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1.
Food Res Int ; 143: 110228, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33992342

RESUMEN

This study investigated the potential of isochoric freezing to preserve tomatoes. Isochoric freezing is an emerging technology that preserves biological matter at subfreezing temperatures without any ice damage. Isochoric freezing was compared with freezing under isobaric conditions and with preservation techniques used in the food industry: cold storage at 10 °C and individual quick freezing (IQF). Physicochemical and nutritional properties were evaluated weekly for four weeks. Preservation under isochoric conditions maintained the mass, color, nutrient content (ascorbic acid, lycopene and phenolics) and antioxidant activity of the fresh tomatoes. Also, isochoric preservation led to minimal texture damage. In comparison, mass loss of tomatoes stored at 10 °C for 3 weeks contributed to changes in overall visual quality and firmness as well as significant losses in nutrient content. The greatest mass, texture, and nutrients losses were obtained for tomatoes subjected to IQF and isobaric freezing. The results show that isochoric freezing has the potential to preserve tomatoes while maintaining physicochemical and nutritional properties similar to those of fresh tomatoes which might find application in the commercial preservation of tomatoes.


Asunto(s)
Lycopersicon esculentum , Vitis , Criopreservación , Congelación , Isocoras
2.
Foods ; 10(2)2021 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-33670567

RESUMEN

The cracking of sweet cherries causes significant crop losses. Sweet cherries (cv. Bing) were coated by electro-spraying with an edible nanoemulsion (NE) of alginate and soybean oil with or without a CaCl2 cross-linker to reduce cracking. Coated sweet cherries were stored at 4 °C for 28 d. The barrier and fruit quality properties and nutritional values of the coated cherries were evaluated and compared with those of uncoated sweet cherries. Sweet cherries coated with NE + CaCl2 increased cracking tolerance by 53% and increased firmness. However, coated sweet cherries exhibited a 10% increase in water loss after 28 d due to decreased resistance to water vapor transfer. Coated sweet cherries showed a higher soluble solid content, titratable acidity, antioxidant capacity, and total soluble phenolic content compared with uncoated sweet cherries. Therefore, the use of the NE + CaCl2 coating on sweet cherries can help reduce cracking and maintain their postharvest quality.

3.
Carbohydr Polym ; 252: 117165, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33183616

RESUMEN

Commercializing dried microfibrillated cellulose (MFC) has always been a challenge mainly due to the tendency of MFC to aggregate. In this study MFC samples were submitted to drying/redispersion cycles at different temperatures. Morphology, crystallinity and mechanical performance of films were analyzed throughout the cycles. Microscopy images, particle size and stability in water showed that aggregation happens more severely with 5 drying/redispersion cycles and at drying temperatures of 75 and 100 °C. Particles once-dried at 20 °C formed the same size and web-like structure as the MFC-control. Crystallinity and crystallite sizes increased with drying/redispersion cycles especially when dried at 75 and 100 °C, however drying/redispersion cycles also led to a reduction in mechanical performance due to aggregation. While oven-drying is not the most suitable method, milder action at room temperature once-drying led to suspension stability in water, morphology and mechanical properties close to never-dried MFC, which makes this treatment a feasible option to maintain cellulose quality.

4.
Theor Appl Genet ; 133(11): 3119-3137, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32803378

RESUMEN

KEY MESSAGE: Quantitation of leaf surface wax on a population of switchgrass identified three significant QTL present across six environments that contribute to leaf glaucousness and wax composition and that show complex genetic × environmental (G × E) interactions. The C4 perennial grass Panicum virgatum (switchgrass) is a native species of the North American tallgrass prairie. This adaptable plant can be grown on marginal lands and is useful for soil and water conservation, biomass production, and as a forage. Two major switchgrass ecotypes, lowland and upland, differ in a range of desirable traits, and the responsible underlying loci can be localized efficiently in a pseudotestcross design. An outbred four-way cross (4WCR) mapping population of 750 F2 lines was used to examine the genetic basis of differences in leaf surface wax load between two lowland (AP13 and WBC) and two upland (DAC and VS16) tetraploid cultivars. The objective of our experiments was to identify wax compositional variation among the population founders and to map underlying loci responsible for surface wax variation across environments. GCMS analyses of surface wax extracted from 4WCR F0 founders and F1 hybrids reveal higher levels of wax in lowland genotypes and show quantitative differences of ß-diketones, primary alcohols, and other wax constituents. The full mapping population was sampled over two seasons from four field sites with latitudes ranging from 30 to 42 °N, and leaf surface wax was measured. We identified three high-confidence QTL, of which two displayed significant G × E effects. Over 50 candidate genes underlying the QTL regions showed similarity to genes in either Arabidopsis or barley known to function in wax synthesis, modification, regulation, and transport.


