Rheological performance of film-forming solutions and barrier properties of films fabricated from cold plasma-treated high methoxyl apple pectin and crosslinked by Ca2+: Impact of plasma treatment voltage.

Sustainable and "green" technologies, such as cold plasma are gaining attention in recent times for improving the functional properties of hydrocolloids. Chemical modifications of hydrocolloids require several chemicals and solvents, which are not environment-friendly. The major objective of the study was to understand the impact of plasma treatment (170-230 V|15 min) on the rheology of film-forming solutions (FFS) and the barrier properties of pectin films. The film-forming properties of plasma-treated pectin were investigated in the presence of two plasticizers, namely, glycerol and polyethylene glycol (PEG) 400. The effects of cross-linking by CaCl2 on the rheology of FFS and barrier properties of the films were discussed. A voltage-dependent decrease in the apparent viscosity of FFS was observed. The viscoelastic properties of the FFS were enhanced due to cross-linking. Glycerol exhibited a better plasticizing effect than PEG. Cross-linking and increasing voltage synergistically contributed towards lower oxygen and carbon dioxide transmission rates. The moisture sorption rate and capacity of the films increased with the voltage of the treatment. The resistance to extension of the films made from glycerol and PEG decreased with voltage, with no significant change in extensibility. On the other hand, the cross-linking by Ca2+ and plasma treatment enhanced the resistance to extension for the films made from both the plasticizers. While the increasing hydrophilicity and opacity of the films were a major drawback of plasma modification, the increase in UV barrier property of the films was an advantage of the modification.

New Active Packaging Based on Biopolymeric Mixture Added with Bacteriocin as Active Compound.

The objective of this work was to develop a chitosan/agar-agar bioplastic film incorporated with bacteriocin that presents active potential when used as food packaging. The formulation of the film solution was determined from an experimental design, through the optimization using the desirability function. After establishing the concentrations of the biopolymers and the plasticizer, the purified bacteriocin extract of Lactobacillus sakei was added, which acts as an antibacterial agent. The films were characterized through physical, chemical, mechanical, barrier, and microbiological analyses. The mechanical properties and water vapor permeability were not altered by the addition of the extract. The swelling property decreased with the addition of the extract and the solubility increased, however, the film remained intact when in contact with the food, thus allowing an efficient barrier. Visible light protection was improved by increased opacity and antibacterial capacity was effective. When used as Minas Frescal cream cheese packaging, it contributed to the increase of microbiological stability, showing a reduction of 2.62 log UFC/g, contributing a gradual release of the active compound into the food during the storage time. The film had an active capacity that could be used as a barrier to the food, allowing it to be safely packaged.

Developments of biobased plasticizers for compostable polymers in the green packaging applications: A review.

The demand for biobased materials for various end-uses in the bioplastic industry is substantially growing due to increasing awareness of health and environmental concerns, along with the toxicity of synthetic plasticizers such as phthalates. This fact has stimulated new regulations requiring the replacement of synthetic conventional plasticizers, particularly for packaging applications. Biobased plasticizers have recently been considered as essential additives, which may be used during the processing of compostable polymers to enormously boost biobased packaging applications. The development and utilization of biobased plasticizers derived from epoxidized soybean oil, castor oil, cardanol, citrate, and isosorbide have been broadly investigated. The synthesis of biobased plasticizers derived from renewable feedstocks and their impact on packaging material performance have been emphasized. Moreover, the effect of biobased plasticizer concentration, interaction, and compatibility on the polymer properties has been examined. Recent developments have resulted in the replacement of synthetic plasticizers by biobased counterparts. Particularly, this has been the case for some biodegradable thermoplastics-based packaging applications.

Design and synthesis of transparent and flexible nanofibrillated cellulose films to replace petroleum-based polymers.

Nanofibrillated cellulose films have garnered attention due to their interesting proprieties such as transparency and high mechanical strength. However, they are brittle, very hydrophilic, which is decreasing their potential applications. We have successfully achieved a simple and effective chemical modification based on polymer grafting and through plasticizer additions to increase the performance of the films as well as to improve the compatibility within conventional polymer. A preliminary study shows the possibility of using this film as an interlayer in safety glazing and/or bulletproof glass with polyvinyl butyral (PVB). The modified NFC films displays high optical transmittance (93 %), increases tensile stretch and is more hydrophobic (83°). A higher flexibility was also achieved, as the film was greatly stretched and bended without cracking or breaking. The NFC / PVB composite has three times more elongation at break, 13 % more specific energy absorbed with a half-tensile stress compared to an interlayer of PVB.

Liquefaction of starch using solid-acid catalysts derived from spent coffee for the production of plasticized poly (vinyl alcohol) films.

