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The unprecedented worldwide spread of the Citrus greening disorder, called Huanglongbing (HLB), has urged researchers for rapid interventions. HLB poses a considerable threat to global citriculture owing to its devastating impact on citrus species. This disease is caused by Candidatus Liberibacter species (CLs), primarily transferred through psyllid insects, such as Trioza erytreae and Diaphorina citri. It results in phloem malfunction, root decline, and altered plant source-sink relationships, leading to a deficient plant with minimal yield before it dies. Thus, many various techniques have been employed to eliminate HLB and control vector populations through the application of insecticides and antimicrobials. The latter have evidenced short-term efficiency. While nucleic acid-based analyses and symptom-based identification of the disease have been used for detection, they suffer from limitations such as false negatives, complex sample preparation, and high costs. To address these challenges, secreted protein-based biomarkers offer a promising solution for accurate, rapid, and cost-effective disease detection. This paper presents an overview of HLB symptoms in citrus plants, including leaf and fruit symptoms, as well as whole tree symptoms. The differentiation between HLB symptoms and those of nutrient deficiencies is discussed, emphasizing the importance of precise identification for effective disease management. The elusive nature of CLs and the challenges in culturing them in axenic cultures have hindered the understanding of their pathogenic mechanisms. However, genome sequencing has provided insights into CLs strains' metabolic traits and potential virulence factors. Efforts to identify potential host target genes for resistance are discussed, and a high-throughput antimicrobial testing method using Citrus hairy roots is introduced as a promising tool for rapid assessment of potential treatments. This review summarizes current challenges and novel therapies for HLB disease. It highlights the urgency of developing accurate and efficient detection methods and identifying the complex relations between CLs and their host plants. Transgenic citrus in conjunction with secreted protein-based biomarkers and innovative testing methodologies could revolutionize HLB management strategies toward achieving a sustainable citrus cultivation. It offers more reliable and practical solutions to combat this devastating disease and safeguard the global citriculture industry.
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Citrus , Doenças das Plantas , Citrus/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Animais , Hemípteros/microbiologia , Rhizobiaceae/genética , Rhizobiaceae/patogenicidade , Liberibacter/genética , Folhas de Planta/microbiologia , Frutas/microbiologia , Biomarcadores , Insetos Vetores/microbiologiaRESUMO
Meat and meat products are highly susceptible to the growth of micro-organism and foodborne pathogens that leads to severe economic loss and health hazards. High consumption and a considerable waste of meat and meat products result in the demand for safe and efficient preservation methods. Instead of synthetic additives, the use of natural preservative materials represents an interest. Essential oils (EOs), as the all-natural and green-label trend attributing to remarkable biological potency, have been adopted for controlling the safety and quality of meat products. Some EOs, such as thyme, cinnamon, rosemary, and garlic, showed a strong antimicrobial activity individually and in combination. To eliminate or reduce the organoleptic defects of EOs in practical application, EOs encapsulation in wall materials can improve the stability and antimicrobial ability of EOs in meat products. In this review, meat deteriorations, antimicrobial capacity (components, effectiveness, and interactions), and mechanisms of EOs are reviewed, as well as the demonstration of using encapsulation for masking intense aroma and conducting control release is presented. The use of EOs individually or in combination and encapsulated applications of EOs in meat and meat products are also discussed.