Asunto(s)
Interacción Gen-Ambiente , Panicum/genética , Hojas de la Planta/química , Sitios de Carácter Cuantitativo , Ceras , Mapeo Cromosómico , Cruzamientos Genéticos , Ecotipo , Ligamiento Genético , Genotipo , Panicum/química , Fenotipo , Tetraploidía
5.
J Food Sci ; 85(9): 2656-2664, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32860220

RESUMEN

The enhanced interest in greater convenience foods has recently led to the expansion of minimally processed potato products. This study investigated the effects of isochoric freezing on pre-peeled potato cubes, including quality attributes (microstructure, texture, and color), nutritional value (ascorbic acid (AA) content, total phenolic content, and antioxidant capacity), and polyphenol oxidase activity. Isochoric freezing (-3 °C/30 MPa) was compared with isobaric freezing (-3 °C/0.1 MPa) and individual quick freezing followed by frozen storage at -20 °C for 4 weeks. The isochoric sample had lower drip loss and volume shrinkage as well as better preserved texture and microstructure than the other samples. All freezing methods caused an increase in total phenolic content and antioxidant capacity, but a decrease in AA content. Also, all freezing methods caused browning of the thawed potatoes, but isochoric freezing delayed its onset for more than 1 week. PRACTICAL APPLICATION: Results showed that isochoric freezing of pre-peeled and cut potatoes caused less freeze damage than isobaric and individual quick freezing, which might find application in the commercial preservation of minimally processed food products.


Asunto(s)
Conservación de Alimentos/métodos , Tubérculos de la Planta/química , Solanum tuberosum/química , Antioxidantes/análisis , Ácido Ascórbico/análisis , Congelación , Valor Nutritivo , Oxidación-Reducción , Fenoles/análisis
6.
Med Humanit ; 45(3): 294-303, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31371484

RESUMEN

Health research is often bounded by disciplinary expertise. While cross-disciplinary collaborations are often forged, the analysis of data which draws on more than one discipline at the same time is underexplored. Life of Breath, a 5-year project funded by the Wellcome Trust to understand the clinical, historical and cultural phenomenology of the breath and breathlessness, brings together an interdisciplinary team, including medical humanities scholars, respiratory clinicians, medical anthropologists, medical historians, cultural theorists, artists and philosophers. While individual members of the Life of Breath team come together to share ongoing work, collaborate and learn from each other's approach, we also had the ambition to explore the feasibility of integrating our approaches in a shared response to the same piece of textual data. In this article, we present our pluralistic, interdisciplinary analysis of an excerpt from a single cognitive interview transcript with a patient with chronic obstructive pulmonary disease. We discuss the variation in the responses and interpretations of the data, why research into breathlessness may particularly benefit from an interdisciplinary approach, and the wider implications of the findings for interdisciplinary research within health and medicine.


Asunto(s)
Investigación Biomédica/métodos , Disnea , Relaciones Interprofesionales , Conducta Cooperativa , Interpretación Estadística de Datos , Humanos , Comunicación Interdisciplinaria
7.
Polymers (Basel) ; 11(8)2019 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-31370362

RESUMEN

This paper provides proof of concept that activated carbon (AC) may be readily produced using limited conversion methods and resources from sawdust of massaranduba (Manilkara huberi) wood, thereby obtaining value-added products. Sawdust was sieved and heat-treated in an oxygen-free muffle furnace at 500 °C to produce charcoal. The charcoal was activated in a tubular electric furnace at 850 °C while being purged with CO2 gas. Microstructural, thermal and physical properties of the three components: sawdust, charcoal and AC were compared by means of field emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), density and water adsorption/desorption measurements. The resulting AC had a large surface area as measured by Brunauer-Emmett-Teller (BET) comparable to other such values found in the literature. The large surface area was due to pore development at the microstructural level as shown by FESEM. XRD illustrated that sawdust had a semi-crystalline structure whereas charcoal and AC evidenced mostly amorphous structures. TGA and DSC showed that AC had high reactivity to moisture compared to sawdust and charcoal.

