scholarly journals Fungicides Films of Low-Density Polyethylene (LDPE)/Inclusion Complexes (Carvacrol and Cinnamaldehyde) Against Botrytis Cinerea

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 795 ◽  
Author(s):  
Daniel Canales ◽  
Lissette Montoille ◽  
Lina M. Rivas ◽  
J. Andrés Ortiz ◽  
Mauricio Yañez-S ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Essential Oil ◽  
Inclusion Complexes ◽  
Polymer Matrix ◽  
Active Agent ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Active Compounds ◽  
Scanning Electron

Low density polyethylene (LDPE) films were prepared with the incorporation of natural agents (carvacrol and trans-cinnamaldehyde) by the melting process. The co-precipitation method was used successfully to complex the carvacrol or trans-cinnamaldehyde with β-cyclodextrin (β-CD). The active compounds encapsulated in β-CD achieved ca. 90% encapsulation efficiency (E.E.). The inclusion complex studied by scanning electron microscopy (SEM) found particles of different sizes, ca. 4 μm. The active compounds were added directly (1 and 5 wt %) into the polymer matrix, yielding LDPE + carvacrol and LDPE + cinnamaldehyde films. The active compounds encapsulated in β-cyclodextrin (β-CD) were added to LDPE, yielding LDPE + β-CD-carvacrol and LDPE + β-CD-cinnamaldehyde films. The incorporation of carvacrol and trans-cinnamaldehyde, and their corresponding inclusion complexes with β-cyclodextrin, did not affect the thermal properties of LDPE. The microcapsules distributed in all polymer matrices had sizes of 5–20 μm as shown by scanning electron microscopy (SEM). In terms of mechanical properties, the polymers showed a slight decrease of Young’s modulus (12%) and yield stress compared (14%) to neat LDPE. This could be due to the essential oil acting as a plasticizer in the polymer matrix. The LDPE + carvacrol and LDPE + cinnamaldehyde films had the capacity to inhibit fungi by 99% compared to neat LDPE. The effectiveness against fungi of LDPE+β-CD + active agent was slower than by the direct incorporation of the essential oil in the LDPE in the same amount of active agent. The biocidal properties were related to the gradual release of active compound from the polymer. The results confirm the applicability of carvacrol, trans-cinnamaldehyde, and their corresponding inclusion complexes in active packaging, as well as their use in the food delivery industry.

scholarly journals Low-density polyethylene films incorporated with silver nanoparticles to promote antimicrobial efficiency in food packaging

2019 ◽  
Vol 26 (4) ◽  
pp. 353-366
Author(s):  
Sabrina da Costa Brito ◽  
Joana D Bresolin ◽  
Kátia Sivieri ◽  
Marcos D Ferreira
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Food Packaging ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Bacterial Cells ◽  
Scanning Calorimetry ◽  
Polyethylene Films ◽  
Scanning Electron

Technological innovations in packaging are intended to prevent microbiological contaminations for ensuring food safety and preservation. In this context, researchers have investigated the antimicrobial effect of low-density polyethylene films incorporated with the following concentrations of silver nanoparticles: 1.50, 3.75, 7.50, 15.00, 30.00, 60.00, and 75.00 µg/ml. The films were characterized using field emission gun scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetry, and differential scanning calorimetry. From the results of these techniques, it could be concluded that the silver nanoparticles incorporated in the low-density polyethylene films did not influence their physical, chemical, and thermal properties. The direct contact assays, shake-flask assays, and bacterial images obtained using scanning electron microscopy were used to analyze the antimicrobial activity of the films. In the microbial analyses, it was verified that the nanostructured films exhibited antimicrobial properties against all the microorganisms studied, although more notably for fungi and Gram-negative bacteria than the Gram-positive bacteria. Moreover, it was discovered that the packages, in which silver nanoparticles were incorporated, inhibited the growth and reproduction of bacterial cells during the early stages. These results suggest that the extruded low-density polyethylene films incorporated with silver nanoparticles may be an essential tool for improving food quality and safety.