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Anti-Infecciosos , Produtos da Carne , Óleos Voláteis , Óleos Voláteis/farmacologia , Conservantes de Alimentos/farmacologia , Anti-Infecciosos/farmacologia , CarneRESUMO
The production of polycarbonate, a high-performance transparent plastic, employs bisphenol A, which is a prominent endocrine-disrupting compound. Polycarbonates are frequently used in the manufacturing of food, bottles, storage containers for newborns, and beverage packaging materials. Global production of BPA in 2022 was estimated to be in the region of 10 million tonnes. About 65-70% of all bisphenol A is used to make polycarbonate plastics. Bisphenol A leaches from improperly disposed plastic items and enters the environment through wastewater from plastic-producing industries, contaminating, sediments, surface water, and ground water. The concentration BPA in industrial and domestic wastewater ranges from 16 to 1465 ng/L while in surface water it has been detected 170-3113 ng/L. Wastewater treatment can be highly effective at removing BPA, giving reductions of 91-98%. Regardless, the remaining 2-9% of BPA will continue through to the environment, with low levels of BPA commonly observed in surface water and sediment in the USA and Europe. The health effects of BPA have been the subject of prolonged public and scientific debate, with PubMed listing more than 17,000 scientific papers as of 2023. Bisphenol A poses environmental and health hazards in aquatic systems, affecting ecosystems and human health. While several studies have revealed its presence in aqueous streams, environmentally sound technologies should be explored for its removal from the contaminated environment. Concern is mostly related to its estrogen-like activity, although it can interact with other receptor systems as an endocrine-disrupting chemical. Present review article encompasses the updated information on sources, environmental concerns, and sustainable remediation techniques for bisphenol A removal from aquatic ecosystems, discussing gaps, constraints, and future research requirements.
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Ecossistema , Disruptores Endócrinos , Recém-Nascido , Humanos , Águas Residuárias , Monitoramento Ambiental , Água/análise , Compostos Benzidrílicos/análise , Plásticos/química , Disruptores Endócrinos/análiseRESUMO
Heavy metal pollution in water bodies is a global concern. The prominent source of metal contamination in aqueous streams and groundwater is wastewater containing heavy metal ions. Elevated concentrations of heavy metals in water bodies can have a negative impact on water quality and public health. The most effective way to remove metal contaminants from drinking water is thought to be adsorption. A deacetylated derivative of chitin, chitosan, has a wide range of commercial uses since it is biocompatible, nontoxic, and biodegradable. Due to its exceptional adsorption behavior toward numerous hazardous heavy metals from aqueous solutions, chitosan and its modifications have drawn a lot of interest in recent years. Due to its remarkable adsorption behavior toward a range of dangerous heavy metals, chitosan is a possible agent for eliminating metals from aqueous solutions. The review has focused on the ideas of biosorption, its kinds, architectures, and characteristics, as well as using modified (physically and chemically modified) chitosan, blends, and composites to remove heavy metals from water. The main objective of the review is to describe the most important aspects of chitosan-based adsorbents that might be beneficial for enhancing the adsorption capabilities of modified chitosan and promoting the usage of this material in the removal of heavy metal pollutants.
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Quitosana , Metais Pesados , Poluentes Químicos da Água , Purificação da Água , Monitoramento Ambiental , Quitina , Águas Residuárias , AdsorçãoRESUMO
The interactions between various essential oils (EOs) were evaluated for the development of antimicrobial formulations. A full factorial design was applied for testing eight EOs (Mustard, Thyme, Garlic, Oregano, Chinese cinnamon, Cinnamon bark, Red bergamot, Winter savory) against nine bacteria (E.coli O157:H7 RM1239, E.coli O157:H7 RM 1931, E.coli O157:H7 RM 1933, E.coli O157:H7 RM 1934, E.coli O157:H7 380-94, Listeria monocytogenes LM 1045, Listeria innocua ATCC 51742, Salmonella Typhimurium SL 1344, Salmonella enterica Newport ATCC 6962) and two molds (Penicillium chrysogenum ATCC 10106, Aspergillus niger ATCC 1015). Results showed that combinations of Thyme + Oregano, Oregano + Cinnamon bark, Chinese cinnamon + Cinnamon bark have shown high interactions in Factorial design and validated to be mostly additive effects against tested bacteria. The combination of Mustard + Thyme, Mustard + Garlic, and Thyme + Garlic EOs showed high interactions and also all additive effects against tested molds. The corresponding results of Factorial design and checkerboard render the designation to demonstrate the highly efficient formulations and interactions rapidly among abundant mixtures.
