101 results on '"Cerqueira MA"'
Search Results
2. El programa común complementario
- Author
-
Fornells, Josep Mª, Sans, Mª Antonia, Cerqueira, Mª Josep, and Hernández, Salvador
- Published
- 2005
3. El programa común complementario
- Author
-
Fornells, Josep Mª, primary, Sans, Mª Antonia, additional, Cerqueira, Mª Josep, additional, and Hernández, Salvador, additional
- Published
- 2005
- Full Text
- View/download PDF
4. Acidentes de trabalho atendidos em serviço de emergência
- Author
-
Conceição Paulo Sérgio de Andrade, Nascimento Itatyane Bispo de Oliveira, Oliveira Patrícia Silva, and Cerqueira Maria Ruth Moreira
- Subjects
Acidentes de Trabalho ,Emergências ,Estudos Transversais ,Sub-Registro ,Medicine ,Public aspects of medicine ,RA1-1270 - Abstract
No Brasil, acidentes de trabalho (AT) são notificados apenas para a Previdência Social, restringindo-se, portanto, aos trabalhadores com carteira assinada, que representam, atualmente, menos da metade da força de trabalho ocupada. Neste estudo transversal, pretende-se descrever os acidentes de trabalho e estimar a sua freqüência dentre os casos atendidos num serviço de emergência de Salvador, Bahia, Brasil. Identificou-se 215 pessoas atendidas por causas externas, das quais 68 (31,6%) eram AT. Verificou-se que 36,8% dos acidentados tinham carteira assinada, e dentre esses, apenas 45,5% tiveram notificação para a Previdência, o que indica o alto nível de sub-registro dos AT, mesmo entre os trabalhadores do setor formal. Registros de serviços de emergência podem ser importante fonte de informação dos acidentes de trabalho, e a extensão das ações de vigilância para estes locais poderá ser um passo importante para um melhor conhecimento da magnitude de ocorrência desses eventos na população.
- Published
- 2003
5. Sensitized photooxygenation of Ent-Pimaradiene derivatives
- Author
-
Cruz Frederico G., Cerqueira Martins D. de, and Roque Nídia F.
- Subjects
diterpenes ,ent-pimaradiene derivatives ,singlet oxygen ,photooxygenation ,Chemistry ,QD1-999 - Abstract
Methyl esters of diterpenoids ent-pimara-9(11),15-dien-19-oic acid (1), ent-pimara-7,15-dien-19-oic acid (2), and ent-pimara-8,15-dien-19-oic acid (3) were submitted to photooxygenation reactions with sensitized singlet oxygen. While compounds 2 and 3 were converted to the products, compound 1 reacted only partially, suggesting an influence of the steric hindrance on the endocyclic double bond of 1. The oxidation products obtained, methyl-7alpha,11beta-dihydroxypimara-8,15-dien-19-oate (5), methyl-7alpha-hydroperoxypimara-8(14),15-dien-19 oate (6), methyl-7alpha-hydroxy-14-oxopimara-15-en-19-oate (8), methyl-7alpha,9alpha-dihydroxypimara-8(14),15-dien-19-oate (9) and methyl-7alpha,14alpha-dihydroxypimara-8,15-dien-19-oate (10), are new and their structures were elucidated by spectral data analysis.
- Published
- 2003
6. O processo de distritalização e a utilização de serviços de saúde - avaliação do caso de Pau da Lima, Salvador, Bahia, Brasil
- Author
-
Silva Lígia Maria V. da, Formigli Vera Lúcia A., Cerqueira Macius P., Kruchevsky Leonardo, Teixeira Márcia Maria A., Barbosa Antonio Sergio M., Conceição Paulo Sergio de A., Khouri Mauro de A., and Nascimento Carlito L.
- Subjects
Serviços de Saúde ,Descentralizado ,Serviços Privados de Saúde ,Saúde Pública ,Medicine ,Public aspects of medicine ,RA1-1270 - Abstract
Foi realizado estudo transversal de utilização de serviços de saúde no Distrito Sanitário de Pau da Lima, Salvador, Bahia, Brasil, em 1992, a partir de inquérito domiciliar com recurso à técnica de amostragem por conglomerados. Entre as 1887 pessoas moradoras dos 384 domicílios visitados, 236 haviam utilizado serviços de saúde nos últimos 30 dias, correspondendo à taxa global de utilização de 12,5%. Os serviços públicos do distrito foram responsáveis por 25,9% do total dos atendimentos, tendo ocorrido maior utilização na faixa etária entre 15 e 29 anos (29,8%) e no sexo feminino (73,7%). A escolha do tipo de serviços foi influenciada principalmente por razões relacionadas com a acessibilidade (63,7%). A procura dos serviços decorreu sobretudo de motivos relacionados com a ocorrência de doença e com a busca de serviços curativos (75,7%). Esses achados revelam incipiência no processo de distritalização, expresso tanto em insuficiências quantitativas relacionadas com a cobertura assistencial e a oferta de serviços, quanto em problemas organizacionais que fazem com que a produção ainda não utilize preferencialmente os serviços do Distrito. Os autores discutem esses resultados no atual contexto de expansão do setor privado e de colapso de financiamento setorial.
- Published
- 1995
7. Prevention, control, and elimination of neglected diseases in the Americas: Pathways to integrated, inter-programmatic, inter-sectoral action for health and development
- Author
-
Genovese Miguel A, Ippolito-Shepherd Josefa, Cerqueira Maria, Vasquez Javier, Rojas Rocio, Ault Steven K, Ehrenberg John P, Holveck John C, and Periago Mirta
- Subjects
Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background In the Latin America and Caribbean region over 210 million people live below the poverty line. These impoverished and marginalized populations are heavily burdened with neglected communicable diseases. These diseases continue to enact a toll, not only on families and communities, but on the economically constrained countries themselves. Discussion As national public health priorities, neglected communicable diseases typically maintain a low profile and are often left out when public health agendas are formulated. While many of the neglected diseases do not directly cause high rates of mortality, they contribute to an enormous rate of morbidity and a drastic reduction in income for the most poverty-stricken families and communities. The persistence of this "vicious cycle" between poverty and poor health demonstrates the importance of linking the activities of the health sector with those of other sectors such as education, housing, water and sanitation, labor, public works, transportation, agriculture, industry, and economic development. Summary The purpose of this paper is three fold. First, it focuses on a need for integrated "pro-poor" approaches and policies to be developed in order to more adequately address the multi-faceted nature of neglected diseases. This represents a move away from traditional disease-centered approaches to a holistic approach that looks at the overarching causes and mechanisms that influence the health and well being of communities. The second objective of the paper outlines the need for a specific strategy for addressing these diseases and offers several programmatic entry points in the context of broad public health measures involving multiple sectors. Finally, the paper presents several current Pan American Health Organization and other institutional initiatives that already document the importance of integrated, inter-programmatic, and inter-sectoral approaches. They provide the framework for a renewed effort toward the efficient use of resources and the development of a comprehensive integrated solution to neglected communicable diseases found in the context of poverty, and tailored to the needs of local communities.
- Published
- 2007
- Full Text
- View/download PDF
8. Protective fibrous structures based on cellulose fibers functionalized with metal oxide nanoparticles by electrospinning and electrospray deposition.
- Author
-
Araújo JC, Silva PM, Cerqueira MA, Teixeira P, Tira-Picos V, Neto P, Soares OSGP, Graça CL, Fangueiro R, and Ferreira DP
- Abstract
This work aims to develop a bio-based fibrous material that is able to adsorb and degrade chemical and biological hazardous agents. Thus, cellulosic fabrics (flax) were functionalized with chitosan (CS) and poly(ethylene oxide) (PEO) electrospun nanofibers doped with titanium dioxide (TiO
2 ) and cerium dioxide (CeO2 ) nanoparticles (NPs). The electrospray deposition of these NPs was also tested. The TiO2 NPs were synthesized using a very straightforward precipitation method. The successful synthesis was confirmed by Scanning Transmission Electron Microscopy (STEM) and Attenuated Total Reflectance-Fourier-Transform Infrared Spectroscopy (ATR-FTIR). The functionalization of the fabrics with the NPs and the nanofibers doped with NPs was proved by Field Emission Scanning Electron Microscopy (FESEM), ATR-FTIR, and Ground-State Diffuse Reflectance (GSDR). The developed samples presented antibacterial activity against Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 434), reaching values of 99.97 and 100.0 %, respectively. The degradation of methylene blue (MB) and dimethyl methylphosphonate (DMMP) was evaluated. The best samples were able to decompose 97.82 % of DMMP. The wash durability of the nanocoating was also tested. The developed fibrous structures show great potential for personal protection applications., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Diana P. Ferreira reports financial support was provided by Foundation for Science and Technology. Joana C. Araujo reports financial support was provided by Foundation for Science and Technology. Pilar Teixeira reports financial support was provided by Foundation for Science and Technology. Catia L. Graca reports financial support was provided by Foundation for Science and Technology. Olivia Salome G. P. Soares reports was provided by Foundation for Science and Technology. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2024
- Full Text
- View/download PDF
9. Gelatin-chitosan interactions in edible films and coatings doped with plant extracts for biopreservation of fresh tuna fish products: A review.