8.
Carbohydr Polym ; 207: 100-107, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30599989

RESUMEN

The objective of this work was to prepare bio-based thin films and evaluate the additions of magnetite and glycerol on the physico-chemical (flexibility, wettability and barrier properties) and dielectric properties of cellulose/chitosan-based films. The films were prepared by solution casting and presented a suitable dispersion of the constituents observed by SEM and FTIR. The films were thermally stable up to 150 °C and had a higher flexibility, wettability and lower barrier properties upon addition of glycerol. The calculated dielectric constant (εr) for the composite films was based on measurements of capacitance, at 100 and 1000 Hz, with the additions of magnetite and glycerol more than doubling the εr increasing the charge storage capacity. The bio-based thin films have potential to be used as insulators in capacitors on the production of green electronics thus, reducing toxic and nonrenewable e-waste generation.


Asunto(s)
Celulosa/química , Óxido Ferrosoférrico/química , Nanofibras/química , Quitosano/química , Módulo de Elasticidad , Capacidad Eléctrica , Glicerol/química , Tecnología Química Verde/instrumentación , Fenómenos Magnéticos , Resistencia a la Tracción , Humectabilidad
9.
J Food Sci ; 83(7): 1880-1887, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29846934

RESUMEN

Food waste is currently being generated at an increasing rate. One proposed solution would be to convert it to biopolymers for industrial applications. We recovered chitin from mushroom waste and converted it to chitosan to produce edible coatings. We then used layer-by-layer (LbL) electrostatic deposition of the polycation chitosan and the polyanion alginate to coat fruit bars enriched with ascorbic acid. The performance of the LbL coatings was compared with those containing single layers of fungal chitosan, animal origin chitosan and alginate. Bars containing alginate-chitosan LbL coatings showed increased ascorbic acid content, antioxidant capacity, firmness and fungal growth prevention during storage. Also, the origin of the chitosan did not affect the properties of the coatings. PRACTICAL APPLICATION: Mushroom stalk bases could be an alternative source for isolating chitosan with similar properties to animal-based chitosan. Also, layer-by-layer assembly is a cheap, simple method that can improve the quality and safety of fruit bars.


Asunto(s)
Agaricales/química , Alginatos/análisis , Quitosano/química , Aditivos Alimentarios/química , Frutas/química , Quitosano/aislamiento & purificación , Aditivos Alimentarios/aislamiento & purificación , Manipulación de Alimentos , Ácido Glucurónico/análisis , Ácidos Hexurónicos/análisis , Bocadillos
10.
Carbohydr Polym ; 174: 923-932, 2017 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-28821149

RESUMEN

Cellulose nanocrystals (CNCs) were extracted from Eucalyptus kraft pulp by sulfuric acid hydrolysis, and esterified with maleic anhydride (CNCMA). The incorporation of sulfate ester groups on the cellulose surface resulted in higher stability of the nanoparticles in aqueous suspensions and lower thermal stability. Then, PLA/CNC and PLA/CNCMA nanocomposites were successfully obtained by solution blow spinning (SBS) using dimethyl carbonate (DMC) as solvent. CNC and CNCMA indicated to be acting both as nucleating agents or growth inhibitors of PLA crystal and tends to favor the formation of PLA crystals of higher stability. A fraction of the nanocrystals indicate to be exposed on the surface of the PLA fibers, since the hydrophilicity of the composite films increased significantly. Such composites may have potential application as filtering membranes or adsorbents.

11.
J Food Sci ; 82(6): 1402-1411, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28471491

RESUMEN

The primary advantage of nanofibers over larger diameter fibers is the larger surface area to volume ratio. This study evaluated solution blow spinning (SBS) processing conditions for obtaining food-grade gelatin nanofibers from mammalian and fishery byproducts, such as pork skin gelatins (PGs) and high molecular weight fish skin gelatin (HMWFG). HMWFG had a highest intact collagen structure compared to PGs. PGs with different Bloom values, solution viscosities, and surface tensions were compared with HMWFG for their ability to produce nanofibers through SBS. Only HMWFG fibers were obtained irrespective of processing conditions, which looked like fluffy cotton candy. HMWFG nanofibers had round morphologies with a narrower diameter distribution and lower average fiber diameter (AFD) under medium gelatin concentrations, medium air pressures, and medium feed rates. The highest glass transition temperature (Tg ) values were obtained at medium concentrations, medium air pressure, and either high or low feed rate. The thinnest HMWFG nanofibers with an AFD of 80.1 nm and the highest Tg value of 59.0 °C could be formed by combining a concentration of 17.6% (w/v), an air pressure of 0.379 MPa, and a feed rate of 0.06 mL/min from the response surface analysis. HMWFG Brunauer, Emmett, and Teller surface area increased from 221 to 237 m2 /g, indicating their potential applicability for active compound carrier.