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Anti-Infecciosos , Listeria monocytogenes , Óleos Voláteis , Origanum , Anti-Infecciosos/farmacologia , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Listeria , Óleos Voláteis/farmacologiaRESUMO
Stored rice and rice products are prone to contamination by pathogenic fungi and bacteria such as Aspergillus niger, Bacillus cereus, and Paenibacillus amylolyticus. Treatment with antimicrobial essential oils (EOs) and irradiation are options to control spoilage organisms. Microbial samples with or without fumigation with an oregano/thyme EO mixture were irradiated at 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 kGy for calculation of a D10 value. The relative sensitivity was calculated as the ratio of D10 values for the irradiation plus oregano and thyme EO combination and irradiation alone treatments. In all cases, irradiation plus fumigation with the oregano and thyme EO mixture showed increased efficacy compared with irradiation alone. The relative sensitivity of γ-ray irradiation against A. niger was 1.22, 1.33, and 1.24 for radiation dose rates of 10.445, 4.558, and 0.085 kGy/h, respectively, however against B. cereus it was 1.28, 1.45, and 1.49, and against P. amylolyticus it was 1.35, 1.33, and 1.38, for respective γ-ray irradiation dose rates. The relative sensitivity of X-ray irradiation against A. niger, B. cereus, and P. amylolyticus was 1.63, 1.21, and 1.31, respectively, at the X-ray dose rate of 0.76 kGy/h. The results showed that the relative sensitivity of γ-ray irradiation was higher against the two bacteria than the fungus, whereas X-ray showed higher sensitivity against the fungus than the two bacteria. There was no consistent positive or negative relationship between dose rate and relative sensitivity. The results demonstrated the potential of an oregano and thyme EOs mixture as an antimicrobial agent and its efficacy to increase the radiosensitization of A. niger, B. cereus, and P. amylolyticus during γ-ray or X-ray irradiation treatments.
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Irradiação de Alimentos/métodos , Conservação de Alimentos/métodos , Óleos Voláteis/uso terapêutico , Aspergillus niger/efeitos dos fármacos , Aspergillus niger/efeitos da radiação , Bacillus cereus/efeitos dos fármacos , Bacillus cereus/efeitos da radiação , Raios gama , Origanum , Oryza/microbiologia , Paenibacillus/efeitos dos fármacos , Paenibacillus/efeitos da radiação , Radiossensibilizantes/farmacologia , Radiometria , Thymus (Planta) , Raios XRESUMO
Shiga toxin-producing Escherichia coli O157:H7, one of the most severe human foodborne pathogens, can withstand several stresses, including some levels of γ-irradiation. In this study, the response of E. coli O157:H7 to a sensitization irradiation dose of 0.4 kGy was assessed using RNA-seq transcriptomic at 10 (t10) and 60 (t60) min post-irradiation, combined with an isobaric tags for relative and absolute quantitation (iTRAQ) proteomic analysis at 60 min post-irradiation. Several functions were induced by the treatment, such as base excision repair and nucleotide excision repair pathways; sulfur and histidine metabolism, and virulence mechanisms. Additionally, the sulA gene, coding for the cell division repressor, together with other genes involved in SOS response and repair mechanism (including recA, recN, recJ, recQ, mutM and uvrB) were up-regulated at t60. As the early response to irradiation stress (t10), dnaK, groEL, ibpA, sulfur metabolism genes, as well as those related to oxidative stress were up-regulated, while histidine biosynthesis genes were down-regulated. Acid stress, heat shock, UV resistance and several virulence genes, especially stx2A/stx2b which code for the Shiga toxins characteristic of O157:H7, were upregulated at 60 min post-irradiation. The treatment was also found to increase the levels of CysN, MutM, DinG and DnaC in the cells, proteins involved respectively in sulfur metabolism, base excision repair, recombinational DNA repair and chromosome replication. Our results provide insights into the resistance response of E. coli O157:H7 to a non-lethal irradiation dose. Our findings indicate that E. coli O157:H7 can resist to γ-irradiation through important modifications in genes expression and proteins profiles.