- Author
-
Eranda DHU, Chaijan M, Panpipat W, Karnjanapratum S, Cerqueira MA, and Castro-Muñoz R
- Abstract
The preservation of tuna fish products, which are extremely perishable seafood items, is a substantial challenge due to their instantaneous spoilage caused by microbial development and oxidative degradation. The current review explores the potential of employing chitosan-gelatin-based edible films and coatings, which are enriched with plant extracts, as a sustainable method to prolong the shelf life of tuna fish products. The article provides a comprehensive overview of the physicochemical properties of chitosan and gelatin, emphasizing the molecular interactions that underpin the formation and functionality of these biopolymer-based films and coatings. The synergistic effects of combining chitosan and gelatin are explored, particularly in terms of improving the mechanical strength, barrier properties, and bioactivity of the films. Furthermore, the application of botanical extracts, which include high levels of antioxidants and antibacterial compounds, is being investigated in terms of their capacity to augment the protective characteristics of the films. The study also emphasizes current advancements in utilizing these composite films and coatings for tuna fish products, with a specific focus on their effectiveness in preventing microbiological spoilage, decreasing lipid oxidation, and maintaining sensory qualities throughout storage. Moreover, the current investigation explores the molecular interactions associated with chitosan-gelatin packaging systems enriched with plant extracts, offering valuable insights for improving the design of edible films and coatings and suggesting future research directions to enhance their effectiveness in seafood preservation. Ultimately, the review underscores the potential of chitosan-gelatin-based films and coatings as a promising, eco-friendly alternative to conventional packaging methods, contributing to the sustainability of the seafood industry., Competing Interests: Declaration of competing interest The author declares no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
10. Strategies for the incorporation of organosolv lignin in hydroxypropyl methylcellulose-based films: A comparative study.
- Author
-
Silva L, Colussi F, Martins JT, Vieira JM, Pastrana LM, Teixeira JA, Cerqueira MA, and Michelin M
- Abstract
Organosolv lignin extracted from vine pruning residues was added to hydroxypropyl methylcellulose (HPMC)-based films using three strategies: i) lignin incorporated into the film (lignin-based film), ii) lignin nanoparticles (LNPs) incorporated into the film (LNPs-based film), and iii) lignin coated on HPMC films' surface (lignin-coated film). The films obtained were evaluated in terms of morphology, water barrier and mechanical properties, and antioxidant capacity. Results showed that LNPs incorporation did not affect the films´ water vapour permeability (WVP). Nonetheless, the lignin-based and lignin-coated films improved the water barrier properties of HPMC-based films, achieving a 31.5 and 36 % reduction of WVP, respectively. The morphological evaluation, performed by scanning electron microscopy, revealed films' morphology changes with the lignin incorporation, which was more evident in the lignin-based films. Fourier transform infrared spectroscopy (FTIR) showed minor changes in the film's structure using the different lignin incorporation methods. The mechanical properties were improved, including a significant increase in the tensile strength in the lignin-based and lignin-coated films. All films showed high radical scavenging activity (RSA) after 24 h, with a gradual increase in the lignin-coated films over time. The lignin-coated films showed to be the most promising incorporation strategy to improve the HPMC-based film's properties., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
11. Ki67 Index Correlates with Tumoral Volumetry and 5-ALA Residual Fluorescence in Glioblastoma.
- Author
-
Sprenger F, da Silva Junior EB, Ramina R, Cavalcanti MS, Martins SB, Cerqueira MA, Falcão AX, and Corrêa de Almeida Teixeira B
- Subjects
- Humans, Middle Aged, Female, Male, Aged, Tumor Burden, Adult, Fluorescence, Glioblastoma diagnostic imaging, Glioblastoma surgery, Glioblastoma pathology, Glioblastoma metabolism, Ki-67 Antigen metabolism, Brain Neoplasms surgery, Brain Neoplasms diagnostic imaging, Brain Neoplasms pathology, Brain Neoplasms metabolism, Magnetic Resonance Imaging methods, Aminolevulinic Acid
- Abstract
Background: Malignant gliomas are the most prevalent primary malignant cerebral tumors. Preoperative imaging plays an important role, and the prognosis is closely related to surgical resection and histomolecular aspects. Our goal was to correlate Ki67 indexes with tumoral volumetry in semiautomatic segmentation on preoperative magnetic resonance images and residual fluorescence in a 5-ALA-assisted resection cohort., Methods: We included 86 IDH-wildtype glioblastoma patients with complete preoperative imaging submitted to 5-ALA assisted resections. Clinical, surgical, and histomolecular findings were also obtained. Preoperative magnetic resonance studies were preprocessed and segmented semiautomatically on Visualization and Analysis for whole tumor (WT) on 3D FLAIR, enhancing tumor (ET), and necrotic core on 3D postgadolinium T1. We performed a linear regression analysis for Ki67 and a multivariate analysis for surgical outcomes., Results: Higher Ki-67 indexes correlated positively with higher WT (P = 0.048) and ET (P = 0.002). Lower Ki67 correlated with 5-ALA free margins (P = 0.045). WT and ET volumes correlated with the extent of resection (EOR; P = 0.002 and 0.002, respectively). Eloquence did not impact EOR (P = 0.14)., Conclusions: There is a correlation between Ki67, the metabolically active tumoral volumes (WT and ET), and 5-ALA residual fluorescence. Methodological inconsistencies are probably responsible for contradictory literature findings, and further prospective studies are needed to validate and reproduce these findings., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
12. Multilayer Film Comprising Polybutylene Adipate Terephthalate and Cellulose Nanocrystals with High Barrier and Compostable Properties.
- Author
-
Melendez-Rodriguez B, Prieto C, Pardo-Figuerez M, Angulo I, Bourbon AI, Amado IR, Cerqueira MA, Pastrana LM, Hilliou LHG, Vicente AA, Cabedo L, and Lagaron JM
- Abstract
In the present study, a multilayer, high-barrier, thin blown film based on a polybutylene adipate terephthalate (PBAT) blend with polyhydroxyalkanoate (PHA), and composed of four layers including a cellulose nanocrystal (CNC) barrier layer and an electrospun poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) hot-tack layer, was characterized in terms of the surface roughness, surface tension, migration, mechanical and peel performance, barrier properties, and disintegration rate. The results showed that the film exhibited a smooth surface. The overall migration tests showed that the material is suitable to be used as a food contact layer. The addition of the CNC interlayer had a significant effect on the mechanical properties of the system, drastically reducing the elongation at break and, thus, the flexibility of the material. The film containing CNCs and electrospun PHBV hot-tack interlayers exhibited firm but not strong adhesion. However, the multilayer was a good barrier to water vapor (2.4 ± 0.1 × 10
-12 kg·m-2 ·s-1 ·Pa-1 ), and especially to oxygen (0.5 ± 0.3 × 10-15 m3 ·m-2 ·s-1 ·Pa-1 ), the permeance of which was reduced by up to 90% when the CNC layer was added. The multilayer system disintegrated completely in 60 days. All in all, the multilayer system developed resulted in a fully compostable structure with significant potential for use in high-barrier food packaging applications.- Published
- 2024
- Full Text
- View/download PDF
13. Designing an antimicrobial film for wound applications incorporating bacteriophages and ε-poly-l-lysine.
- Author
-
Pinto AM, Pereira R, Martins AJ, Pastrana LM, Cerqueira MA, and Sillankorva S
- Subjects
- Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Alginates chemistry, Bandages, Steam, Permeability, Anti-Infective Agents chemistry, Anti-Infective Agents pharmacology, Polylysine chemistry, Pseudomonas aeruginosa virology, Pseudomonas aeruginosa drug effects, Bacteriophages, Wound Healing
- Abstract
Alginate-based dressings have been shown to promote wound healing, leveraging the unique properties of alginate. This work aimed to develop and characterize flexible individual and bilayered films to deliver bacteriophages (phages) and ε-Poly-l-lysine (ε-PLL). Films varied in different properties. The moisture content, swelling and solubility increased with higher alginate concentrations. The water vapour permeability, crucial in biomedical films to balance moisture levels for effective wound healing, reached optimal levels in bilayer films, indicating these will be able to sustain an ideal moist environment. The bilayer films showed improved ductility (lower tensile strength and increased elongation at break) compared to individual films. The incorporated phages maintained viability for 12 weeks under vacuum and refrigerated conditions, and their release was sustained and gradual. Antibacterial immersion tests showed that films with phages and ε-PLL significantly inhibited Pseudomonas aeruginosa PAO1 growth (>3.1 Log CFU/cm
2 ). Particle release was influenced by the swelling degree and diffusional processes within the polymer network, providing insights into controlled release mechanisms for particles of varying size (50 nm to 6 μm) and charge. The films developed, demonstrated modulated release capabilities for active agents, and may show potential as controlled delivery systems for phages and wound healing adjuvants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2024
- Full Text
- View/download PDF
14. Active Low-Density Polyethylene-Based Films by Incorporating α-Tocopherol in the Free State and Loaded in PLA Nanoparticles: A Comparative Study.
- Author
-
Azevedo AG, Barros C, Miranda S, Machado AV, Carneiro OS, Silva B, Andrade MA, Vilarinho F, Saraiva M, Sanches Silva A, Pastrana LM, and Cerqueira MA
- Abstract
In this work, alpha-tocopherol (α-TOC) was encapsulated in poly(lactic acid) nanoparticles (PLA NPs) and added to low-density polyethylene (LDPE) films with the aim of producing an active film for food packaging applications. PLA NPs loaded with α-TOC were produced through nanoprecipitation and dried using two methods (freeze-dryer and oven). LDPE-based films with final polymeric matrix concentrations of 10 and 20 g/kg were then produced through blow extrusion. The results showed that LDPE-based films loaded with α-TOC can be produced using blow extrusion, and a good distribution of PLA NPs can be obtained within the LDPE matrix as observed using scanning electron microscopy (SEM). The mechanical properties were affected by the incorporation of α-TOC and PLA NPs loaded with α-TOC, with the observation of a decrease in tensile strength and Young's Modulus values and an increase in elongation at break. Regarding water vapor permeability, the films showed a reduction in the values with the addition of α-TOC and PLA NPs loaded with α-TOC compared to the LDPE film (control). Films with α-TOC in the free state and loaded in PLA NPs showed antioxidant activity, but their behavior was affected by the encapsulation process.
- Published
- 2024
- Full Text
- View/download PDF
15. Resveratrol-loaded octenyl succinic anhydride modified starch emulsions and hydroxypropyl methylcellulose (HPMC) microparticles: Cytotoxicity and antioxidant bioactivity assessment after in vitro digestion.