This paper reports a strategy for preparing polyether polyols from corn starch, with (i) a mixture of polyethylene glycol 400 and glycerin (7:3, w/w) as the liquefying solvent and (ii) a spent-coffee-derived solid-acid catalyst (SC-SAC) (1:10, w/w, SC-SAC/starch) at 433 K for 1.5 h, under which conditions the liquefaction yield exceeded 99 %. The SC-SAC was prepared via hydrothermal carbonization at 453 K for 12 h, followed by sulfonation with H2SO4 at 343 K for 10 h. The liquefied starch product (SLP) was then used to plasticize poly(vinyl alcohol) (PVA) films with various mixing ratios. The optimal 0.4 SLP/PVA blend film exhibited good mechanical properties (tensile strength 38.07 MPa, elongation at break 1199 %), good transparency, and excellent flexibility. The results highlight the possibility of using SLP/PVA films in the development of degradable packaging materials.

Amylose/cellulose nanofiber composites for all-natural, fully biodegradable and flexible bioplastics.

Thermoplastic, polysaccharide-based plastics are environmentally friendly. However, typical shortcomings include lack of water resistance and poor mechanical properties. Nanocomposite manufacturing using pure, highly linear, polysaccharides can overcome such limitations. Cast nanocomposites were fabricated with plant engineered pure amylose (AM), produced in bulk quantity in transgenic barley grain, and cellulose nanofibers (CNF), extracted from agrowaste sugar beet pulp. Morphology, crystallinity, chemical heterogeneity, mechanics, dynamic mechanical, gas and water permeability, and contact angle of the films were investigated. Blending CNF into the AM matrix significantly enhanced the crystallinity, mechanical properties and permeability, whereas glycerol increased elongation at break, mainly by plasticizing the AM. There was significant phase separation between AM and CNF. Dynamic plasticizing and anti-plasticizing effects of both CNF and glycerol were demonstrated by NMR demonstrating high molecular order, but also non-crystalline, and evenly distributed 20 nm-sized glycerol domains. This study demonstrates a new lead in functional polysaccharide-based bioplastic systems.

Development and Characterization of an Orodispersible Film for Vitamin D3 Supplementation.

Vitamin D plays a crucial and very well-known role in regulation of calcium homeostasis and bone metabolism and mineralization. However, a huge and more recent body of evidence supports the positive influence of vitamin D on the regulation of immune response, ranging from protection against respiratory tract infections to prevention and management of asthma. Nevertheless, vitamin D deficiency is a very common condition and there is an increasing need for suitable products for proper supplementation, allowing good compliance also in specific populations. Orally disintegrating tablets (ODT) were first developed to overcome the difficulty experienced by pediatric and geriatric patients of swallowing traditional oral dosage forms and, recently, orodispersible films (ODF) are gaining popularity as novel dosage form for assuming active pharmaceutical ingredients, vitamins, and ingredients for food supplements. This study describes a 2000 IU Vitamin D3 ODF for daily intake, consisting of hydrophilic polymers and suitable excipients, manufactured by film-casting process. Elongation-at-break (E%), Young's modulus (Y), and tensile strength (TS) were investigated using a dynamometer. Chemical stability was evaluated assaying the vitamin D3 in the films stored at different environmental conditions. In addition, in vitro disintegration and dissolution studies were performed. Correlation existed between the mechanical properties of the film and the residual water, acting as plasticizer. The stability study showed that vitamin D3 assay was ≥90% also after 3 months at 40 °C. The film disintegrated in less than 1 min and the vitamin D3 released was ≥75% after 15 min. An ODF with suitable properties can be manufactured and used as innovative dosage form for vitamin D3 food supplements.

High-Toughness Poly(Lactic Acid)/Starch Blends Prepared through Reactive Blending Plasticization and Compatibilization.

In this study, poly(lactic acid) (PLA)/starch blends were prepared through reactive melt blending by using PLA and starch as raw materials and vegetable oil polyols, polyethylene glycol (PEG), and citric acid (CA) as additives. The effects of CA and PEG on the toughness of PLA/starch blends were analyzed using a mechanical performance test, scanning electron microscope analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy, X-ray diffraction, rheological analysis, and hydrophilicity test. Results showed that the elongation at break and impact strength of the PLA/premixed starch (PSt)/PEG/CA blend were 140.51% and 3.56 kJ·m-2, which were 13.4 and 1.8 times higher than those of pure PLA, respectively. The essence of the improvement in the toughness of the PLA/PSt/PEG/CA blend was the esterification reaction among CA, PEG, and starch. During the melt-blending process, the CA with abundant carboxyl groups reacted in the amorphous region of the starch. The shape and crystal form of the starch did not change, but the surface activity of the starch improved and consequently increased the adhesion between starch and PLA. As a plasticizer for PLA and starch, PEG effectively enhanced the mobility of the molecular chains. After PEG was dispersed, it participated in the esterification reaction of CA and starch at the interface and formed a branched/crosslinked copolymer that was embedded in the interface of PLA and starch. This copolymer further improved the compatibility of the PLA/starch blends. PEGs with small molecules and CA were used as compatibilizers to reduce the effect on PLA biodegradability. The esterification reaction on the starch surface improved the compatibilization and toughness of the PLA/starch blend materials and broadens their application prospects in the fields of medicine and high-fill packaging.