Development and Characterization of an Antimicrobial Packaging Film Coating Containing Nisin for Inhibition of Listeria monocytogenes

2004 ◽  
Vol 67 (3) ◽  
pp. 475-479 ◽  
Author(s):  
JENNIFER L. GROWER ◽  
KAY COOKSEY ◽  
KELLY J. K. GETTY
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Rate ◽  
Film Coating ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Water Vapor Transmission Rate ◽  
Packaging Film ◽  
Water Vapor Transmission ◽  
Scanning Electron

The purpose of this study was to develop and characterize a packaging film coating containing nisin. A spot-on-lawn assay was used to determine the effect of acid type (ascorbic, acetic, hydrochloric, lactic) and nisin level (equal increments from 10,000 IU to 9 IU) to be used in the formulation of the film coating. Zones of inhibition were measured after incubation on tryptic soy agar (37°C, 48 h). Low-density polyethylene films coated with differing levels of nisin were characterized by field emission scanning electron microscopy, tensile strength, elongation, and water vapor transmission rate. The MIC of nisin in solution was 157 mg/ml. All acids were equally inhibitory (P > 0.05), but acetic acid produced the largest zone of inhibition (21 mm). Field emission scanning electron microscopy confirmed that the cloudy appearance of the films was due to sodium chloride found in the commercially prepared nisin. Tensile strength increased as nisin concentration increased, which also corresponded to increasing film thickness. The nisin coatings (10,000 and 2,500 IU/ml) did not have a significant effect (P > 0.05) on the water vapor transmission rate of the low-density polyethylene film.

Morphology of Silicone/Organic Blends

1998 ◽  
Vol 4 (S2) ◽  
pp. 832-833
Author(s):  
Hongxi Zhang ◽  
Wei Chen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Density Polyethylene ◽  
Dispersed Phase ◽  
Low Density ◽  
Melt Index ◽  
Phase Dispersion ◽  
Enhanced Properties ◽  
Thermoplastic Resins ◽  
Scanning Electron

Silicone materials may be incorporated into organic thermoplastic resins to provide enhanced properties. Good dispersion of silicone with plastics is believed to be one of the keys to control the applications of these multiphase blends. In this study, we investigated the morphologies of mechanically mixed silicone/organic blends using scanning electron microscopy (SEM). Results provide an important piece of information that the optimum silicone phase dispersion can be achieved by matching the viscosities of the blend components.Most silicone and organic polymers are thermodynamically immiscible, forming multiphase structures for their blends. For example, a blend consisting of 90 wt% polydimethylsiloxane (PDMS) and 10% low density polyethylene (LDPE) was revealed by SEM to have a multiphase structure shown in Figure 1A where the PDMS was a Dow Corning® 3-5016 silanol-terminated siloxane fluid that forms the dispersed phase and the LDPE a Dow Chemical polyethylene having a melt index of 4.

Kaolinite dispersion in cassava starch-based composite films: a photonic microscopy and X-ray tomography study

2018 ◽  
Vol 38 (7) ◽  
pp. 641-647
Author(s):  
Jean Aimé Mbey ◽  
Fabien Thomas ◽  
Sandrine Hoppe
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dimethyl Sulfoxide ◽  
Polymer Matrix ◽  
Composite Films ◽  
Cassava Starch ◽  
X Ray ◽  
Clay Dispersion ◽  
Combined Use ◽  
Scanning Electron

Abstract In the present study, a combined use of photonic microscopy, scanning electron microscopy and 3D X-ray tomography is carried out in order to analyze the dispersion and the distribution of raw and dimethyl sulfoxide (DMSO)-intercalated kaolinite used as filler in cassava starch-based films. It is shown that the association of these techniques allows a valuable analysis of clay dispersion in polymer-clay composite films. In the case of kaolinite-starch composite films on which this study is focused, it is obvious that previous intercalation of kaolinite with DMSO is an efficient way to improve dispersion and distribution of kaolinite in a starch polymer matrix.