- Author
-
Silva PM, Neto MD, Cerqueira MA, Rodriguez I, Bourbon AI, Azevedo AG, Pastrana LM, Coimbra MA, Vicente AA, and Gonçalves C
- Subjects
- Humans, Emulsions chemistry, Resveratrol, Hypromellose Derivatives, Caco-2 Cells, Starch chemistry, Digestion, Antioxidants pharmacology, Succinic Anhydrides chemistry
- Abstract
Hydroxypropyl methylcellulose (HPMC)-based microparticles and modified starch emulsions (OSA-MS) were loaded with resveratrol and characterized regarding their physicochemical and thermal properties. Both delivery systems were subject to an in vitro gastrointestinal digestion to assess the bioaccessibility of resveratrol. In addition, cell-based studies were conducted after in vitro digestion and cytotoxicity and oxidative stress were assessed. HPMC-based microparticles displayed higher average sizes (d) and lower polydispersity index (PDI) (d = 948 nm, PDI < 0.2) when compared to OSA-MS-based emulsions (d = 217 nm, PDI < 0.3). Both proved to protect resveratrol under digestive conditions, leading to an increase in bioaccessibility. Resveratrol-loaded HPMC-microparticles showed a higher bioaccessibility (56.7 %) than resveratrol-loaded emulsions (19.7 %). Digested samples were tested in differentiated co-cultures of Caco-2 and HT29-MTX, aiming at assessing cytotoxicity and oxidative stress, and a lack of cytotoxicity was observed for all samples. Results displayed an increasing antioxidant activity, with 1.6-fold and 1.4-fold increases over the antioxidant activity of free resveratrol, for HPMC-microparticles and OSA-MS nanoemulsions, respectively. Our results offer insight into physiological relevancy due to assessment post-digestion and highlight the protection that the use of micro-nano delivery systems can confer to resveratrol and their potential to be used as functional food ingredients capable of providing antioxidant benefits upon consumption., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
16. Rhamnolipids: A biosurfactant for the development of lipid-based nanosystems for food applications.
- Author
-
Azevedo MA, Teixeira JA, Pastrana L, and Cerqueira MA
- Subjects
- Food, Surface-Active Agents chemistry, Glycolipids chemistry, Nanostructures
- Abstract
Biosurfactants (surfactants synthesized by microorganisms) are produced by microorganisms and are suitable for use in different areas. Among biosurfactants, rhamnolipids are the most studied and popular, attracting scientists, and industries' interest. Due to their unique characteristics, the rhamnolipids have been used as synthetic surfactants' alternatives and explored in food applications. Besides the production challenges that need to be tackled to guarantee efficient production and low cost, their properties need to be adjusted to the final application, where the pH instability needs to be considered. Moreover, regulatory approval is needed to start being used in commercial applications. One characteristic of interest is their capacity to form oil-in-water nanosystems. Some of the most explored have been nanoemulsions, solid-lipid nanoparticles and nanostructured lipid carriers. This review presents an overview of the main properties of rhamnolipids, asserts the potential and efficiency of rhamnolipids to replace the synthetic surfactants in the development of nanosystems, and describes the rhamnolipids-based nanosystems used in food applications. It also discusses the main characteristics and methodologies used for their characterization and in the end, some of the main challenges are highlighted., (© 2023 Institute of Food Technologists®.)
- Published
- 2024
- Full Text
- View/download PDF
17. Postharvest Quality Improvement of Tomato ( Solanum lycopersicum L.) Fruit Using a Nanomultilayer Coating Containing Aloe vera .
- Author
-
Flores-López ML, Vieira JM, Rocha CMR, Lagarón JM, Cerqueira MA, Jasso de Rodríguez D, and Vicente AA
- Abstract
The effectiveness of an alginate/chitosan nanomultilayer coating without (NM) and with Aloe vera liquid fraction (NM+Av) was evaluated on the postharvest quality of tomato fruit at 20 °C and 85% relative humidity (RH) to simulate direct consumption. Both nanomultilayer coatings had comparable effects on firmness and pH values. However, the NM+Av coating significantly reduced weight loss (4.5 ± 0.2%) and molds and yeasts (3.5-4.0 log CFU g
-1 ) compared to uncoated fruit (16.2 ± 1.2% and 8.0 ± 0.0 log CFU g-1 , respectively). It notably lowered O2 consumption by 70% and a 52% decrease in CO2 production, inhibiting ethylene synthesis. Visual evaluation confirmed NM+Av's efficacy in preserving the postharvest quality of tomato. The preservation of color, indicated by the Minolta color (a*/b*) values, demonstrated NM+Av's ability to keep the light red stage compared to uncoated fruit. The favorable effects of NM+Av coating on enhancing postharvest quality indicates it as a potential alternative for large-scale tomato fruit preservation.- Published
- 2023
- Full Text
- View/download PDF
18. Encapsulation of vitamin D3 using rhamnolipids-based nanostructured lipid carriers.
- Author
-
Azevedo MA, Cerqueira MA, Gonçalves C, Amado IR, Teixeira JA, and Pastrana L
- Subjects
- Cholecalciferol, Drug Carriers, Surface-Active Agents, Particle Size, Lipids, Nanostructures
- Abstract
This work had as main objective to encapsulate vitamin D3 (VD3) into nanostructured lipid carriers (NLCs) using rhamnolipids as surfactant. Glycerol monostearate and medium chain triglycerides with 2.625 % of VD3 were used as lipid materials. The three formulations of NLCs with VD3 (NLCs + VD3) were composed by 99 % of aqueous phase, 1 % of lipid phase and 0.05 % of surfactant. The difference between them was the ratio of solid:liquid in lipid phase. The NLCs + VD3 sizes ranged between 92.1 and 108.1 nm. The most stable formulation maintaining their caracteristics for 60 days at 4 °C. The NLCs + VD3 cytotoxicity demonstrated that concentrations of 0.25 mg/mL or lower up had a good biocompatibility in vitro. During the in vitro digestion, formulations with lower sizes and higher content on solid lipid had higher lipolysis rate and consequently higher VD3 bioaccessibility. The rhamnolipids-based NLCs are a good option for the encapsulation of VD3., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
19. Recent advances in oral delivery systems of resveratrol: foreseeing their use in functional foods.
- Author
-
Silva PM, Gonçalves C, Pastrana LM, Coimbra MA, Vicente AA, and Cerqueira MA
- Subjects
- Resveratrol, Antioxidants, Lipids chemistry, Polymers, Functional Food, Nanostructures chemistry
- Abstract
Herein, we review the current state-of-the-art on the use of micro- and nano-delivery systems, a possible solution to some of the drawbacks associated with the incorporation of resveratrol in foods. Specifically, we present an overview of a wide range of micro-nanostructures, namely, lipidic and polymeric, used for the delivery of resveratrol. Also, the gastrointestinal fate of resveratrol-loaded micro-nanostructures, as a critical parameter for their use as functional food, is explored in terms of stability, bioaccessibility, and bioavailability. Different micro-nanostructures are of interest for the development of functional foods given that they can provide different advantages and properties to these foods and even be tailor-made to address specific issues ( e.g. , controlled or targeted release). Therefore, we discuss a wide range of micro-nanostructures, namely, lipidic and polymeric, used to deliver resveratrol and aimed at the development of functional foods. It has been reported that the use of some production methodologies can be of greater interest than others, for example, emulsification, solvent displacement and electrohydrodynamic processing (EHDP) enable a greater increase in bioaccessibility. Additionally, the use of coatings facilitates further improvements in bioaccessibility, which is likely due to the increased gastric stability of the coated micro-nanostructures. Other properties, such as mucoadhesion, can also help improve bioaccessibility due to the increase in gut retention time. Additionally, cytotoxicity ( e.g. , biocompatibility, antioxidant, and anti-inflammatory) and possible sensorial impact of resveratrol-loaded micro- and nano-systems in foods are highlighted.
- Published
- 2023
- Full Text
- View/download PDF
20. Characterization of Sodium Alginate-Based Films Blended with Olive Leaf and Laurel Leaf Extracts Obtained by Ultrasound-Assisted Technology.
- Author
-
Moura-Alves M, Souza VGL, Silva JA, Esteves A, Pastrana LM, Saraiva C, and Cerqueira MA
- Abstract
Due to environmental concerns, there is an increasing need to reduce the use of synthetic and non-renewable packaging materials to reduce waste and increase sustainability. This study aimed to characterise sodium alginate edible-based films (SA) incorporated with laurel leaf extract (LLE) and olive leaf extract (OLE) obtained by ultrasound-assisted extraction. Determination of total phenolic content, antioxidant, and antimicrobial activity was performed for the extracts and films. Also, thickness, tensile strength, elongation at break, modulus of elasticity, opacity and colour, moisture content, water vapour permeability (WVP), Fourier-transform infrared spectroscopy (FTIR) spectra, and surface morphology by scanning electron microscope (SEM) analyses were performed for the films. LLE yielded better results in terms of phenolic content (195 mg GAE/g), antioxidant (2.1 TE/g extract) and antimicrobial activity (MIC at 1% for Listeria monocytogenes and Staphylococcus aureus , and 1.8% for Enterococcus faecalis ). For the films, the simultaneous incorporation of LLE 1% ( w / v ) and OLE 1% ( w / v ) resulted in a significant reduction of approximately 2 log CFU/g against S. aureus . The addition of LLE and OLE extracts also proved to improve barrier properties (lower WVP for SA films with LLE 1% + OLE 1%, 3.49 × 10
-11 g m-1 s-1 Pa-1 ) and promoted changes in resistance and flexibility. The results demonstrated that active alginate-based films can be valuable for enhancing food preservation.- Published
- 2023
- Full Text
- View/download PDF
21. Evaluation of the Antimicrobial Activity of Chitosan Nanoparticles against Listeria monocytogenes .
- Author
-
Pereira S, Costa-Ribeiro A, Teixeira P, Rodríguez-Lorenzo L, Prado M, Cerqueira MA, and Garrido-Maestu A
- Abstract
Chitosan is obtained from the deacetylation of chitin, and it is known to possess antimicrobial activity. It has attracted attention as it may be used for treating infections caused by different types of microorganisms due to its broad spectrum. Its application in the form of micro- or nanoparticles (CM/CN) has expanded its usage, as in this form, it retains its activity, and remain stable in aqueous solutions. However, inconsistencies in the results reported by different authors have been identified. In this communication, the antimicrobial activity of CN produced from different starting materials was tested against Listeria monocytogenes . It was observed that, even though all the starting materials were reported to have a molecular weight (MW) below 200 kDa and degree of deacetylation (DD) > 75%, the size of the CNs were significantly different (263 nm vs. 607 nm). Furthermore, these differences in sizes exerted a direct effect on the antimicrobial properties of the particles, as when testing the ones with the smallest size, i.e., 263 nm, a lower Minimum Inhibitory Concentration (MIC) was achieved, i.e., 0.04 mg/mL. Even though the largest particles, i.e., 607 nm, in individual experiments were able to achieve an MIC of 0.03 mg/mL, the results with CN presented great variation among replicates and up to 0.2 mg/mL were needed in other replicates. The starting material has a critical impact on the properties of the CN, and it must be carefully characterized and selected for the intended application, and MW and DD solely do not fully account for these properties.
