31 research outputs found

    Electrospun nanosystems based on PHBV and ZnO for ecological food packaging

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    The electrospun nanosystems containing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and 1 wt% Fe doped ZnO nanoparticles (NPs) (with the content of dopant in the range of 0–1 wt% Fe) deposited onto polylactic acid (PLA) film were prepared for food packaging application. They were investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), antimicrobial analysis, and X-ray photoelectron spectrometry (XPS) techniques. Migration studies conducted in acetic acid 3% (wt/wt) and ethanol 10% (v/v) food simulants as well as by the use of treated ashes with 3% HNO3 solution reveal that the migration of Zn and Fe falls into the specific limits imposed by the legislation in force. Results indicated that the PLA/PHBV/ZnO:Fex electrospun nanosystems exhibit excellent antibacterial activity against the Pseudomonas aeruginosa (ATCC-27853) due to the generation of a larger amount of perhydroxyl (¿OOH) radicals as assessed using electron para-magnetic resonance (EPR) spectroscopy coupled with a spin trapping method. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Innovation and entrepreneurship as strategies for success among Cuban-based firms in the late years of the transatlantic slave trade

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    This article examines how Cuban-based firms and entrepreneurs circumvented ever- increasing risks in the illegal slave trade. The article sheds light to this question by analyzing new qualitative information of 65 Cuban-based firms against the Slavevoyages database. Our findings indicate that Cuban-based firms were entrepreneurial as they exploited the opportunities arising from the volatility of the slave trade by: (a) internalizing networks of agents which allowed the rapid diffusion of information, (b) diversifying trading goods and expanding the number of partnerships to reduce transaction costs and risk, and (c) adopting technological innovations that modified the design and use of vessels

    Determination Of Uv Stabilizers In Pet Bottles By High Performance-size Exclusion Chromatography.

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    A Size Exclusion Chromatography-High Performance Liquid Chromatography (SECHPLC) method to determine antioxidants and UV stabilizers in PET bottles has been developed. In only a single run a synthetic mixture of the stabilizers was separated and quantified. The detection limit obtained for BHT, Tinuvin 326, Cyasorb UV 5411, and Tinuvin P was about 0.1 microgram/g and for Irgafos 168 it was 1.0 microgram. RSD values were lower than 3%. Tinuvin P was identified and quantified in PET bottle extracts. Olive oil, soybean oil and sunflower oil showed well defined separation from Tinuvin P at the same conditions of analysis. Cyclic dimers were identified in the PET extracts.13575-8

    Developing ethyl lauroyl arginate antimicrobial films to combat Listeria monocytogenes in cured ham

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    Widespread use of plastics poses a serious environmental hazard to our planet and should be substituted by eco-friendly and biodegradable alternatives, simultaneously reducing waste of perishable food products and the risk of transmission of pathogenic microbes. In our study, we describe how the water solubility of the antimicrobial surfactant ethyl lauroyl arginate (LAE) can be reduced through complexation with a Keggin-type polyoxometalate (POM), K8[SiW11O39]. The POM-LAE complex, LAE7K[SiW11O39], was effective against Listeria monocytogenes (L. monocytogenes) and Escherichia coli (E. coli) with minimal inhibitory concentrations (MICs) of 32 and 64 μg/mL, respectively, with the important finding that the concentrations of LAE required to inhibit bacterial growth were as much as two times lower in the POM-LAE complex, compared with LAE on its own. In addition, our results demonstrate that POM-LAE is both an effective inhibitor of biofilm formation and is also able to destroy pre-formed biofilms of L. monocytogenes and E. coli at MIC concentrations. Further, POM-LAE was incorporated into carboxymethyl cellulose (CMC) films that were able to reduce 7–8 log (CFU/mL) of L. monocytogenes at concentrations of 5–10% POM-LAE. In vivo assays of the POM-LAE-CMC films with cured ham prevented initialk bacterial growth with a 0.77 log significative reduction in bacterial counts. Overall, this work provides new alternatives for the development of antimicrobial biodegradable films for ready-to-eat (RTE) foods prone to contamination with pathogenic bacteria, such as L. monocytogenes, while also circumventing practical issues related to the incorporation of LAE into active packaging films.This work was supported by the Spanish Ministerio de Ciencia e Innovación (RTI2018-097805-B-I00 and PID2019-109333RB-I00), the Gobierno de Aragón (Project LMP49-18) and the Centre for the Development of Industrial Technology (1061/2020). N.G. acknowledges a fellowship from the Universidad de Zaragoza and Université de Pau et des Pays de l’Adour.Peer reviewe