Asunto(s)
Manipulación de Alimentos , Gelatina/química , Nanofibras/química , Animales , Peces , Fenómenos Mecánicos , Reología , Piel , Soluciones , Porcinos , Viscosidad
12.
Carbohydr Polym ; 167: 97-104, 2017 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-28433182

RESUMEN

Brown mushroom (Agaricus bisporus) stalk bases from mushroom waste were treated with UV-B light to rapidly increase vitamin D2 content. Chitin was also recovered from this waste and converted into chitosan by N-deacetylation. FTIR spectra showed that the mushroom chitosan were similar to chitosan from animal sources. Chitosan films were prepared using high molecular weight (HW), low molecular weight (LW) and fungal chitosan. UV-B treated mushroom particles were also incorporated into fungal chitosan films. The fungal chitosan films showed similar density, porosity and water vapor barrier properties to the LW and HW chitosan films. However, fungal chitosan films were more hydrophobic and less flexible than the LW and HW chitosan films. Addition of mushroom particles did not significantly affect mechanical or water barrier properties of the fungal chitosan films.

13.
Plant J ; 91(3): 361-370, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28432803

RESUMEN

Due to a large and growing collection of genomic and experimental resources, Brachypodium distachyon has emerged as a powerful experimental model for the grasses. To add to these resources we sequenced 21 165 T-DNA lines, 15 569 of which were produced in this study. This increased the number of unique insertion sites in the T-DNA collection by 21 078, bringing the overall total to 26 112. Thirty-seven per cent (9754) of these insertion sites are within genes (including untranslated regions and introns) and 28% (7217) are within 500 bp of a gene. Approximately 31% of the genes in the v.2.1 annotation have been tagged in this population. To demonstrate the utility of this collection, we phenotypically characterized six T-DNA lines with insertions in genes previously shown in other systems to be involved in cellulose biosynthesis, hemicellulose biosynthesis, secondary cell wall development, DNA damage repair, wax biosynthesis and chloroplast synthesis. In all cases, the phenotypes observed supported previous studies, demonstrating the utility of this collection for plant functional genomics. The Brachypodium T-DNA collection can be accessed at http://jgi.doe.gov/our-science/science-programs/plant-genomics/brachypodium/brachypodium-t-dna-collection/.


Asunto(s)
Brachypodium/genética , ADN Bacteriano/genética , Plantas Modificadas Genéticamente/genética , Daño del ADN/genética , Genoma de Planta/genética , Genómica , Intrones/genética , Mutagénesis Insercional
14.
Carbohydr Polym ; 163: 101-107, 2017 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-28267486

RESUMEN

A hybrid catalyst was prepared using cellulose nanofibrils and magnetite to degrade organic compounds. Cellulose nanofibrils were isolated by mechanical defibrillation producing a suspension used as a matrix for magnetite particles. The solution of nanofibrils and magnetite was dried and milled resulting in a catalyst with a 1:1 ratio of cellulose and magnetite that was chemically and physically characterized using light, scanning electron and transmission electron microscopies, specific surface area analysis, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, catalytic potential and degradation kinetics. Results showed good dispersion of the active phase, magnetite, in the mat of cellulosic nanofibrils. Leaching and re-use tests showed that catalytic activity was not lost over several cycles. The hybrid material produced was tested for degradation of methylene blue dye in Fenton-like reactions resulting in a potential catalyst for use in degradation of organic compounds.


Asunto(s)
Celulosa/química , Óxido Ferrosoférrico/química , Residuos Industriales , Textiles , Purificación del Agua , Catálisis , Nanopartículas , Difracción de Rayos X
15.
J Food Sci ; 81(12): N3015-N3025, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27861896

RESUMEN

Zein fibers were successfully fabricated via solution blow spinning (SBS) using acetic acid as solvent. Surface tension, viscosity and modulus of zein solutions were respectively determined by force tensiometer and rheometer. Increases of these properties were observed with an increase of concentration from 20% to 35% (w/w). The fabrication conditions of zein fibers were initially investigated as a function of zein concentration (25% to 35% w/w), feed rate (0.04 to 0.1 mL/min) and air pressure (0.28 to 0.62 MPa). The average fiber diameter (AFD) ranged from 174 to 9595 nm based on scanning electron microscopy (SEM). A Box-Behnken experimental design (BBD) was further performed to identify and quantify the significance of above parameters. The statistical analysis showed that the linear coefficient of concentration, the quadratic term of concentration as well as the interaction between concentration and air pressure were demonstrated statistically significant. Optimal conditions, with an AFD of 138 nm, could be obtained in the SBS of zein fibers by combining a concentration of 23% (w/w), a feed rate of 0.04 mL/min and an air pressure of 0.38 MPa. The moisture sorption capacity of fibers increased slightly as AFD decreased from ∼550 to ∼200 nm, with an increase of BET surface area from 116.5 to 140.0 m2 /g.