- Published
- 2023
- Full Text
- View/download PDF
22. Edible alginate-based films with anti-SARS-CoV-2 activity.
- Author
-
Cerqueira MA, Leite ACCO, Tomás AL, Reichel A, Silva PM, Santos NC, Michelin M, Fuciños P, and Pastrana LM
- Subjects
- Humans, Alginates, Food Packaging methods, SARS-CoV-2, Antioxidants, Plant Extracts pharmacology, Tea, Antiviral Agents pharmacology, Gallic Acid pharmacology, Edible Films, COVID-19
- Abstract
The viability of SARS-CoV-2 on food surfaces and its propagation through the food chain has been discussed by several stakeholders, as it may represent a serious public health problem, bringing new challenges to the food system. This work shows for the first time that edible films can be used against SARS-CoV-2. Sodium alginate-based films containing gallic acid, geraniol, and green tea extract were evaluated in terms of their antiviral activity against SARS-CoV-2. The results showed that all these films have strong in vitro antiviral activity against this virus. However, a higher concentration of the active compound (1.25%) is needed for the film containing gallic acid to achieve similar results to those obtained for lower concentrations of geraniol and green tea extract (0.313%). Furthermore, critical concentrations of the active compounds in the films were used to evaluate their stability during storage. Results showed that gallic acid-loaded films lose their activity from the second week of storage, while films with geraniol and green tea extract only show a drop in activity after four weeks. These results highlight the possibility of using edible films and coatings as antiviral materials on food surfaces or food contact materials, which may help to reduce the spreading of viruses through the food chain., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
23. Bacteriophage Delivery Systems for Food Applications: Opportunities and Perspectives.
- Author
-
Costa MJ, Pastrana LM, Teixeira JA, Sillankorva SM, and Cerqueira MA
- Subjects
- Humans, Food Contamination prevention & control, Food Safety methods, Bacteria, Bacteriophages, Foodborne Diseases prevention & control, Foodborne Diseases microbiology
- Abstract
Currently, one-third of all food produced worldwide is wasted or lost, and bacterial contamination is one of the main reasons. Moreover, foodborne diseases are a severe problem, causing more than 420,000 deaths and nearly 600 million illnesses yearly, demanding more attention to food safety. Thus, new solutions need to be explored to tackle these problems. A possible solution for bacterial contamination is using bacteriophages (phages), which are harmless to humans; these natural viruses can be used to prevent or reduce food contamination by foodborne pathogens. In this regard, several studies showed the effectiveness of phages against bacteria. However, when used in their free form, phages can lose infectivity, decreasing the application in foods. To overcome this problem, new delivery systems are being studied to incorporate phages and ensure prolonged activity and controlled release in food systems. This review focuses on the existent and new phage delivery systems applied in the food industry to promote food safety. Initially, an overview of phages, their main advantages, and challenges is presented, followed by the different delivery systems, focused in methodologies, and biomaterials that can be used. In the end, examples of phage applications in foods are disclosed and future perspectives are approached.
- Published
- 2023
- Full Text
- View/download PDF
24. Assessment of the Antibiofilm Performance of Chitosan-Based Surfaces in Marine Environments.
- Author
-
Lima M, Gomes LC, Teixeira-Santos R, Romeu MJ, Valcarcel J, Vázquez JA, Cerqueira MA, Pastrana L, Bourbon AI, de Jong ED, Sjollema J, and Mergulhão FJ
- Subjects
- Biofilms, Paint, Chitosan pharmacology, Biofouling prevention & control, Anti-Infective Agents
- Abstract
Marine biofouling is a natural process often associated with biofilm formation on submerged surfaces, creating a massive economic and ecological burden. Although several antifouling paints have been used to prevent biofouling, growing ecological concerns emphasize the need to develop new and environmentally friendly antifouling approaches such as bio-based coatings. Chitosan (CS) is a natural polymer that has been widely used due to its outstanding biological properties, including non-toxicity and antimicrobial activity. This work aims to produce and characterize poly (lactic acid) (PLA)-CS surfaces with CS of different molecular weight (Mw) at different concentrations for application in marine paints. Loligo opalescens pens, a waste from the fishery industry, were used as a CS source. The antimicrobial activity of the CS and CS-functionalized surfaces was assessed against Cobetia marina , a model proteobacterium for marine biofouling. Results demonstrate that CS targets the bacterial cell membrane, and PLA-CS surfaces were able to reduce the number of culturable cells up to 68% compared to control, with this activity dependent on CS Mw. The antifouling performance was corroborated by Optical Coherence Tomography since PLA-CS surfaces reduced the biofilm thickness by up to 36%, as well as the percentage and size of biofilm empty spaces. Overall, CS coatings showed to be a promising approach to reducing biofouling in marine environments mimicked in this work, contributing to the valorization of fishing waste and encouraging further research on this topic.
- Published
- 2022
- Full Text
- View/download PDF
25. Alginate Particles for Encapsulation of Phenolic Extract from Spirulina sp. LEB-18: Physicochemical Characterization and Assessment of In Vitro Gastrointestinal Behavior.
- Author
-
Machado AR, Silva PMP, Vicente AA, Souza-Soares LA, Pinheiro AC, and Cerqueira MA
- Abstract
Encapsulation can be used as a strategy to protect and control the release of bioactive extracts. In this work, an extract from Spirulina sp. LEB-18, rich in phenolic compounds, was encapsulated in biopolymeric particles (i.e., composed of alginate) and characterized concerning their thermal behavior using differential scanning calorimetry (DSC), size, morphology, swelling index (S), and encapsulation efficiency (EE%); the release profile of the phenolic compounds at different pHs and the particle behavior under in vitro gastrointestinal digestion were also evaluated. It was shown that it is possible to encapsulate the phenolic extract from Spirulina sp. LEB-18 in alginate particles with high encapsulation efficiency (88.97%). It was also observed that the particles are amorphous and that the encapsulated phenolic compounds were released at a pH 7.2 but not at pH 1.5, which means that the alginate particles are able to protect the phenolic compounds from the harsh stomach conditions but lose their integrity under intestinal pH conditions. Regarding bioaccessibility, it was observed that the encapsulated phenolic compounds showed higher bioaccessibility compared to phenolic compounds in free form. This work increases the knowledge about the behavior of alginate particles encapsulating phenolic compounds during in vitro gastrointestinal digestion. It also provides essential information for designing biopolymeric particle formulations encapsulating phenolic compounds for application in pharmaceutical and food products.
- Published
- 2022
- Full Text
- View/download PDF
26. Zn and Zn-Fe Nanostructures with Multifunctional Properties as Components for Food Packaging Materials.
- Author
-
Lamsaf H, Ballesteros LF, Cerqueira MA, Teixeira JA, Pastrana LM, Rebouta L, Carvalho S, and Calderon S
- Abstract
Metallic and bimetallic nanostructures have shown interesting chromatic and antibacterial properties, and they can be used in various applications. In this work, zinc (Zn) and iron (Fe) nanostructures were produced with different morphologies: (i) pure Zn; (ii) Zn-Fe nanoalloys; (iii) Zn-Fe nanolayers (Zn-Fe NLs); and (iv) Zn nanolayers combined with Fe nanoparticles (Zn NLs + Fe NPs). The aim was to produce components for food packaging materials with active and intelligent properties, including oxygen absorption capacity, chromatic properties, and antibacterial properties. Thus, the morphology, structure, and chemical composition of the samples were characterized and correlated with their oxidation, chromatic, and antibacterial properties. The results revealed a relevant reduction in the coating's opacity after oxidation varying from 100 to 10% depending on the morphology of the system. All coatings exhibited significant antibacterial activity against S. aureus , revealing a direct correlation with Zn content. The incorporation of Fe for all atomic arrangements showed a negative impact on the antibacterial effect against E. coli , decreasing to less than half the zone of inhibition for Zn-Fe NLs and Zn NLs + Fe NPs and suppressing the antibacterial effect for Zn-Fe alloy when compared with the pure Zn system.
- Published
- 2022
- Full Text
- View/download PDF
27. Active Flexible Films for Food Packaging: A Review.
- Author
-
Azevedo AG, Barros C, Miranda S, Machado AV, Castro O, Silva B, Saraiva M, Silva AS, Pastrana L, Carneiro OS, and Cerqueira MA
- Abstract
Active food packaging is a dynamic area where the scientific community and industry have been trying to find new strategies to produce innovative packaging that is economically viable and compatible with conventional production processes. The materials used to develop active packaging can be organized into scavenging and emitting materials, and based on organic and inorganic materials. However, the incorporation of these materials in polymer-based flexible packaging is not always straightforward. The challenges to be faced are mainly related to active agents' sensitivity to high temperatures or difficulties in dispersing them in the high viscosity polymer matrix. This review provides an overview of methodologies and processes used in the production of active packaging, particularly for the production of active flexible films at the industrial level. The direct incorporation of active agents in polymer films is presented, focusing on the processing conditions and their effect on the active agent, and final application of the packaging material. Moreover, the incorporation of active agents by coating technologies and supercritical impregnation are presented. Finally, the use of carriers to help the incorporation of active agents and several methodologies is discussed. This review aims to guide academic and industrial researchers in the development of active flexible packaging, namely in the selection of the materials, methodologies, and process conditions.