Assuntos
Reparo do DNA , Escherichia coli O157 , Proteínas de Escherichia coli , Escherichia coli O157/genética , Proteínas de Escherichia coli/genética , Nucleotídeos , ProteômicaRESUMO
The checkerboard method was used to study the potential interactions between eight essential oils (Basil, Cinnamon, Eucalyptus, Mandarin, Oregano, Peppermint, Tea tree, and Thyme) when used as antibacterial agents against Bacillus cereus LSPQ 2872 and Paenibacillus amylolyticus ATCC 9995. The minimum inhibitory concentration (MIC) of each essential oil (EO) and the fractional inhibitory concentration (FIC) index for the binary combinations of essential oils (EOs) were determined. According to FIC index values, some of the compound binary combinations showed an additive effect; however, Thyme/Tea tree and Cinnamon/Thyme EOs exhibited a synergistic effect against P. amylolyticus and B. cereus, respectively. Cinnamon/Thyme EOs mixture exhibited no interactive effect against P. amylolyticus, but a synergistic effect against B. cereus. The combination of Oregano/Thyme EOs displayed the best antibacterial activity and showed a synergistic effect against B. cereus and P. amylolyticus bacteria. The Oregano/Thyme EOs mixture has potential application in food preservation to reduce the contamination of B. cereus and P. amylolyticus.
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Bacillus cereus/efeitos dos fármacos , Paenibacillus/efeitos dos fármacos , Óleos de Plantas/farmacologia , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Cinnamomum zeylanicum/metabolismo , Sinergismo Farmacológico , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Testes de Sensibilidade Microbiana , Origanum/metabolismo , Thymus (Planta)/metabolismoRESUMO
The antimicrobial activity of sulfur nanoparticles (SNPs) was compared with elemental sulfur and sulfur-containing salts (sodium thiosulfate and sodium metabisulfite) against bacteria (Escherichia coli, Staphylococcus aureus) and fungi (Aspergillus flavus, Candida albicans) using the paper disc, broth microdilution, and time-kill assay methods. The results of the paper disc and MIC tests showed stronger antimicrobial activity of SNPs compared to the elemental sulfur and sulfur-containing salts. SNPs showed more potent activity against bacteria than fungi. Among the test microorganisms, E. coli (Gram-negative) was the most susceptible to SNPs, followed by S. aureus (Gram-positive), C. albicans (yeast), and A. flavus (mold). Scanning electron micrographs of microorganisms treated with SNPs showed different cell disruption patterns depending on the type of microorganisms.
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Antibacterianos/farmacologia , Antifúngicos/farmacologia , Aspergillus flavus/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Enxofre/farmacologia , Quitosana/farmacologia , Testes de Sensibilidade Microbiana , Nanopartículas , Sulfitos/farmacologia , Tiossulfatos/farmacologiaRESUMO
Nanocellulose materials are derived from cellulose, the most abundant biopolymer on the earth. Nanocellulose have been extensively used in the field of food packaging materials, wastewater treatment, drug delivery, tissue engineering, hydrogels, aerogels, sensors, pharmaceuticals, and electronic sectors due to their unique chemical structure and excellent mechanical properties. On the other hand, metal and metal oxide nanoparticles (NP) such as Ag NP, ZnO NP, CuO NP, and Fe3O4 NP have a variety of functional properties such as UV-barrier, antimicrobial, and magnetic properties. Recently, nanocelluloses materials have been used as a green template for producing metal or metal oxide nanoparticles. As a result, multifunctional nanocellulose/metal or metal oxide hybrid nanomaterials with high antibacterial properties, ultraviolet barrier properties, and mechanical properties were prepared. This review emphasized recent information on the synthesis, properties, and potential applications of multifunctional nanocellulose-based hybrid nanomaterials with metal or metal oxides such as Ag NP, ZnO NP, CuO NP, and Fe3O4 NP. The nanocellulose-based hybrid nanomaterials have huge potential applications in the area of food packaging, biopharmaceuticals, biomedical, and cosmetics.