Asunto(s)
Manipulación de Alimentos , Zeína/química , Antiinfecciosos/química , Antioxidantes/química , Preparaciones de Acción Retardada/química , Fenómenos Mecánicos , Microscopía Electrónica de Rastreo , Reología , Soluciones , Viscosidad
16.
Food Chem ; 191: 105-12, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26258708

RESUMEN

This study aims to evaluate the effects of polishing and parboiling on proximate composition, structure, phenolic compounds, antioxidant activity, cooking time and hardness of IAC-600 black rice cultivar and MPB-10 red rice lineage. Proximate analysis and light micrographs revealed higher migration of red rice proteins than black rice proteins to the endosperm as a result of parboiling. Parboiling reduced the ash content of red rice while no difference was determined in black rice. Gelatinized starch granules from both genotypes showed similar appearance. There was a decrease in relative crystallinity on both black and red rice subjected to parboiling, which was an indicative of crystallites disruption. Polishing removed more than 90% of free phenolics for both genotypes, while parboiling allowed the partial preservation of free phenolics content in polished rice. Parboiling induced an increase in the cooking time of red rice, but a decrease in the cooking time of black rice.


Asunto(s)
Culinaria , Oryza/química , Color , Genotipo , Dureza , Calor , Oryza/genética , Fenoles/análisis , Almidón/química
17.
J Nanosci Nanotechnol ; 15(1): 616-27, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26328414

RESUMEN

The present study reports on the development of hybrid poly(lactic acid) (PLA) fibres loaded with highly crystalline bacterial cellulose nanowhiskers (BCNW) by the novel solution blow spinning method. Furthermore, fibres with antimicrobial properties were generated by incorporating carvacrol and THC as antimicrobial agents and the biocide effect against Listeria monocytogenes was studied. Initially, PLA blow spun fibres containing BCNW were optimized in terms of morphology and thermal properties. The addition of BCNW was seen to significantly increase the viscosity and surface tension of solutions, restricting the capacity to form fibres for concentrations greater than 30 wt.-% BCNW. 15 wt.-% BCNW was selected as the optimum nanofiller loading as it led to the most uniform fibres morphology, with BCNW homogeneously distributed along the fibres' axis. Subsequently, carvacrol and THC were incorporated into the fibres to confer them with antimicrobial properties, although the hydrophobic PLA matrix did not provide an efficient release of the antimicrobials. Thus, hydrophilic substances were added in order to trigger the antimicrobials release through water sorption mechanisms. The addition of the BCNW filler was not seen to significantly increase the antimicrobial capacity of the fibres by itself and, hence, gelatin was added to help promoting further the hydrophylicity and biocide performance of the fibres. Nevertheless, for the more hydrophilic THC, the biocide capacity of the fibres with gelatin was accentuated further by the presence of the BCNW.


Asunto(s)
Antiinfecciosos/química , Ácido Láctico/química , Nanofibras/química , Nanotecnología/métodos , Polímeros/química , Antiinfecciosos/farmacología , Rastreo Diferencial de Calorimetría , Celulosa/química , Celulosa/metabolismo , Cimenos , Gluconacetobacter xylinus/química , Gluconacetobacter xylinus/metabolismo , Listeria monocytogenes/efectos de los fármacos , Monoterpenos/química , Monoterpenos/farmacología , Poliésteres , Viscosidad
18.
AANA J ; 82(3): 198-202, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25109157