- Published
- 2022
- Full Text
- View/download PDF
28. Oleogels and Organogels: A Promising Tool for New Functionalities.
- Author
-
Cerqueira MA, Valoppi F, and Pal K
- Abstract
Growing awareness concerning human health and sustainability has been continually driving the need to change consumers' habits and develop new bio-based and environmentally friendly materials that could be used in new product formulations [...].
- Published
- 2022
- Full Text
- View/download PDF
29. Hydroxypropyl methylcellulose-based micro- and nanostructures for encapsulation of melanoidins: Effect of electrohydrodynamic processing variables on morphological and physicochemical properties.
- Author
-
Silva PM, Prieto C, Andrade CCP, Lagarón JM, Pastrana LM, Coimbra MA, Vicente AA, and Cerqueira MA
- Subjects
- Electric Conductivity, Hypromellose Derivatives, Nanostructures, Polymers chemistry
- Abstract
Electrohydrodynamic processing (EHDP) allows the use of a wide range of biopolymers and solvents, including food-grade biopolymers and green solvents, for the development of micro- and nanostructures. These structures present a high surface-area-to-volume ratio and different shapes and morphologies. The aim of this work was to design and produce hydroxypropyl methylcellulose (HPMC)-based micro- and nanostructures through EHD processing using green solvents, while exploring the influence of process and solution parameters, and incorporating a bioactive extracted from a food by-product. Low (LMW) and high (HMW) molecular weight HPMC have been used as polymers. The design-of-experiments methodology was used to determine the effects of process parameters (polymer concentration, flow rate, tip-to-collector distance, and voltage) of EHDP on the particle and fibre diameter, aspect ratio, diameter distribution, aspect ratio distribution, and percentage of fibre breakage. Additionally, melanoidins extracted from spent coffee grounds were encapsulated into the HPCM-based structures at a concentration of 2.5 mg melanoidins/mL of the polymer solution. Polymer solutions were characterised regarding their viscosity, surface tension and conductivity, and showed that the incorporation of melanoidins increased the viscosity and conductivity values of the polymer solutions. The developed structures were characterised regarding their thermal properties, crystallinity and morphology before and after melanoidin incorporation and it was observed that melanoidin incorporation did not significantly influence the characteristics of the produced micro- and nanostructures. Based on the results, it is possible to envision the use of the produced micro- and nanostructures in a wide range of applications, both in food and biomedical fields., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
30. Gelation Behavior and Stability of Multicomponent Sterol-Based Oleogels.
- Author
-
Martins AJ, Cerqueira F, Vicente AA, Cunha RL, Pastrana LM, and Cerqueira MA
- Abstract
Novel fat mimetic materials, such as oleogels, are advancing the personalization of healthier food products and can be developed from low molecular weight compounds such as γ-oryzanol and β-sitosterol. Following molecular assembly, the formation of a tubular system ensues, which seems to be influenced by elements such as the oleogelators' concentration and ratio, cooling rates, and storage periods. Sterol-based oleogels were formulated under distinct environmental conditions, and a comprehensive study aimed to assess the effects of the mentioned factors on oleogel formation and stability, through visual observation and by using techniques such as small-angle X-ray scattering, X-ray diffraction, confocal Raman spectroscopy, rheology, and polarized microscopy. The long, rod-like conformations, identified by small-angle X-ray scattering, showed that different cooling rates influence oleogels' texture. Raman spectra showed that the stabilization time is associated with the interfibrillar aggregation, which occurred differently for 8 and 10 wt%, with a proven relationship between ferulic acid and the tubular formation. This report gives fundamental insight into the critical point of gelation, referring to the time scale of the molecular stabilization. Our results verify that understanding the structuring mechanisms of oleogelation is decisive for the processing and manufacturing of novel foods which integrate oleogels in their structure.
- Published
- 2022
- Full Text
- View/download PDF
31. Performance of Gelatin Films Reinforced with Cloisite Na + and Black Pepper Essential Oil Loaded Nanoemulsion.
- Author
-
Saranti TFDS, Melo PTS, Cerqueira MA, Aouada FA, and de Moura MR
- Abstract
The concern about consuming eco-friendly products has motivated research in the development of new materials. Therefore, films based on natural polymers have been used to replace traditional polymers. This study consists of a production of films based on gelatin reinforced with black pepper essential oil-loaded nanoemulsions and Cloisite Na
+ . The films were characterized by water vapor permeability, mechanical and thermal properties, surface contact angle, X-ray diffraction and scanning electron microscopy. It was observed that the films containing the nanoemulsion have higher permeability values and an increase in their mechanical resistance. The addition of nanoclay contributed to an increase in the surface hydrophobicity of the film and an increase in the tensile strength, at break, by about 150%. The addition of essential oil nanoemulsions led to an increase in thermal stability. The presence of clay dispersion contributed to the formation of a surface that was slightly rougher and grainier. The addition of the black pepper essential oil nanoemulsion resulted in an increase in porosity of the gelatin matrix. Through X-ray diffraction analysis, it was possible to conclude that both the polymeric gelatin matrix and the essential oils nanoemulsion are intercalated with the clay dispersion.- Published
- 2021
- Full Text
- View/download PDF
32. Effect of Biodegradable Hydrophilic and Hydrophobic Emulsifiers on the Oleogels Containing Sunflower Wax and Sunflower Oil.
- Author
-
Bharti D, Kim D, Cerqueira MA, Mohanty B, Habibullah SK, Banerjee I, and Pal K
- Abstract
The use of an appropriate oleogelator in the structuring of vegetable oil is a crucial point of consideration. Sunflower wax (SFW) is used as an oleogelator and displays an excellent potential to bind vegetable oils. The current study aimed to look for the effects of hydrophobic (SPAN-80) and hydrophilic (TWEEN-80) emulsifiers on the oleogels prepared using SFW and sunflower oil (SO). The biodegradability and all formulations showed globular crystals on their surface that varied in size and number. Wax ester, being the most abundant component of SFW, was found to produce fibrous and needle-like entanglements capable of binding more than 99% of SO. The formulations containing 3 mg of liquid emulsifiers in 20 g of oleogels showed better mechanical properties such as spreadability and lower firmness than the other tested concentrations. Although the FTIR spectra of all the formulations were similar, which indicated not much variation in the molecular interactions, XRD diffractograms confirmed the presence of β' form of fat crystals. Further, the mentioned formulations also showed larger average crystallite sizes, which was supported by slow gelation kinetics. A characteristic melting point (T
m ~60 °C) of triglyceride was visualized through DSC thermograms. However, a higher melting point in the case of few formulations suggests the possibility of even a stable β polymorph. The formed oleogels indicated the significant contribution of diffusion for curcumin release. Altogether, the use of SFW and SO oleogels with modified properties using biodegradable emulsifiers can be beneficial in replacing saturated fats and fat-derived products.- Published
- 2021
- Full Text
- View/download PDF
33. Development of Chitosan-Based Surfaces to Prevent Single- and Dual-Species Biofilms of Staphylococcus aureus and Pseudomonas aeruginosa .
- Author
-
Lima M, Teixeira-Santos R, Gomes LC, Faria SI, Valcarcel J, Vázquez JA, Cerqueira MA, Pastrana L, Bourbon AI, and Mergulhão FJ
- Subjects
- Biofilms growth & development, Surface Properties, Biofilms drug effects, Chitosan chemistry, Chitosan pharmacology, Implants, Experimental microbiology, Pseudomonas aeruginosa physiology, Staphylococcus aureus physiology
- Abstract
Implantable medical devices (IMDs) are susceptible to microbial adhesion and biofilm formation, which lead to several clinical complications, including the occurrence of implant-associated infections. Polylactic acid (PLA) and its composites are currently used for the construction of IMDs. In addition, chitosan (CS) is a natural polymer that has been widely used in the medical field due to its antimicrobial and antibiofilm properties, which can be dependent on molecular weight (Mw). The present study aims to evaluate the performance of CS-based surfaces of different Mw to inhibit bacterial biofilm formation. For this purpose, CS-based surfaces were produced by dip-coating and the presence of CS and its derivatives onto PLA films, as well surface homogeneity were confirmed by contact angle measurements, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The antimicrobial activity of the functionalized surfaces was evaluated against single- and dual-species biofilms of Staphylococcus aureus and Pseudomonas aeruginosa . Chitosan-based surfaces were able to inhibit the development of single- and dual-species biofilms by reducing the number of total, viable, culturable, and viable but nonculturable cells up to 79%, 90%, 81%, and 96%, respectively, being their activity dependent on chitosan Mw. The effect of CS-based surfaces on the inhibition of biofilm formation was corroborated by biofilm structure analysis using confocal laser scanning microscopy (CLSM), which revealed a decrease in the biovolume and thickness of the biofilm formed on CS-based surfaces compared to PLA. Overall, these results support the potential of low Mw CS for coating polymeric devices such as IMDs where the two bacteria tested are common colonizers and reduce their biofilm formation.