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Celulose/química , Nanopartículas Metálicas/química , Metais/química , Óxidos/química , HumanosRESUMO
The present study was focused on the preparation of gold, silver, and gold-silver-alloy nanoparticles using Rhodomyrtus tomentosa acetone extract (RAE). The synthesized nanoparticles showed the surface plasmon resonance absorption peak corresponding to gold and silver nanoparticle. However, Au-Ag-Alloy nanoparticles showed the single peak between the peaks of AuNPs and AgNPs. TEM observation ascertained the shape and size of nanoparticles. FTIR results indicated the involvement of RAE for the synthesis and capping of nanoparticles. Study on antibacterial activity demonstrated the enhanced activity of RAE capped on silver and Au-Ag-Alloy nanoparticles against Escherichia coli.
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Acetona/química , Antibacterianos/química , Escherichia coli/efeitos dos fármacos , Nanopartículas Metálicas/química , Extratos Vegetais/farmacologia , Traqueófitas/química , Antibacterianos/farmacologia , Combinação de Medicamentos , Sinergismo Farmacológico , Ouro/química , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Extratos Vegetais/administração & dosagem , Prata/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Silver nanoparticles (Ag-NPs) were synthesized using banana powder as a reducing and stabilizing agent, and banana/Ag-NPs composite films with different concentration of Ag-NPs were prepared simultaneously. The composite films were yellowish brown and exhibited characteristic plasmon resonance peak of Ag-NPs at 430 nm. The optical, mechanical, water vapor barrier, thermal stability, and antimicrobial properties of the composite films were greatly influenced by the concentration of Ag-NPs. The composite film with a silver concentration of 1.0 mM demonstrated the highest tensile strength, thermal stability, transparency, and water contact angle with the lowest water vapor permeability (1.36 ± 0.10 × 10-9 g m/m2 Pa s). Also, the composite films incorporated with 1.0 mM of Ag-NPs exhibited a strong antibacterial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) food-borne pathogenic bacteria.
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This study illustrates a facile strategy for efficient immobilization of enzymes on a metal nanoparticle surface. The strategy proposed here enables the enzymatic activity to be retained while increasing the enzyme thermostability. It is demonstrated that the use of a zwitterionic amino acid tyrosine as a reducing and capping agent to synthesise gold nanoparticles allows efficient immobilization of phytase enzyme through charge-switchable electrostatic interactions. The detailed kinetic and thermodynamic studies reveal that the proposed enzyme immobilization strategy improves the overall quality of phytase by reducing the activation energy required for substrate hydrolysis and broadening the temperature window in which immobilized enzyme is able to operate. The outcomes of this study indicate that the underlying zwitterionic nature of 20 natural amino acids along with significant variability in their isoelectric points and hydropathy indices as well the ability of some of the amino acids to reduce metal ions is likely to offer significant opportunities for tailoring nano-bio interfaces in a rational manner for a range of biological applications.
