scholarly journals Preparation and characterization of corn starch/PVA/glycerol composite films incorporated with ε-polylysine as a novel antimicrobial packaging material

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 154-161 ◽  
Author(s):  
Gao Yurong ◽  
Li Dapeng

AbstractCorn starch/polyvinyl alcohol (PVA)/glycerol composite films incorporated with ε-polylysine were prepared, and their properties were investigated. The Fourier-transform infrared (FTIR) spectroscopy indicated that the interactions happened between the amino group of ε-polylysine and hydroxyl group starch/PVA composite films. X-ray diffraction (XRD) analysis showed that the addition of ε-polylysine decreased the intensity of all crystal peaks. Thermogravimetric (TGA) analysis suggested that ε-polylysine improved the thermal stability of composite films. Scanning electron microscopic (SEM) analysis showed that the upper surface of composite films incorporated with ε-polylysine presented more compact and flat surface. The antimicrobial activity of the composite film progressively increased with the increasing of ε-polylysine concentration (P < 0.05). The tensile strength, elongation at break and water absorption significantly increased, whereas water solubility decreased with the increasing of ε-polylysine concentration (P < 0.05). Therefore, the corn starch/PVA/glycerol composite films incorporated with ε-polylysine had good mechanical, physical and antimicrobial properties and could have potential application as a novel antimicrobial packaging material.

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 985 ◽  
Author(s):  
Diana Paiva ◽  
André Pereira ◽  
Ana Pires ◽  
Jorge Martins ◽  
Luísa Carvalho ◽  
...  

Microparticles of corn starch and chitosan crosslinked with glutaraldehyde, produced by the solvent exchange technique, are studied as reinforcement fillers for thermoplastic corn starch plasticized with glycerol. The presence of 10% w/w chitosan in the microparticles is shown to be essential to guaranteeing effective crosslinking, as demonstrated by water solubility assays. Crosslinked chitosan forms an interpenetrating polymer network with starch chains, producing microparticles with a very low solubility. The thermal stability of the microparticles is in agreement with their polysaccharide composition. An XRD analysis showed that they have crystalline fraction of 32% with Va-type structure, and have no tendency to undergo retrogradation. The tensile strength, Young’s modulus, and toughness of thermoplastic starch increased by the incorporation of the crosslinked starch/chitosan microparticles by melt-mixing. Toughness increased 360% in relation to unfilled thermoplastic starch.


Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 97
Author(s):  
Luyu Mei ◽  
Liuxin Shi ◽  
Xiuli Song ◽  
Su Liu ◽  
Qiang Cheng ◽  
...  

In this study, carboxymethyl cellulose (CMC) films containing 1%, 2%, and 3% Chinese fir essential oil (CFEO) were prepared. The mechanical, optical, physical, microstructural, thermal stability and antimicrobial properties of the films were studied. A traditional steam distillation method was applied for CFEO extraction, in which 35 volatile components were identified. The research results showed that the CMC film mixed with 1% CFEO had the highest tensile strength (TS) and elongation at break (EB), whereas the flexibility was decreased under higher concentrations of CFEO. However, the film’s degree of transparency under controlled humidity did not decrease with an increase in CFEO concentration; thus, the sensory evaluation was not adversely effect. Furthermore, the thickness and the water solubility (WS) of film increased after the addition of CFEO. The thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) results indicated that the thermal stability of the CMC-CFEO films improved. Moreover, the composite films showed excellent inhibitory effects toward Gram-positive bacterias and Penicillium citrinum. The treatments of grapes with CMC + 1% CFEO resulted in the best properties during storage. CMC-CFEO film can be a candidate for food packaging due to its excellent performances.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Anita Solanki ◽  
Dipika Rathod ◽  
Illa C. Patel ◽  
Jitendriya Panigrahi

Abstract Background Celastrus paniculatus Willd. is a rich source of numerous active constituents such as celapanigin, celapagin, malkangunin, celapanin, zeylasteral, pristimerin, and zeylasterone which render medicinal properties to its various parts. Therefore, the present work provides a protocol for the synthesis of AgNPs from in vivo leaf and in vitro developed callus extract of C. paniculatus and both the extracts have great antibacterial potential, which may give immense support for the drug preparation using AgNPs prepared from this valuable medicinal plant. Results High frequencies of calli induced from leaves and its counterpart, i.e., the natural part leaf were selected as the experimental materials for the green synthesis. The collected data exhibited gradual color variations started with whitish color, creamish, and after 8 weeks it ultimately turns into a solid mass of brownish callus. The silver nanoparticles (AgNPs) were synthesized using in vivo fresh leaves and in vitro developed callus extracts with an indication of brown colored complex. Further confirmation of AgNPs synthesis in both the samples was done using UV-visible spectral analysis followed by X-ray diffraction (XRD) analysis, Fourier transformation infrared spectroscopy (FTIR), and scanning electron microscopic (SEM) analysis. Conclusion The antibacterial activity of both extracts reflected the presence of the zone of inhibition in both gram-positive and gram-negative bacteria. AgNPs derived from callus extract showed better results with 24.00 ± 1.00 mm zones of inhibition. This protocol deserves the recognition of the antibacterial potential of AgNPs synthesized from CP plant extracts.