- Published
- 2021
- Full Text
- View/download PDF
34. Oleogel-Based Systems for the Delivery of Bioactive Compounds in Foods.
- Author
-
Pinto TC, Martins AJ, Pastrana L, Pereira MC, and Cerqueira MA
- Abstract
Oleogels are semi-solid materials containing a large fraction of liquid oil entrapped in a network of structuring molecules. In the food industry, these formulations can be used to mimic fats and to deliver bioactive compounds. In the last decade, there has been increasing interest in these structures, not only from a scientific point of view, i.e., studying new molecules, methodologies for gelification, and new structures, but also from a technological point of view, with researchers and companies exploring these structures as a way to overcome certain challenges and/or create new and innovative products. One of the exciting applications of oleogels is the delivery of functional molecules, where the incorporation of oil-soluble functional compounds can be explored not only at the macroscale but also at micro- and nanoscales, resulting in different release behaviors and also different applications. This review presents and discusses the most recent works on the development, production, characterization, and applications of oleogels and other oleogel-based systems to deliver functional molecules in foods.
- Published
- 2021
- Full Text
- View/download PDF
35. The Effect of Molecular Weight on the Antimicrobial Activity of Chitosan from Loligo opalescens for Food Packaging Applications.
- Author
-
Gomes LC, Faria SI, Valcarcel J, Vázquez JA, Cerqueira MA, Pastrana L, Bourbon AI, and Mergulhão FJ
- Subjects
- Animals, Aquatic Organisms, Biofilms drug effects, Escherichia coli drug effects, Food Packaging, Molecular Weight, Spectroscopy, Fourier Transform Infrared, Anti-Bacterial Agents pharmacology, Chitosan chemistry, Loligo
- Abstract
The growing requirement for sustainable processes has boosted the development of biodegradable plastic-based materials incorporating bioactive compounds obtained from waste, adding value to these products. Chitosan (Ch) is a biopolymer that can be obtained by deacetylation of chitin (found abundantly in waste from the fishery industry) and has valuable properties such as biocompatibility, biodegradability, antimicrobial activity, and easy film-forming ability. This study aimed to produce and characterize poly(lactic acid) (PLA) surfaces coated with β-chitosan and β-chitooligosaccharides from a Loligo opalescens pen with different molecular weights for application in the food industry. The PLA films with native and depolymerized Ch were functionalized through plasma oxygen treatment followed by dip-coating, and their physicochemical properties were assessed by Fourier-transform infrared spectroscopy, X-ray diffraction, water contact angle, and scanning electron microscopy. Their antimicrobial properties were assessed against Escherichia coli and Pseudomonas putida , where Ch-based surfaces reduced the number of biofilm viable, viable but nonculturable, and culturable cells by up to 73%, 74%, and 87%, respectively, compared to PLA. Biofilm growth inhibition was confirmed by confocal laser scanning microscopy. Results suggest that Ch films of higher molecular weight had higher antibiofilm activity under the food storage conditions mimicked in this work, contributing simultaneously to the reuse of marine waste.
- Published
- 2021
- Full Text
- View/download PDF
36. Active Carboxymethylcellulose-Based Edible Films: Influence of Free and Encapsulated Curcumin on Films' Properties.
- Author
-
Bourbon AI, Costa MJ, Maciel LC, Pastrana L, Vicente AA, and Cerqueira MA
- Abstract
Carboxymethylcellulose (CMC)-based films can act as a protective barrier in food surfaces and a carrier of bioactive compounds, such as curcumin. However, incorporating curcumin in hydrophilic matrixes can be a challenge, and new strategies need to be explored. In this work, CMC-based films containing free curcumin and curcumin-loaded nanohydrogels (composed of lactoferrin and glycomacropeptide) were produced and characterized. The incorporation of curcumin-loaded nanohydrogels showed a significant decrease in films' thickness (from 0.0791 to 0.029 mm). Furthermore, the water vapor permeability of CMC-based films was significantly decreased (62%) by incorporating curcumin-loaded nanohydrogels in the films. The water affinity's properties (moisture, solubility, and contact angle) of films were also affected by incorporating encapsulated curcumin. The addition of nanohydrogels to CMC-based films reduced the tensile strength values from 16.46 to 9.87 MPa. Chemical interactions were analyzed using Fourier transform infrared spectroscopy. The release profile of curcumin from CMC-based films was evaluated at 25 °C using a hydrophilic food simulant and suggests that the release mechanism of the curcumin happens by Fick's diffusion and Case II transport. Results showed that protein-based nanohydrogels can be a good strategy for incorporating curcumin in edible films, highlighting their potential for use in food applications., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
- Published
- 2021
- Full Text
- View/download PDF
37. Rhamnolipids-based nanostructured lipid carriers: Effect of lipid phase on physicochemical properties and stability.
- Author
-
Azevedo MA, Cerqueira MA, Fuciños P, Silva BFB, Teixeira JA, and Pastrana L
- Subjects
- Particle Size, Surface-Active Agents chemistry, Chemical Phenomena, Drug Carriers chemistry, Glycolipids chemistry, Nanostructures chemistry
- Abstract
In this work rhamnolipids were evaluated as surfactants for the production of nanostructured lipid carriers (NLCs). NLCs were produced by melt-emulsification using ultra-homogenisation followed by ultrasonication and different ratios of medium-chain-triglycerides and glycerol monostearate (lipid phase) were tested. NLCs presented sizes and polydispersity index values ranged between 97 and 120 nm and 0.20-0.26, respectively. Transmission electron microscopy observations confirmed the size and the spherical morphology of the NLCs. The thermal analysis and X-ray diffraction showed that the amount of solid lipid (glycerol monostearate) influences the melting, crystallisation and enthalpy of NLCs and their degree of crystallinity. Results showed that NLCs were more stable at 4 °C and the best formulation (1% of water phase, 0.05% of biosurfactant and solid:liquid ratio of 10:90) was stable for 30 days. This work showed the possibility of using rhamnolipids to produce NLCs and represent an important step for the development of lipid-based nanosystems using biosurfactants., (Copyright © 2020. Published by Elsevier Ltd.)
- Published
- 2021
- Full Text
- View/download PDF
38. Polysaccharide-Based Multilayer Nano-Emulsions Loaded with Oregano Oil: Production, Characterization, and In Vitro Digestion Assessment.
- Author
-
Espinosa-Sandoval L, Ochoa-Martínez C, Ayala-Aponte A, Pastrana L, Gonçalves C, and Cerqueira MA
- Abstract
The food industry has increased its interest in using "consumer-friendly" and natural ingredients to produce food products. In the case of emulsifiers, one of the possibilities is to use biopolymers with emulsification capacity, such as octenyl succinic anhydride modified starch, which can be used in combination with other polysaccharides, such as chitosan and carboxymethylcellulose, in order to improve the capacity to protect bioactive compounds. In this work, multilayer nano-emulsion systems loaded with oregano essential oil were produced by high energy methods and characterized. The process optimization was carried out based on the evaluation of particle size, polydispersity index, and zeta potential. Optimal conditions were achieved for one-layer nano-emulsions resulting in particle size and zeta potential of 180 nm and -42 mV, two layers (after chitosan addition) at 226 nm and 35 mV, and three layers (after carboxymethylcellulose addition) of 265 nm and -1 mV, respectively. The encapsulation efficiency of oregano essential oil within nano-emulsions was 97.1%. Stability was evaluated up to 21 days at 4 and 20 °C. The three layers nano-emulsion demonstrated to be an efficient delivery system of oregano essential oil, making 40% of the initial oregano essential oil available versus 13% obtained for oregano essential oil in oil, after exposure to simulated digestive conditions.
- Published
- 2021
- Full Text
- View/download PDF
39. Development of Active Barrier Multilayer Films Based on Electrospun Antimicrobial Hot-Tack Food Waste Derived Poly(3-hydroxybutyrate- co -3-hydroxyvalerate) and Cellulose Nanocrystal Interlayers.
- Author
-
Figueroa-Lopez KJ, Torres-Giner S, Angulo I, Pardo-Figuerez M, Escuin JM, Bourbon AI, Cabedo L, Nevo Y, Cerqueira MA, and Lagaron JM
- Abstract
Active multilayer films based on polyhydroxyalkanoates (PHAs) with and without high barrier coatings of cellulose nanocrystals (CNCs) were herein successfully developed. To this end, an electrospun antimicrobial hot-tack layer made of poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (PHBV) derived from cheese whey, a by-product from the dairy industry, was deposited on a previously manufactured blown film of commercial food contact PHA-based resin. A hybrid combination of oregano essential oil (OEO) and zinc oxide nanoparticles (ZnONPs) were incorporated during the electrospinning process into the PHBV nanofibers at 2.5 and 2.25 wt%, respectively, in order to provide antimicrobial properties. A barrier CNC coating was also applied by casting from an aqueous solution of nanocellulose at 2 wt% using a rod at 1m/min. The whole multilayer structure was thereafter assembled in a pilot roll-to-roll laminating system, where the blown PHA-based film was located as the outer layers while the electrospun antimicrobial hot-tack PHBV layer and the barrier CNC coating were placed as interlayers. The resultant multilayer films, having a final thickness in the 130-150 µm range, were characterized to ascertain their potential in biodegradable food packaging. The multilayers showed contact transparency, interlayer adhesion, improved barrier to water and limonene vapors, and intermediate mechanical performance. Moreover, the films presented high antimicrobial and antioxidant activities in both open and closed systems for up to 15 days. Finally, the food safety of the multilayers was assessed by migration and cytotoxicity tests, demonstrating that the films are safe to use in both alcoholic and acid food simulants and they are also not cytotoxic for Caco-2 cells.
- Published
- 2020
- Full Text
- View/download PDF
40. Graphene Oxide Increases Corneal Permeation of Ciprofloxacin Hydrochloride from Oleogels: A Study with Cocoa Butter-Based Oleogels.