Development of Alginate Based Active Films Containing Turmeric Essential Oil

2020 ◽  
Vol 861 ◽  
pp. 378-382
Author(s):  
Sophoan Phal ◽  
Muhammad Rafiullah Khan ◽  
Pattarin Leelaphiwat ◽  
Vanee Chonhenchob
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Water Vapor ◽  
Essential Oil ◽  
Sem Analysis ◽  
Film Properties ◽  
Elongation At Break ◽  
Control Film ◽  
Scanning Electron

Sodium alginate based films containing turmeric oil (TEO) at different concentrations (1, 2 and 3%) were developed. The film with no TEO was used as control. Incorporation of TEO had the effects on the film properties. With increasing TEO concentrations, thickness, elongation at break, permeability of oxygen and water vapor of the films significantly (p ≤ 0.05) increased. Whereas moisture content, tensile strength and modulus of elasticity significantly (p ≤ 0.05) decreased. Scanning electron microscopy (SEM) analysis showed more numerous pores and rougher surface of the antifungal films than the control film.

scholarly journals Micromorphology of Glandular hairs, Biological Activity and Composition of the Essential Oil of Tanacetum fisherae (Asteraceae-Anthemideae) from Iran

2011 ◽  
Vol 6 (2) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Peyman Rajaei ◽  
Taher Nejadsattari ◽  
Ali Asghar Maassoumi ◽  
Valiollah Mozaffarian ◽  
Ali Sonboli
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Biological Activity ◽  
Essential Oil ◽  
New Record ◽  
Antimicrobial Property ◽  
Microbial Strains ◽  
Total Oil ◽  
Main Component ◽  
Scanning Electron

The essential oil was obtained from the aerial flowering parts of Tanacetum fisherae, a new record from Iran, by hydrodistillation and analyzed by GC and GC-MS. Eleven components representing 99.9% of the total oil were identified. 1,8-Cineole (79.9%) was characterized as the principal compound. The essential oil and its main component were tested against nine microbial strains. The result of the bioassays revealed that the oil possess potent antimicrobial property. This may be associated due to the presence of 1,8-cineole in the oil which tested individually and its high activity was observed. Micromorphological studies of hairs by scanning electron microscopy (SEM) exhibited the presence of abundant sessile capitate glandular and medifixed T-shaped eglandular trichomes on the leaves, flowers and achene, giving useful diagnostic characters for identification of this medicinal plant.

Morphological Characterization of a Sustained-Release Drug Implant by Scanning Electron Microscopy, Polarized Light Microscopy and Image Analysis

1998 ◽  
Vol 4 (S2) ◽  
pp. 932-933
Author(s):  
J.P. Neilly ◽  
J.S. Deng ◽  
J.L. House ◽  
J.A. Fagerland
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sustained Release ◽  
Light Microscopy ◽  
Polymer Matrix ◽  
Polarized Light ◽  
Polarized Light Microscopy ◽  
Sustained Drug Release ◽  
Gentamicin Sulfate ◽  
Scanning Electron

Septacin is a sustained-release antibiotic currently under development by the Hospital Products Division of Abbott Laboratories. The product is designed to be used as an anti-infective implant in orthopedic surgical procedures with a sustained drug release for up to six weeks in vivo. It consists of gentamicin sulfate formulated with a bioerodable polyanhydride copolymer. The polymer is biodegradable and has been approved by the FDA for human clinical trials. The final product is obtained by mixing 20% gentamicin sulfate with molten polymer and injection molding it to form cylindrical Septacin beads.The microstructure of drug particles and polymer matrix is critical to the performance of sustained release products, thus scanning electron microscopy (SEM) and polarized light microscopy (PLM) were utilized in this study. SEM has proven useful for evaluating the microstructure of drug formulations3 and was used to examine the drug-polymer matrix structure. Average drug particle size and distribution were determined, and the drug-polymer boundary was evaluated.

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