Averrhoa bilimbi pectin-based edible films: Effects of the linearity and branching of the pectin on the physicochemical, mechanical, and barrier properties of the films.

The potential of Averrhoa bilimbi pectin (ABP) as a source of biopolymer for edible film (EF) production was explored, and deep eutectic solvent (DES) (1% w/w) containing choline chloride-citric acid monohydrate at a molar ratio of 1:1 was used as the plasticizer. The EF-ABP3:1, which was produced from ABP with large branch size, showed a higher value of melting temperature (175.30 °C), tensile stress (7.32 MPa) and modulus (33.64 MPa). The EF-ABP3:1 also showed better barrier properties by obtaining the lowest water vapor transmission rates (1.10-1.18 mg/m2.s) and moisture absorption values (2.61-32.13%) depending on the relative humidity compared to other EF-ABPs (1.39-1.83 mg/m2.s and 3.48-51.50%, respectively) that have linear structure with smaller branch size. From these results, it was suggested that the galacturonic acid content, molecular weight, degree of esterification and pectin structure of ABP significantly influenced the properties of EFs. The interaction of highly branched pectin chains was stronger than the linear chains, thus reduced the effect of plasticizer and produced a mechanically stronger EF with better barrier properties. Hence, it was suggested that these EFs could be used as alternative degradable packaging/coating materials.

A full factorial experimental design to study the effect of flavoring agents on the mechanical properties of curcumin chewing gum tablets with high solids content.

Objective: Developing chewing gum tablets (CGTs) with high drug loads is a challenge due to the loss of mastication properties. We postulated that poor mastication properties of such gums could be improved by adjusting the concentration of liquid flavors to serve as plasticizers and consequently increase the flexibility of the elastomer in the gum base. To test this hypothesis, the objective of this work was to evaluate the effects of flavor type and concentration, and storage conditions on the textural properties of CGTs loaded with 20% curcumin (CUR) by weight.Methods: CGTs were made by directly compressing Health in Gum® base with CUR. The resultant CGTs were characterized by single and two bites textural tests to measure their yield strength, post-bite failure rate, and compressibility.Results: Flavor concentration (X2) had a significant impact on the masticatory properties of the chewing gums, which could be ascribed to the plasticizing effect of peppermint oil. Addition of liquid flavors and storage at low temperature (X4) produced CGTs with the desirable properties of low yield strength (Y1) and post-bite structural failure rate (Y2), and high compressibility (Y3). The effect of flavors however was negated at high temperatures, especially when flavored gums were stored for extended time at 50 °C. Flavor type (X1) on the other hand had no effect on the masticatory properties of the chewing gums.Conclusions: This study concluded that it is feasible to formulate CGTs with high solids content without negatively impacting their mechanical properties by controlling the concentration of liquid flavors.

Characterization of bioactive film from pectin incorporated with gamma-aminobutyric acid.

Gamma-aminobutyric acid (GABA) is a nutritious bioactive compound that is also an antioxidant. The effect of GABA contents (5-15%) on pectin film properties were investigated and compared to those obtained by adding 10% glycerol, with pure pectin film as the control. The addition of 5% GABA led to similar film tensile strength and elastic modulus with lower film solubility and water vapor permeability compared with film plasticized with 10% glycerol. Additionally, 5% GABA had higher film flexibility compared with the control film. Moreover, GABA content slightly affected the color and moisture content of pectin films with a high antioxidant activity. Furthermore, thermal properties of film plasticized with GABA supported the changes in mechanical properties of pectin film. Therefore, this small amount of GABA provided a desirable film with functional properties similar to those obtained by using the higher amount of glycerol. Thus, GABA not only acted as an alternative plasticizer but also showed antioxidant activity as a bioactive film.

Mucoadhesive films based on gellan gum/pectin blends as potential platform for buccal drug delivery.