2013 ◽  
Vol 873 ◽  
pp. 669-675
Author(s):  
Fang Yi Li ◽  
Kai Kai Guan ◽  
Peng Liu ◽  
Jian Feng Li ◽  
Gang Li

Excellent state of material molding and microstructure can enhance the physical properties of biomass packaging material based fiber and starch efficiently. Therefore, the main raw materials were further processed in this study and processing technologies were improved accordingly. Corn starch was plasticized by ethylene glycol and glycerol. Straw fiber was further processed through washing with water and alkaline treatment. Foam molding tests were conducted according to the different treatment combinations, so were the tests of static compression, tensile properties and packages stacking. The results of quantitative analysis showed that the treated materials had a more notable influence on the comprehensive performance. The optimum processing technology about raw materials corresponding to specific mechanical property is obtained according to the tests analysis. Through SEM analysis, the influence mechanism of starch, fiber processing on the micro-structure of material and outer physical and chemical properties were also studied.


2020 ◽  
Vol 23 (5) ◽  
pp. 147-151
Author(s):  
Ansharullah Ansharullah ◽  
Nur Muhammad Abdillah Saenuddin ◽  
RH Fitri Faradilla ◽  
Asranuddin Asranudin ◽  
Asniar Asniar ◽  
...  

This study was aimed to examine the production of microcrystalline cellulose (MCC) from tapioca solid waste (TSW), using HCl hydrolysis with various concentrations, i.e., 2 N, 2.5 N, 3 N, and 3.5 N. MCC was produced by delignifying the TSW with NaOH 20%, and bleaching with NaOCl 3.5% to produce α-cellulose, and subsequently hydrolyzing α-cellulose with three different HCl concentrations to produce MCC. The physicochemical properties of MCC were then analyzed, including Scanning Electron Micrograph (SEM), X-ray diffraction (XRD), and FTIR spectra. The results showed that hydrolysis with 2.0 N HCl resulted in a higher yield of 61.28%, α-cellulose content of 56.33%, moisture 6.25%, pH of 6.54; ash 0.23%, and water solubility 0.34%. SEM analysis showed the morphology and size of the MCC produced were like those of a commercial MCC (Avicel PH101), while the XRD analysis showed the higher concentration of HCl gave rise to an increased crystalline index. FT-IR spectrum analysis indicated that TSW, MCC produced, and commercial MCC had similar functional groups.


2020 ◽  
Vol 12 (4) ◽  
pp. 530-534
Author(s):  
Mala Mathiyazhagan ◽  
Jeevarani John Raj ◽  
Jeya Jothi Gabriel

The benefit of utilizing plants for the synthesis of nanoparticles include a broad variability of metabolites that may aid in reduction, easily available as well as safe to handle. Boerhavia diffusa L. is known as punarnava, possessing anti-inflammatory, diuretic activities and is being used for the common clinical problems such as nephrotic edema, syndrome and ascites resulting from early cirrhosis of the liver and chronic peritonitis. The present study aims at biosynthesis of silver fabricated nanoparticles with the aqueous extracts of B. diffusa leaves and roots by using 1 mM AgNO3 . Preliminary confirmation of silver nanoparticles was done by using Ultra Violet Visual (UV-VIS) Spectrophotometer. The biomolecules were responsible for reducing the Ag+ to Ag0 which was identified by Fourier Transform Infra-Red (FTIR). The nanoparticles were subjected to Scanning Electron Microscopic (SEM) analysis to detect the Size and morphology of the particles. The nanoscale level (< 100 nm) of spherical shaped aggregates was identified. Antimicrobial assays were carried out with the selected clinical isolates using disc diffusion method and the notable inhibitory zones were observed against all the isolates at very low concentration.


2020 ◽  
Vol 16 (4) ◽  
pp. 578-583
Author(s):  
Muhammad Asif Hussain ◽  
Adnan Maqbool ◽  
Abbas Saeed Hakeem ◽  
Fazal Ahmad Khalid ◽  
Muhammad Asif Rafiq ◽  
...  