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6-Fitase/química , Ouro/química , Nanopartículas Metálicas/química , 6-Fitase/metabolismo , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Temperatura , TermodinâmicaRESUMO
Retention of total activity of the subtilisin-like serine protease from Beauveria sp. MTCC 5184 (Bprot) in the vicinity of (1) 3 M GdnHCl for 12 h, (2) 50% methanol and dimethyl sulfoxide each for 24 h, and (3) proteolytic enzymes (trypsin, chymotrypsin, and proteinase K) for 48 h led to expect the enzyme to be a kinetically stable protein. Also, the structure of the protein was stable at pH 2.0. Biophysical characterization and conformational transitions were monitored using steady-state and time-resolved fluorescence, FTIR, and CD spectroscopy. Single tryptophan in the protein exists as two conformers, in hydrophobic and polar environment. The secondary structure of Bprot was stable in 3 M GdnHCl as seen in far-UV CD spectra. The active fraction of Bprot obtained from size-exclusion chromatography in the presence of GdnHCl (1.0-3.0 M) eluted at reduced retention time. The peak area of inactive or denatured protein with the same retention time as that of native protein increased with increasing concentration of denaturant (1.0-4.0 M GdnHCl). However, the kinetics of GdnHCl-induced unfolding as studied from intrinsic fluorescence revealed k unf of native protein to be 5.407 × 10(-5) s(-1) and a half-life of 3.56 h. The enzyme is thermodynamically stable in spite of being resistant to the denaturant, which could be due to the effect of GdnHCl imparting rigidity to the active fraction and simultaneously unfolding the partially unfolded protein that exists in equilibrium with the folded active protein. Thermal and pH denaturation of Bprot exhibited interesting structural transitions.
Assuntos
Beauveria/enzimologia , Subtilisina/química , Subtilisina/metabolismo , Estabilidade Enzimática/efeitos dos fármacos , Guanidina/farmacologia , Concentração de Íons de Hidrogênio , Cinética , Conformação Proteica , Desnaturação Proteica/efeitos dos fármacos , Proteólise , Solventes/farmacologia , TemperaturaRESUMO
Arsenic contamination of groundwater in different parts of the world is an outcome of natural and/or anthropogenic sources, leading to adverse effects on human health and ecosystem. Millions of people from different countries are heavily dependent on groundwater containing elevated level of As for drinking purposes. As contamination of groundwater, poses a serious risk to human health. Excessive and prolonged exposure of inorganic As with drinking water is causing arsenicosis, a deteriorating and disabling disease characterized by skin lesions and pigmentation of the skin, patches on palm of the hands and soles of the feet. Arsenic poisoning culminates into potentially fatal diseases like skin and internal cancers. This paper reviews sources, speciation, and mobility of As and global overview of groundwater As contamination. The paper also critically reviews the As led human health risks, its uptake, metabolism, and toxicity mechanisms. The paper provides an overview of the state-of-the-art knowledge on the alternative As free drinking water and various technologies (oxidation, coagulation flocculation, adsorption, and microbial) for mitigation of the problem of As contamination of groundwater.
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Intoxicação por Arsênico/epidemiologia , Arsênio/toxicidade , Água Potável/química , Água Subterrânea/química , Dermatopatias/epidemiologia , Poluentes Químicos da Água/toxicidade , Adsorção , Arsênio/análise , Monitoramento Ambiental , Filtração , Floculação , Humanos , Prevalência , Risco , Dermatopatias/induzido quimicamente , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Abastecimento de Água/análiseRESUMO
This study looked at using modified camelina oil to develop sustainable coatings that could replace those derived from petroleum-based materials for use in packaging and other industrial sectors. Solvent-free synthesis of maleic anhydride grafted camelina oil (MCO) was carried out at two different temperatures (200 and 230 °C) to obtain sustainable hydrophobic coating materials for paper substrates. Maleic anhydride grafting of camelina oil was confirmed with attenuated total reflectance-Fourier transform infrared and NMR spectroscopic techniques, and up to 16% grafting of maleic anhydride was achieved, as determined by the titration method. MCO, obtained at different reaction temperatures, was coated onto cellulosic paper and evaluated for its hydrophobicity, mechanical, oxygen, and water vapor barrier properties. Scanning electron microscopy indicated the homogeneous dispersion of coating material onto the paper substrate. MCO-coated papers (MCO-200C paper and MCO-230C paper) provided a water contact angle of above 90° which indicates that the modified oil was working as a hydrophobic coating. Water vapor permeability (WVP) testing of coated papers revealed a reduction in WVP of up to 94% in comparison to the uncoated paper. Moreover, an improved oxygen barrier property was also observed for paper coated with both types of MCO. Analysis of the mechanical properties showed a greater than 70% retention of tensile strength and up to a five-fold increase in elongation at break of coated versus uncoated papers. Overall, the results show that camelina oil, a renewable resource, can be modified to produce environmentally friendly hydrophobic coating materials with improved mechanical and water vapor barrier properties that can serve as a potential coating material in the packaging industry. The results of this research could find applications in the huge paper packaging industries, specially in food packaging.