RESUMEN

This prospective, experimental, mixed study determined whether there were differences in intraosseous (IO) and intravenous (IV) whole blood transfusion relative to hemolysis and transfusion time. Swine were assigned to the IV group (n = 6) with an 18-gauge catheter in the auricular vein or the IO group (n = 7) with a 15-gauge 10 needle in the proximal humerus. Following baseline specimen collection, 900 mL of blood was collected from each animal. The collected blood was autologously transfused by the IV or IO route using a pressure infusion bag inflated to 300 mm Hg, with immediate posttransfusion specimen collection. Hemolysis was defined by the amount of plasma free hemoglobin. Multivariate analysis of variance revealed no significant differences between groups relative to posttransfusion free hemoglobin or transfusion time (P = .065). The IV group's mean free hemoglobin level was 10.23 +/- 10.52 micromol/L; the IO group, 7.2 +/- 5.82 micromol/L. The IV group's mean transfusion time was 13.48 +/- 4.1 minutes; the IO group, 28.70 +/- 19.51 minutes. Intraosseous transfusion does not significantly increase hemolysis or transfusion time compared with IV transfusion. Clinically, it can take up to twice as long to transfuse 900 mL of blood IO compared with IV.


Asunto(s)
Transfusión Sanguínea/métodos , Hemólisis , Choque Hemorrágico/terapia , Administración Intravenosa , Animales , Infusiones Intraóseas , Modelos Animales , Proyectos Piloto , Porcinos , Factores de Tiempo
19.
J Food Sci ; 79(5): M903-10, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24749789

RESUMEN

UNLABELLED: Thyme essential oil (TEO) and apple skin polyphenols (ASP) are natural compounds considered as generally recognized as safe by FDA, with biological effects against bacteria and fungi. This work aimed to evaluate physical and antimicrobial properties of açaí edible films formulated with TEO and ASP at 3% and 6% (w/w) individually or combined at 3% (w/w) each. Physical properties studied include mechanical resistance, water vapor permeability (WVP), color, and thermal resistance. Antimicrobial activity against Listeria monocytogenes was determined using the overlay diffusion test. Addition of ASP resulted in improved mechanical properties. TEO at 6% (w/w) resulted in increased elongation. ASP films had significant higher WVP than control film. ASP films were lighter and had more red color than other films. Incorporation of ASP resulted in improved film thermal stability, whereas TEO caused rapid thermal decomposition. Presence of clusters was observed on the surface of films. Addition of ASP resulted in a smoother surface, whereas addition of TEO led to the formation of crater-like pits on the film surface. Açaí edible film incorporated with 6% (w/w) TEO presented the highest antimicrobial activity. However, both antimicrobials are necessary in the açaí films in order to obtain edible films with suitable physical-mechanical properties. The results of the present study showed that TEO and ASP can be used to prepare açaí edible films with adequate physical-mechanical properties and antimicrobial activity for food applications by direct contact. PRACTICAL APPLICATION: Developed açaí edible films presented antimicrobial activity against L. monocytogenes and good physical-mechanical properties, showing the potential use of açaí edible films in food preservation.


Asunto(s)
Antibacterianos/farmacología , Euterpe , Conservación de Alimentos/métodos , Listeria monocytogenes/efectos de los fármacos , Aceites Volátiles/farmacología , Extractos Vegetales/farmacología , Polifenoles/farmacología , Embalaje de Alimentos/métodos , Malus/química , Permeabilidad , Extractos Vegetales/química , Thymus (Planta)/química
20.
Pest Manag Sci ; 69(8): 975-82, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23355371

RESUMEN

BACKGROUND: Controlled-release formulations of bioactive agents are of increasing interest for effective pest control. Volatile 2-heptanone is a bioactive agent that has shown potential as a pesticide. The aim of this study was to investigate the kinetics of release of 2-heptanone incorporated into lipid films or composite solid lipid particle (SLP) films. RESULTS: Effective 2-heptanone diffusivity was estimated to be between 0.1 and 2.5 mm(2) day(-1) during the first week and between 0.05 and 0.1 mm(2) day(-1) during the next 5 weeks. The films that showed better retention of 2-heptanone were the paraffin lipid films. Inclusion of SLPs into paraffin films increased the release rate of 2-heptanone, mainly owing to a decrease in the film firmness as the composite SLP film became less crystalline and more brittle. In contrast, SLPs decreased the kinetics of 2-heptanone release in Acetem films owing to an increase in the film firmness. CONCLUSIONS: The results indicated that the use of SLPs as a method for controlled release can improve the delivery of the natural pesticide 2-heptanone if the SLPs have good compatibility with the matrix, leading to an increase in firmness of the films without increasing their porosity. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.


Asunto(s)
Química Farmacéutica/métodos , Preparaciones de Acción Retardada/química , Portadores de Fármacos/química , Cetonas/química , Lípidos/química , Química Farmacéutica/instrumentación , Difusión , Cinética
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