- Author
-
Qureshi D, Choudhary B, Mohanty B, Sarkar P, Anis A, Cerqueira MA, Banerjee I, Maji S, and Pal K
- Abstract
In this work, oleogels of cocoa butter (CB), rice bran oil (RBO), and graphene oxide (GO) were prepared. The prepared oleogels were subjected to various characterization techniques such as bright-field microscopy, X-ray diffraction (XRD), crystallization kinetics, differential scanning calorimetry (DSC), and mechanical studies. The influence of increasing GO content on the in vitro drug release and ex vivo corneal permeation of the model drug (ciprofloxacin HCl-CPH) from the oleogels was also investigated. Bright-field micrographs showed that increment in GO content reduced the size of the globular particles of CB. XRD analysis revealed that CB was crystallized in its β' and β polymorphic forms in the oleogels, which was in agreement with thermal studies. The mechanical characterization demonstrated that the presence of GO improved the elastic nature and stress-bearing properties of the oleogels. Moreover, GO altered the crystallization kinetics of CB in the oleogels in a composition-dependent manner. The in vitro release of CPH from the oleogels occurred through either Fickian diffusion or fat network relaxation or a combination thereof. Furthermore, the inclusion of GO enhanced the ex vivo permeation of CPH molecules across the caprine cornea. Hence, we concluded that the prepared oleogels could be explored as potential delivery systems for ophthalmic applications.
- Published
- 2020
- Full Text
- View/download PDF
41. Green synthesis of lignin nano- and micro-particles: Physicochemical characterization, bioactive properties and cytotoxicity assessment.
- Author
-
Freitas FMC, Cerqueira MA, Gonçalves C, Azinheiro S, Garrido-Maestu A, Vicente AA, Pastrana LM, Teixeira JA, and Michelin M
- Subjects
- Anti-Bacterial Agents chemical synthesis, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, Antineoplastic Agents chemical synthesis, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, Antioxidants chemical synthesis, Antioxidants chemistry, Antioxidants pharmacology, Caco-2 Cells, Cell Proliferation drug effects, Escherichia coli drug effects, Escherichia coli pathogenicity, Ethanol chemistry, Humans, Lignin chemical synthesis, Lignin pharmacology, Microplastics chemistry, Microplastics pharmacology, Salmonella enterica drug effects, Salmonella enterica pathogenicity, Water chemistry, Green Chemistry Technology, Lignin chemistry, Microplastics chemical synthesis, Nanoparticles chemistry
- Abstract
Lignin particles (LPs) have gained prominence due to their biodegradability and bioactive properties. LP production at nano and micro scale produced from organosolv lignin and the understanding of size's effect on their properties is unexplored. This work aimed to produce and characterize lignin nanoparticles and microparticles using a green synthesis process, based on ethanol-solubilized lignin and water. Spherical shape LPs, with a mean size of 75 nm and 215 nm and with a low polydispersity were produced, as confirmed by transmission electron microscopy and dynamic light scattering. LPs thermal stability improved over raw lignin, and the chemical structure of lignin was not affected by the production method. The antimicrobial tests proved that LPs presented a bacteriostatic effect on Escherichiacoli and Salmonella enterica. Regarding the antioxidant potential, LPs had a good antioxidant activity that increased with the reaction time and LPs concentration. LPs also presented an antioxidant effect against intracellular ROS, reducing the intracellular ROS levels significantly. Furthermore, the LPs showed a low cytotoxic effect in Caco-2 cell line. These results showed that LPs at different scales (nano and micro) present biological properties and are safe to be used in different high value industrial sectors, such as biomedical, pharmaceutical and food., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
42. Self-assembled lipids for food applications: A review.
- Author
-
Magri A, Petriccione M, Cerqueira MA, and Gutiérrez TJ
- Subjects
- Drug Carriers chemistry, Functional Food analysis, Nanotechnology, Food, Lipids chemistry
- Abstract
Lipids play an important role in human nutrition. Several foodstuffs can be manufactured from the simple, compound and derived lipids. In particular, the use of self-assembled lipids (SLs, e.g. self-assembled L-α-lecithin) has brought great attention for the development of tailored, tuned and targeted colloidal structures loading degradation-sensitive substances with valuable antimicrobial, antioxidant and nutraceutical properties for food applications. For example, polyunsaturated fatty acids (PUFAs) and essential oils can be protected from degradation, thus improving their bioavailability in general terms in consumers. From a nanotechnological point of view, SLs allow the development of advanced and multifaceted architectures, in which each molecule of them are used as building blocks to obtain designed and ordered structures. It is important to note before beginning this review, that simple and compound lipids are the main SLs, while essential fatty acids and derived lipids in general have been considered by many research groups as the bulk loaded substances within several structures from self-assembled carbohydrates, proteins and lipids. However, this review paper is addressed on the analysis of the lipid-lipid self-assembly. Lipids can be self-assembled into various structures (micelles, vesicular systems, lyotropic liquid crystals, oleogels and films) to be used in different food applications: coatings, controlled and sustained release materials, emulsions, functional foods, etc. SLs can be obtained via non-covalent chemical interactions, primarily by hydrogen, hydrophilic and ionic bonding, which are influenced by the conditions of ionic strength, pH, temperature, among others. This manuscript aims to give an analysis of the specific state-of-the-art of SLs for food applications, based primarily on the literature reported in the past five years., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
43. Bio-Based Nanoparticles as a Carrier of β-Carotene: Production, Characterisation and In Vitro Gastrointestinal Digestion.
- Author
-
Afonso BS, Azevedo AG, Gonçalves C, Amado IR, Ferreira EC, Pastrana LM, and Cerqueira MA
- Subjects
- Nanoparticles ultrastructure, Particle Size, Spectroscopy, Fourier Transform Infrared, Static Electricity, X-Ray Diffraction, Zein chemistry, Digestion physiology, Drug Carriers chemistry, Gastrointestinal Tract physiology, Nanoparticles chemistry, beta Carotene chemistry
- Abstract
β-carotene loaded bio-based nanoparticles (NPs) were produced by the solvent-displacement method using two polymers: zein and ethylcellulose. The production of NPs was optimised through an experimental design and characterised in terms of average size and polydispersity index. The processing conditions that allowed to obtain NPs (<100 nm) were used for β-carotene encapsulation. Then β-carotene loaded NPs were characterised in terms of zeta potential and encapsulation efficiency. Transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction analysis were performed for further morphological and chemical characterisation. In the end, a static in vitro digestion following the INFOGEST protocol was performed and the bioaccessibility of β-carotene encapsulated in both NPs was determined. Results show that the best conditions for a size-controlled production with a narrow size distribution are lower polymer concentrations and higher antisolvent concentrations. The encapsulation of β-carotene in ethylcellulose NPs resulted in nanoparticles with a mean average size of 60 ± 9 nm and encapsulation efficiency of 74 ± 2%. β-carotene loaded zein-based NPs resulted in a mean size of 83 ± 8 nm and encapsulation efficiency of 93 ± 4%. Results obtained from the in vitro digestion showed that β-carotene bioaccessibility when encapsulated in zein NPs is 37 ± 1%, which is higher than the value of 8.3 ± 0.1% obtained for the ethylcellulose NPs.
- Published
- 2020
- Full Text
- View/download PDF
44. Development and Evaluation of Superabsorbent Hydrogels Based on Natural Polymers.
- Author
-
Batista RA, Espitia PJP, Vergne DMC, Vicente AA, Pereira PAC, Cerqueira MA, Teixeira JA, Jovanovic J, Severino P, Souto EB, and Cardoso JC
- Abstract
Superabsorbent hydrogels (SAHs) are three dimensional networks formed by polymers that can absorb aqueous solution of over 100% of their initial weight. This work aimed to develop and characterize SAHs of Chitosan/Xanthan gum (CG), Chitosan/Alginate (CA) and controlled Chitosan (C), Xanthan gum (G), and Alginate (A) produced using "onion-like" methodology. The swelling performance, the morphological structure, the crystallinity, and the Fourier transformed infrared spectroscopy characteristics of SAH were used for the characterization of polyelectrolytes complex. Swelling analysis showed that chitosan has a strong influence on the maintenance of hydrogels structure after swelling, mainly in the acid environment (pH = 2). The chitosan hydrogel presented around 3000% of acidic fluid absorption after 24 h. The chitosan:xanthan gum (1:1 and 2:1 named as C1G1 and C2G1, respectively) hydrogels were the best combination regarding swelling performance in an acid environment, reaching 1665% and 2024%, respectively, as well at pH 7.0, presenting 1005% (C1G1) and 667% (C2G1). Scanning electron microscopy analysis showed samples with pores, and with different shapes. The X-ray diffraction showed the presence of a characteristic peak at 2θ = 20° in all developed composition because of the crystalline nature of chitosan. This work shows the possibility of developing eco-friendly biopolymer-based SAHs at a low cost with a good swelling capacity and stability.
- Published
- 2020
- Full Text
- View/download PDF
45. Electrosprayed whey protein-based nanocapsules for β-carotene encapsulation.
- Author
-
Rodrigues RM, Ramos PE, Cerqueira MF, Teixeira JA, Vicente AA, Pastrana LM, Pereira RN, and Cerqueira MA
- Subjects
- Animals, Cattle, Electrons, Microscopy, Electrochemical, Scanning, Nanocapsules ultrastructure, Nanocapsules chemistry, Whey Proteins chemistry, beta Carotene chemistry
- Abstract
In this work an electrohydrodynamic process (electrospray) was used to produce β-carotene loaded nanocapsules based on whey protein isolate (WPI). WPI solutions were prepared in aqueous solutions with different concentrations of ethanol (5, 10 and 15%) which were used for β-carotene solubilization. Different electrospray conditions were tested and the morphology and molecular organization of the nanocapsules were studied on dried and hydrated state. The size of the dried nanocapsules ranged between 227 and 283 nm. After hydration, there was a significant increase in the mean size of the nanocapsules, being the sizes higher for nanocapsules produced with increasing concentrations of ethanol. Results, obtained from the reactivity of free sulfhydryl groups and fluorescence analysis, showed that the increase of ethanol concentration had a destabilizing effect on the protein unfolding. Electrosprayed WPI-based nanocapsules can be used for the encapsulation of β-carotene answering the industrial demand for novel encapsulation technologies to protect sensitive bioactive compounds., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
46. Characterization of Enriched Meat-Based Pâté Manufactured with Oleogels as Fat Substitutes.
- Author
-
Martins AJ, Lorenzo JM, Franco D, Pateiro M, Domínguez R, Munekata PES, Pastrana LM, Vicente AA, Cunha RL, and Cerqueira MA
- Abstract
Nowadays, one of the strongest factors affecting consumers' choice at the moment of purchasing food products is their nutritional features. The population is increasingly aware of the diet-health relationship and they are opting for a healthy lifestyle. Concerns with the increasing number of heart-related diseases, which are associated to the consumption of fats, are placing the functional food market in a relevant growth position. Considering that, our goal was to develop, under semi-industrial processing conditions, a healthy meat-based spreadable product (pâté) with reduced fat content through replacement of pork fat by healthier structured oil. Beeswax was used to develop an edible oleogel based on linseed oil with a high content of linolenic acid. A decrease of the hardness and adhesivity was verified for pâtés with oleogel incorporation. Linseed oil inclusion was the main factor leading to an increase of polyunsaturated fatty acids (PUFA) content in pâté samples. A decrease up to 90% in the n-6/n-3 (omega-6/omega-3) ratio can signify a better nutritional value of the obtained pâté samples, which can result in a possible upsurge in omega-3 bioavailability through digestion of these pâtés. This could be an interesting option for the consumption of n-3 polyunsaturated fatty acids, targeting, for example, the reduction of cardiovascular diseases.