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BACKGROUND: Age is one of the most critical identifiers for both living and dead. Forensic professionals in medical and legal matters are often presented with dismembered, disfigured, putrefied, or skeletal remains for analysis. In such situations, it is essential to identify individuals and estimate their ages. The skull is typically the well-preserved part of the body in such situations. If an aged person needs their age officially established for employment, superannuation, pension settlements, senior citizen benefits, etc., they may turn to medical professionals for help in making that determination. It has always been controversial to use cranial suture obliteration as a reference for age. Different geographical locations have been shown to have vastly different patterns of cranial suture closure. Therefore, this study was conceptualized to assess cranial vault suture obliteration in relation to age in the Meo population. This study was conducted to determine whether obliteration of cranial sutures can be taken into account for the estimation of age in elderly in this region and its reliability along with the influence of other factors such as sex and right and left side differences. MATERIALS AND METHODS: A total of 100 cases of more than 20 years of age brought for medicolegal autopsy were analyzed. The coronal, sagittal, and lambdoid sutures were studied ectocranially and endocranially. The degree of obliteration of sutures was scored ectocranially as well as endocranially. Data were analyzed using IBM SPSS Statistics for Windows, Version 21 (Released 2012; IBM Corp., Armonk, New York, United States). Descriptive statistics were evaluated for continuous data in terms of mean and standard deviation, and categorical data were presented by frequency and percentages. An independent t-test was applied to find out the mean difference between the right and left sides of suture closure for ectocranial and endocranial surfaces. The Spearman rank correlation test was carried out to find out the relationship between the age and score of suture closure both ectocranially and endocranially. RESULT: Ectocranially and endocranially, the overall sagittal suture obliterates early followed by coronal sutures and then lambdoid sutures. On comparing the mean ectocranial and mean endocranial scores of 100 subjects by applying an independent t-test, a highly significant difference was observed in all three sutures. On correlating ectocranial sutures and endocranial sutures and age at death in all the cases through sagittal, right and left coronal, and lambdoid by applying the Spearman rank correlation coefficient, a highly significant correlation was found in all the subjects combined (p-value 0.000). However, no significant correlation (p-value >0.05) was found in ectocranial and endocranial sagittal sutures in individual age groups. CONCLUSION: We concluded that obliteration on the endocranial surface is more reliable than on the ectocranial surface. No statistically significant difference exists on the obliteration of sutures on the right and left sides of coronal and lambdoid sutures. The lapsed union was evident in all three sutures ectocranially. Endocranial suture obliteration can be used as a corroborative tool for age estimation.