    Migration of residual nonvolatile and inorganic compounds from recycled post-consumer PET and HDPE

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    Migration of nonvolatile and inorganic residual compounds from post-consumer recycled polyethylene terephthalate (PET) submitted to cleaning processes for subsequent production of materials intended to food contact, as well as from multilayer packaging material containing post-consumer recycled high-density polyethylene (HDPE) was determined. Tests were carried out using food simulants. Nonvolatile organic contaminants from PET, determined by liquid chromatography-mass spectrometry (UPLC-QqQ/MS), showed significant migration reduction as consequence of the more complex cleaning technologies applied. However, contaminants not allowed by Brazilian and European Union regulations were identified even in deep cleaning samples. Results from multilayer HDPE showed a greater number of contaminants when compared to recycled pellets. Inorganic contaminants, determined by inductively coupled plasma mass spectrometry were below the acceptable levels. Additional studies for identification and quantitation of unknown molecules which were not possible to identify in this study by UPLC-QqQ/MS are required to ascertain the safety of using post-consumer recycled packaging material254686696CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES303670/2010-023038.003966/2013-08Foi determinada a migração de compostos residuais não voláteis e de inorgânicos provenientes do polietileno tereftalato (PET) pós-consumo reciclado, submetido a processos de descontaminação para produção de materiais destinados a contato com alimentos, bem como de material de embalagem multicamada contendo polietileno de alta densidade (HDPE) pós-consumo reciclado. Os ensaios foram realizados utilizando simulantes de alimentos. Os contaminantes orgânicos não voláteis do PET, determinados por cromatografia líquida-espectrometria de massas (UPLC-QqQ/MS), apresentaram redução significativa da migração como consequência da complexidade da tecnologia de descontaminação aplicada. No entanto, contaminantes não permitidos pelas legislações brasileira e europeia foram identificados, mesmo em amostras submetidas à tecnologia mais complexa. Os resultados do HDPE multicamadas mostraram maior número de contaminantes quando em comparação aos peletes reciclados. Os níveis de contaminantes inorgânicos, determinados por espectrometria de massa com fonte de plasma, se mostraram abaixo dos níveis recomendados. Estudos adicionais para identificar e quantificar as estruturas moleculares não identificadas neste estudo por UPLC-QqQ/MS são necessários para garantir a segurança do uso de material de embalagem pós-consumo reciclad

    Migration of Residual Nonvolatile and Inorganic Compounds from Recycled Post-Consumer PET and HDPE

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    Migration of nonvolatile and inorganic residual compounds from post-consumer recycled polyethylene terephthalate (PET) submitted to cleaning processes for subsequent production of materials intended to food contact, as well as from multilayer packaging material containing post-consumer recycled high-density polyethylene (HDPE) was determined. Tests were carried out using food simulants. Nonvolatile organic contaminants from PET, determined by liquid chromatography-mass spectrometry (UPLC-QqQ/MS), showed significant migration reduction as consequence of the more complex cleaning technologies applied. However, contaminants not allowed by Brazilian and European Union regulations were identified even in deep cleaning samples. Results from multilayer HDPE showed a greater number of contaminants when compared to recycled pellets. Inorganic contaminants, determined by inductively coupled plasma mass spectrometry were below the acceptable levels. Additional studies for identification and quantitation of unknown molecules which were not possible to identify in this study by UPLC-QqQ/MS are required to ascertain the safety of using post-consumer recycled packaging material
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