol (CAR), and linalool (LIN) against A. niger DTZ-12 were evaluated. CIN with the best antifungal capacity was then investigated for the comprehensive inhibitory activity against A. niger DTZ-12 including mycelia, spores, and physiological activities. Results showed that CIN can effectively retard mycelial growth, spore germination, and OTA production of A. niger DTZ-12 in vitro and in dried red chilies during storage. At physiological level, CIN can increase cell membrane permeability by reducing the ergosterol, decrease ATP content and ATPase activity, and promote the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) in cell. These results suggested that CIN displayed a great potential to be employed as a natural and effective alternative preservative during dried red chili storage.
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Acroleína , Aspergillus niger , Acroleína/farmacologia , Acroleína/metabolismo , Antifúngicos/farmacologia , Antifúngicos/metabolismoRESUMO
The unique processing technology of dry-cured meat products leads to strong proteolysis, which produces numerous peptides. The purpose of this investigation was the systematic isolation, purification, and identification of potentially cardioprotective bioactive peptides from dry-cured pork coppa during processing. According to the results of anti-platelet-activating factor acetyl hydrolase activity and radical scavenging ability in vitro, the inhibitory effect of M1F2 in purified fractions on cardiovascular inflammation was higher than that of M2F2. The peptide of M1F2 was identified by nano-liquid chromatography-tandem mass spectrometry. A total of 30 peptides were identified. Based on bioinformatics methods, including in silico analysis and molecular docking, LTDKPFL, VEAPPAKVP, KVPVPAPK, IPVPKK, and PIKRSP were identified as the most promising potential platelet-activating factor acetyl hydrolase inhibitory peptides. Overall, bioactive peptides produced during dry-cured pork coppa processing demonstrate positive effects on human health.
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This study focused on how different concentrations of tea branch liquid smoke (TLS) in the curing solution impacted the physicochemical properties and antioxidant properties of pork tenderloin. Five experimental (1.25 mL/kg, 2.5 mL/kg, 5 mL/kg, 10 mL/kg, 20 mL/kg) and blank groups set up over 4 days, and it was found that the physicochemical indexes, antioxidant capacity, thermal stability and protein network structure of the cured meat using 5 mL/kg of liquid smoke were excellent than the other groups used (P < 0.05). However, concentrations at 20 mL/kg accelerated protein oxidation. Low frequency nuclear magnetic resonance (LFNHR) revealed that TLS also improved the water holding capacity of the cured meat by increasing the percentage of bound water. Additionally, the correlation analysis demonstrated that the inoxidizability of myofibrillar protein was significantly related to cooking loss and water distribution, which were adjusted by changing the usage of liquid smoke.
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In this study, the impacts of loin ham with sorbitol-mediated curing on its physicochemical properties and bacterial community composition during fermentation and ripening were investigated. The salt content, pH, and water activity (aw) were lower in the sorbitol group than in the control group throughout the fermentation and ripening stages (P < 0.05). In addition, the L* values were higher in the sorbitol group (P < 0.05). Additionally, microbial diversity diminished in all groups as the fermentation and ripening process proceeded, with Lactobacillus turning into the dominant genus in the control group and Staphylococcus and Lactobacillus becoming dominant in the sorbitol group. Pearson's correlation analysis confirmed that the physicochemical properties have been significantly correlated with the bacterial community. In conclusion, sorbitol-mediated curing not only facilitates salt reduction while prolonging the storage period of loin ham, but also improves the distribution of bacterial community in loin ham and enhances its quality.
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Chinese traditional fermented meat products in Guizhou province harbor a unique microbial community owing to particular geographical, environmental, and climatic conditions. In this study, coagulase-negative staphylococci (CNS) with high protease activity were isolated from a Guizhou traditional naturally fermented meat product, i.e., Qianwufu sausages. In addition, the potential of isolated CNS strains to be used as starter cultures in sausage fermentation was evaluated. Culture- and molecular-biology-based methods were employed to isolate and identify CNS. A total of 40 CNS strains could hydrolyze pork meat proteins. In particular, strain QB7 identified as Staphylococcus simulans had the highest proteolytic activity, was resistant to growth in the presence of 6.5 % NaCl and 150 mg/kg of nitrites, and lacked virulence genes, hemolytic, decarboxylase, DNase, and biofilm-forming activities. Subsequently, S. simulans QB7 was used as a starter in sausage fermentation, which led to an increase in competitiveness of dominant bacteria, reduced growth of undesirable bacteria, higher content of total free fatty acids and free amino acids, and lower pH and water activity values. Thus, S. simulans QB7 can potentially be used as a starter to improve the quality and nutritional properties of fermented meat products.
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Produtos da Carne , Carne de Porco , Coagulase , Peptídeo Hidrolases , ProteóliseRESUMO
Considering the hazards of high salt intake and the current status of research on low-sodium meat products, this study was to analyze the effect of ultrasound combined with glycerol-mediated low-sodium salt curing on the quality of pork tenderloin by analyzing the salt content, water activity (aw), cooking loss, and texture. The results of scanning electron microscope (SEM) analysis, Raman spectroscopy, ultraviolet fluorescence, and surface hydrophobicity were proposed to reveal the mechanism of the effect of combined ultrasound and glycerol-mediated low sodium salt curing on the quality characteristics of pork tenderloin. The results showed that the co-mediated curing could reduce salt content, aw, and cooking loss (p < 0.05), improve texture and enhance product quality. Compared with the control group, the co-mediated curing increased the solubility of the myofibrillar protein, improved the surface hydrophobicity of the protein, increased the content of reactive sulfhydryl groups (p < 0.05), and changed the protein structure. The SEM results showed that the products treated using a co-mediated curing process had a more detailed and uniform pore distribution. These findings provide new insights into the quality of ultrasonic-treated and glycerol-mediated low-salt cured meat products.