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A low-density polyethylene (LDPE) film reinforced with cellulose nanocrystals (CNCs) with an encapsulated bioactive formulation (cinnamon essential oil + silver nanoparticles) was developed for preservation of fresh strawberries. Antimicrobial activity of the active LDPE films was tested against Escherichia coli O157:H7, Salmonella typhimurium, Aspergillus niger, and Penicillium chrysogenum by agar volatilization assay. The optimal condition of the films showed ≥75% inhibitory capacity against the tested microbes. Strawberries were stored with different types of films: Group 1 (control): (LDPE + CNCs + Glycerol), Group 2: (LDPE + CNCs + Glycerol + AGPPH silver nanoparticles), Group 3: (LDPE + CNCs + Glycerol + cinnamon), Group 4: (LDPE + CNCs + Glycerol + active formulation), and Group 5: (LDPE + CNCs + Glycerol + active formulation + 0.5 kGy γ-radiation) at 4°C for 12 days. Weight loss (WL) (%), decay (%), firmness (N), color, and total phenolics and anthocyanin content of the strawberries were measured. Results showed that the most effective LDPE-nanocomposite film for reducing the microbial growth was LDPE + CNCs + Glycerol + active formulation film (Group 4). When combined with γ-irradiation (0.5 kGy), the LDPE + CNCs + Glycerol + active formulation (Group 5) significantly reduced both decay and WL by 94%, as compared to the control samples after 12 days of storage. Total phenols (from 952 to 1711 mg/kg) and anthocyanin content (from 185 to 287 mg/kg) increased with storage time under the different treatments. The mechanical properties, water vapor permeability (WVP), and surface color of the films were also tested. Though the WVP of the films were not influenced by the types of antimicrobial agents, they did significantly (p ≤ 0.05) change color and mechanical properties of the films. Therefore, combined treatment of active film and γ-irradiation has potential as an alternative method for extending the shelf-life of storage strawberries while maintaining fruit quality. PRACTICAL APPLICATION: Bioactive Low-density polyethylene (LDPE) nanocomposite film was developed in the study by incorporating active formulation (essential oil and silver nanoparticle) to extend the shelf life of stored strawberries. The bioactive LDPE-based nanocomposite film along with γ-irradiation could be used to preserve fruits for long-term storage by controlling the growth of foodborne pathogenic bacteria and spoilage fungi.
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Fragaria , Nanopartículas Metálicas , Nanocompostos , Óleos Voláteis , Polietileno , Embalagem de Alimentos/métodos , Prata/farmacologia , Antocianinas/farmacologia , Glicerol , Óleos Voláteis/farmacologia , Nanocompostos/química , Expectativa de VidaRESUMO
This study utilized post-industrial wheat starch (biological macromolecule) for the development of poly(butylene adipate-co-terephthalate) (PBAT) based thermoplastic starch blend (TPS) and biocomposite films. PBAT (70 wt%) was blended with plasticized post-industrial wheat starch (PPWS) (30 wt%) and reinforced with talc master batch (MB) (25 wt%) using a two-step process, consisting of compounding the blend for pellet preparation, followed by the cast film extrusion at 160 °C. The effect of the chain extender was analyzed at compounding temperatures of 160 and 180 °C for talc-based composites. The incorporation of talc MB has increased the thermal stability of the biocomposites due to the nucleating effect of talc. Moreover, tensile strength and Young's modulus increased by about 5 and 517 %, respectively as compared with the TPS blend film without talc MB. Thermal, rheological, and morphological analyses confirmed that the use of talc in the presence of chain extender at a processing temperature of 160 °C has resulted in an enhanced dispersion of talc and chain entanglement with PBAT and PPWS than PBAT/PPWS blend and PBAT/PPWS/Talc composite films. On the other hand, at 180 °C, the talc-containing biocomposite with chain extender tended to form PPWS agglomerates, thereby weakening its material properties.
Assuntos
Poliésteres , Talco , Amido , Resistência à Tração , TemperaturaRESUMO
Active food packaging (AP) is an innovative technology, which provides a new system for food preservation in the food industry. The growing need towards consumer demands and market trends inspires researchers and food industries to employ AP. The advent of nanotechnology has had a significant impact on AP applications due to its distinctive physicochemical and biological properties. The incorporation of nano-sized materials into the polymer matrix has greatly improved the thermal, mechanical, gas barrier properties and compostability of biopolymers, thereby overcoming the shortcomings of bio-based film packaging. One of the great features of nano-sized materials is that they can act as release-controlling devices for active compounds in AP. The current review summarized the impact of nano-sized materials in the physical properties of the bio-based packaging films and their potential utilization and applications in AP. The safety concentrations of nano-sized materials and their possible migration from food packaging into food were also reviewed to gain a perspective view on their utilization in AP.