- Published
- 2020
- Full Text
- View/download PDF
47. Electrospun Active Biopapers of Food Waste Derived Poly(3-hydroxybutyrate- co -3-hydroxyvalerate) with Short-Term and Long-Term Antimicrobial Performance.
- Author
-
Figueroa-Lopez KJ, Torres-Giner S, Enescu D, Cabedo L, Cerqueira MA, Pastrana LM, and Lagaron JM
- Abstract
This research reports about the development by electrospinning of fiber-based films made of poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (PHBV) derived from fermented fruit waste, so-called bio-papers, with enhanced antimicrobial performance. To this end, different combinations of oregano essential oil (OEO) and zinc oxide nanoparticles (ZnONPs) were added to PHBV solutions and electrospun into mats that were, thereafter, converted into homogeneous and continuous films of ~130 μm. The morphology, optical, thermal, mechanical properties, crystallinity, and migration into food simulants of the resultant PHBV-based bio-papers were evaluated and their antimicrobial properties were assessed against Staphylococcus aureus ( S. aureus ) and Escherichia coli ( E. coli ) in both open and closed systems. It was observed that the antimicrobial activity decreased after 15 days due to the release of the volatile compounds, whereas the bio-papers filled with ZnONPs showed high antimicrobial activity for up to 48 days. The electrospun PHBV biopapers containing 2.5 wt% OEO + 2.25 wt% ZnONPs successfully provided the most optimal activity for short and long periods against both bacteria.
- Published
- 2020
- Full Text
- View/download PDF
48. Lactoferrin-based nanoemulsions to improve the physical and chemical stability of omega-3 fatty acids.
- Author
-
Nunes R, Pereira BD, Cerqueira MA, Silva P, Pastrana LM, Vicente AA, Martins JT, and Bourbon AI
- Subjects
- Caco-2 Cells, Cell Survival, Emulsifying Agents chemistry, Emulsions, Humans, Oxidation-Reduction, Particle Size, Fatty Acids, Omega-3 chemistry, Food Technology, Lactoferrin chemistry, Nanostructures
- Abstract
Omega-3 (ω-3) polyunsaturated fatty acids are highly susceptible to oxidation and have an intense odour and poor water solubility, which make their direct applications in foods extremely difficult. In order to reduce their oxidation process and improve their stability in aqueous medium, protein-based nanoemulsions were produced and characterized. Lactoferrin (Lf) was used as an emulsifier at different concentrations (0.2% to 4% w/w). High energy methods (Ultra-Turrax and high-pressure homogenizer) were applied to produce Lf-based nanoemulsions with ω-3 PUFAs encapsulated. The nanoemulsions were characterized in terms of physical and chemical stability at 4 and 25 °C. The results obtained revealed that the Lf concentration influences the nanoemulsion size in a manner that higher Lf concentrations decrease the nanoemulsion size. It was also observed that the nanoemulsions are physically stable when stored at 4 °C for 69 days while at 25 °C they showed instability. The radical scavenging capacity of the nanoemulsions did not show significant changes over storage at 4 and 25 °C while a significant increase in oxidation was observed. The release profile at 37 °C showed that ω-3 PUFAs were slowly released at pH 2 but was rapidly released at pH 7.4 from Lf nanoemulsions. Moreover, MTT assay revealed that 2% (w/w) Lf nanoemulsions with 12.5 μg mL
-1 ω-3 PUFAs were not cytotoxic to Caco-2 cells. Nanoemulsions with high physical and chemical stability were selected and dried by two different methodologies: freeze-drying and nano spray-drying. ATR-FTIR spectroscopy, Raman spectroscopy and Circular Dichroism (CD) showed Lf structural changes after the drying processes. This work provides important information regarding nanoemulsions' design and drying technologies aiming at the encapsulation of lipophilic compounds for pharmaceutical and food applications.- Published
- 2020
- Full Text
- View/download PDF
49. T cells CD4+/CD8+ local immune modulation by prostate cancer hemi-cryoablation.
- Author
-
Cerqueira MA, Ferrari KL, de Mattos AC, Monti CR, and Reis LO
- Subjects
- Adenocarcinoma immunology, Adenocarcinoma pathology, CD4-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes immunology, Humans, Lymphocytes, Tumor-Infiltrating immunology, Male, Neoplasm Staging, Prospective Studies, Prostatic Neoplasms immunology, Prostatic Neoplasms pathology, Tumor Microenvironment immunology, Adenocarcinoma surgery, CD4-Positive T-Lymphocytes pathology, CD8-Positive T-Lymphocytes pathology, Cryosurgery methods, Lymphocytes, Tumor-Infiltrating pathology, Prostatic Neoplasms surgery
- Abstract
Purpose: Tumors escape from the immune system by decreasing CD8+ and increasing CD4+ T cells' activity, druggable targets. Thermal ablation might activate tumor-specific T cells by raising the presentation of tumor-specific antigens and hindering tumor negative immune regulation. Our aim was to assess T cell infiltrate pre- and post-cryoablation in a prospective observational study., Methods: A total of 240 sextant prostate biopsies cores (12 cores/patient) were collected from 10 unilateral prostate cancer patients (T1c, PSA density < 0.15 ng/dL, Gleason grade group 1, ≤ 2 cancer biopsy cores, and < 50% cancer core involvement) at diagnosis and 12 months after hemi-cryoablation. Cancer-positive (Diag+) and cancer-negative (Diag-) lobes at diagnosis and the same areas 12 months after hemi-cryoablation (Cryo+ and Cryo-, respectively) were explored by immunohistochemistry for infiltrating CD4+ and CD8+ T cells (in 45 random fields per prostate lobe, 400× magnification). The quantitative analysis of cells/mm
2 and CD4+/CD8+ ratio were performed and compared among Diag+, Diag-, Cryo+, and Cryo- using ImageJ software., Results: There was a significant increase in tumor-infiltrating CD8+ T cells/mm2 in the Cryo+ tissue (mean, SD 0.31, 0.30) compared to Diag+ (0.18, 0.15), p = 0.015; confirmed in prostate acini (hot spots), p = 0.029, in which infiltrating CD4+/CD8+ T cells' ratio decreased after hemi-cryoablation, p = 0.006. Infiltrating CD4+ T cells/mm2 presented a trend to decrease in Cryo+ (0.26, 0.27) compared to Diag+ (0.38, 0.32)., Conclusions: This is the first study to show local immune modulation after prostate cancer cryoablation, characterized by decreasing CD4+/CD8+ T cells' ratio, potential for clinical impact by unleashing the T-cell response to cancer. Future studies are necessary to explore different energies and longer follow-up clinical endpoints.- Published
- 2020
- Full Text
- View/download PDF
50. Mid-term post-fire losses of nitrogen and phosphorus by overland flow in two contrasting eucalypt stands in north-central Portugal.
- Author
-
Serpa D, Ferreira RV, Machado AI, Cerqueira MA, and Keizer JJ
- Subjects
- Ecosystem, Mediterranean Region, Portugal, Nitrogen analysis, Phosphorus analysis
- Abstract
Wildfires affect vast areas of Mediterranean forests, thereby triggering changes in hydrological and geomorphological processes that can negatively affect both terrestrial and aquatic ecosystems. Although several studies have evaluated the post-fire hydrological and erosive response in burnt forest areas, an important knowledge gap remains with respect to nutrient mobilization by overland flow. To address this gap, a recently burnt area was selected near the Ermida village (north-central Portugal). The study area was instrumented shortly after a wildfire that occurred in July 2010, to evaluate the export of dissolved (nitrate - NO
3 -N and orthophosphate - PO4 -P) and total nitrogen (TN) and phosphorus (TP) forms by overland flow. This was done in two burnt eucalyptus plantations due to their contrasting slope aspects (south-east vs. north-west). Bounded micro-plots were installed in August 2010 and monitored over two years. During this period, overland flow samples were collected on a 1- to 2-weekly basis, depending on the occurrence of rain. Results showed that the north west-facing slope (BE-N) presented higher nutrient losses than the south east-facing slope (BE-S), contradicting the findings of previous studies in the Mediterranean region. A logging operation that had taken place at the BE-N site shortly before the fire might account for these findings, by causing soil compaction and/or reducing the protective vegetation and litter cover. TN and TP exports were particularly pronounced during the first four months following the wildfire. After this initial period, further peaks in TN and TP exports occurred sporadically, mainly associated to intense rainfall events. The observed mid-term post-fire nutrient losses not only suggested a threat to the soil nutrient balance of Mediterranean eucalypt forests but also a potential risk of eutrophication of downstream water bodies., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2020
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.