Background: The development of new bioimplants with enhanced mechanical and biomedical properties have great impetus for researchers in the field of biomaterials. Metallic materials such as stainless steel 316L (SS316L), applied for bioimplants are compatible to the human osteoblast cells and bear good toughness. However, they suffer by corrosion and their elastic moduli are very high than the application where they need to be used. On the other hand, ceramics such as hydroxyapatite (HAP), is biocompatible as well as bioactive material and helps in bone grafting during the course of bone recovery, it has the inherent brittle nature and low fracture toughness. Therefore, to overcome these issues, a hybrid combination of HAP, SS316L and carbon nanotubes (CNTs) has been synthesized and characterized in the present investigation. Methods: CNTs were acid treated to functionalize their surface and cleaned prior their addition to the composites. The mixing of nano-hydroxyapatite (HAPn), SS316L and CNTs was carried out by nitrogen gas purging followed by the ball milling to insure the homogeneous mixing of the powders. In three compositions, monolithic HAPn, nanocomposites of CNTs reinforced HAPn, and hybrid nanocomposites of CNTs and SS316L reinforced HAPn has been fabricated by spark plasma sintering (SPS) technique. Results: SEM analysis of SPS samples showed enhanced sintering of HAP-CNT nanocomposites, which also showed significant sintering behavior when combined with SS316L. Good densification was achieved in the nanocomposites. No phase change was observed for HAP at relatively higher sintering temperatures (1100°C) of SPS and tricalcium phosphate phase was not detected by XRD analysis. This represents the characteristic advantage with enhanced sintering behavior by SPS technique. Fracture toughness was found to increase with the addition of CNTs and SS316L in HAPn, while hardness initially enhanced with the addition of nonreinforcement (CNTs) in HAPn and then decrease for HAPn-CNT-SS316L hybrid nanocomposites due to presence of SS316L. Conclusion: A homogeneous distribution of CNTs and SPS technique resulted in the improved mechanical properties for HAPn-CNT-SS316L hybrid nanocomposites than other composites and suggested their application as bioimplant materials.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1132
Author(s):  
Eduardo Lanzagorta Garcia ◽  
Olivia A. Attallah ◽  
Marija Mojicevic ◽  
Declan M Devine ◽  
Margaret Brennan Fournet

An innovative antimicrobial technology for plastic surfaces is presented. We report the synthesis and scale-up of triangular silver nanoplates (TSNPs) and their integration into polycaprolactone (PCL) and polylactic acid (PLA) polymers through a solvent-casting technique. The TSNPs have a high geometric aspect ratio and strong local surface plasmon resonance (LSPR) response, which provides an effective tool for monitoring their integrity during processing and integration with the biodegradable plastics. An aqueous-based seed-mediated chemical method was used to synthesize the TSNPs, and characterisation was carried out using TEM and UV (Ultraviolet)-VIS (Visible) spectroscopy to measure LSPR profiles. The UV-VIS spectra of silver seeds and TSNPs exhibited characteristic peaks at 395 and 600 nm respectively. Synthesized TSNPs were coated with thiol-terminated polyethylene glycol (SH-PEG) and transferred into chloroform in order to effect compatibility with PCL and PLA. TSNP/PCL and TSNP/PLA composite films were prepared by solvent casting. The morphological structure, thermal, mechanical, and antimicrobial properties of the TSNP-incorporated composite films were evaluated. Results showed the TSNP-treated films had a rougher surface than the bare films. Insignificant changes in the thermal properties of TSNP-treated films compared to bare ones were also observed, which indicated the thermal stability of the composite films. The tensile strength and antimicrobial properties of the composite films were increased after TSNP incorporation. TSNP/PCL and TSNP/PLA films exhibited improved antimicrobial activity against Escherichia coli and Staphylococcus aureus with antimicrobial effect (AE) values ranging between 0.10 and 0.35. The obtained results and demonstrated TSNP production scalability validate the TSNP treated PCL and PLA films as a composite material with desirable antimicrobial effect for wide-ranging surface applications.


2020 ◽  
Vol 16 (8) ◽  
Author(s):  
Jiabao Cao ◽  
Baoxin Lu ◽  
Dongjie Zhang ◽  
Longkui Cao ◽  
Xia Wang ◽  
...  

AbstractThe present study was carried out to produce a high quality puffed infant rice cereal from rice and mung bean through extrusion technology. Experiments were designed using 3 independent variables (i. e. 14–18% feed moisture, 400–550 r/min screw speed and 125–175 °C barrel temperature) and 3 response variables (i. e. bulk density, water solubility index and degree of gelatinisation) at five different levels of central composite rotatable design (CCRD). The results of optimization demonstrated that 14% feed moisture, 400 r/min screw speed and 175 °C barrel temperature could generate rice-mungbean extrudates with desirable functional properties. The selected extrudate samples were further examined using scanning electron microscope (SEM), rapid viscosity analyzer (RVA), Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD) analysis, in vitro digestibility and fundamental nutrient analysis. Notably, the initial oval-shaped particle structure of starch in the raw materials disappeared, the surface debris and roughness increased, and the density decreased. The time required for the gelatinization of puffed infant rice cereal was the shortest, which was in agreement with the positioning of ready-to-eat weaning food for infants. Moreover, the puffed infant rice cereal displayed higher peak viscosity and breakdown value, smaller retrogradation value and greater top taste value compared to the commercial infant rice cereal. Besides maintaining the initial characteristic peak of starch, the puffed infant rice cereal demonstrated characteristic absorption peaks of COO- in the vicinity of 1546 cm−1 and 1437 cm−1, indicating the formation of carboxylate during extrusion. In addition, the puffed infant rice cereal exhibited firm diffraction peaks at the diffraction angles of 7.4°, 12.5° and 20.5°, indicating that a certain amount of starch changed from type A to type V. Furthermore, the digestive rate of puffed infant rice cereal was higher than that of commercial infant cereal (90.21 versus 86.96%, respectively; p < 0.05). Altogether, our findings reveal that the developed puffed infant rice cereal meets the standards set by the Codex Alimentarius Commission (CAC; 74-1981).


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