Films of gellan gum:pectin blends were prepared by solvent casting method. Gellan gum:pectin mass ratios were varied (4:1; 1:1; 1:4) at different concentrations (3% or 4%) and glycerol was used as plasticizer (1 or 2%). The films were thin (18-30 µm), translucent, flexible, and homogeneous. The surface pH was suitable for buccal application. All films reached high mechanical resistance and the mucoadhesive ability of them was evidenced. High ratio of gellan gum improved the mechanical resistance and the mucoadhesion of the films as well as the control of drug release rates. The films did not disintegrate in simulate saliva up to 24 h and curcumin release could be sustained up to 12 h. The set of data evidence that the films designed in this work represent a potential platform for buccal drug delivery.

Cellulose nanocrystals-starch nanocomposites produced by extrusion: Structure and behavior in physiological conditions.

Different amounts of cellulose nanocrystals (CNCs) were added to glycerol-plasticized thermoplastic starch (TPS) to obtain bio-based nanocomposites. First, nanocomposites are prepared by extrusion and their structure is studied at different scales using WAXS (Wide Angle X-ray Scattering) and solid-state NMR (Nuclear Magnetic Resonance) for local/crystalline organization, AF4 (Asymmetrical Flow Field-Flow Fractionation) for molecular weight and chain length, and SEM (Scanning Electron Microscopy) for the morphology at a larger scale. Then, relevant mechanical properties and behavior in physiological conditions (swelling, enzymatic degradation) are characterized. The results show that the incorporation of cellulose nanocrystals up to 2.5 wt% causes a mechanical reinforcement as determined by DMTA (Dynamic Mechanical Thermal Analysis) and reduces the swelling and the enzymatic degradation of the materials compared to reference TPS. This could be linked to the formation of starch-cellulose hydrogen and hydroxyl bonds. Conversely, above 5 wt% CNC content nanocrystals seem to aggregate which in turn worsens the behavior in physiological conditions.

Comparative study on properties of starch films obtained from potato, corn and wheat using 1-ethyl-3-methylimidazolium acetate as plasticizer.

Starch films are gaining attention as substitutes of synthetic polymers due to their biodegradability and low cost. Some ionic liquids have been postulated as alternatives to glycerol, one of the best starch plasticizers, due to their great capacity to form hydrogen bonds with starch and hence great ability of preventing starch retrogradation and increasing film stability. In this work, [emim+][Ac-]-plasticized starch films were prepared from potato, corn and wheat starch. The effect of starch molecular structure in terms of granular composition (amylose and phosphate monoester contents) and molecular weight (Mw) on film properties was evaluated. Potato starch films were the most amorphous because of the higher Mw and phosphate monoester content of potato starch, both contributing to a lower rearrangement of the starch chains making the crystallization process difficult. In contrast, corn and wheat starches lead to more crystalline films because of their lower Mw, which may imply higher mobility and crystal growth rate, and lower phosphate monoester content. This more crystalline structure could be the responsible of their better mechanical properties. [emim+][Ac-] can be considered suitable for manufacturing starch films showing corn and wheat starch films similar properties to synthetic low-density polyethylene, but involving a simple and environmentally-friendly process.

Storage behavior of caseinate-based films incorporating maize germ oil bodies.

Composite films based on sodium caseinate, plasticized with glycerol and incorporating oil bodies recovered by applying ultrafiltration on maize germ aqueous extract were stored at 25 °C and relevant humidity 53% and the changes in their physicochemical and mechanical properties were monitored over a storage period of 2 months. The rearrangement of the protein matrix molecules, oil droplet reorganization and movement during ageing was revealed through the generalized 2D correlation FTIR spectra analysis. Both the control and the oil bodies-containing caseinate films showed marked alterations of their mechanical and optical characteristics upon storage, mainly due to water uptake and glycerol or oil bodies movement, as the application of 2D correlation of the FTIR spectra time series revealed. The fact that the films become less transparent and, in addition, lose and then regain their mechanical strength during ageing for 70 days is essential information for the development of edible films and their commercial applications in the food industry.

In vitro characterization of elementary osmotic tablet containing celecoxib.

Oral dosage form has limited control over the release of drug from dosage form, hence effective plasma level concentration do not achieve at site of action. Such unusual pattern of dosing results in inappropriate or erratic blood plasma concentrations. The absorption of drug from conventional dosage form depends on factors such as-Physio-chemical properties of the drug, presence of excipient, physiological factors such as presence or absence of food, PH of the gastrointestinal tract etc. Present study highlights osmotically driven oral drug delivery system (tablet) containing celecoxib as an active ingredient. Patients with long term treatment of NSAID (e.g. Arthritis) and suffering from various gastrointestinal side effect will be benefited from such a dosage form. Majority of controlled release dosage forms available in market are generally matrix-based, their principal drug release mechanism was based on drug diffusion through the matrix. Such mechanism is changed by-the pH, presence of food, in the gastrointestinal tract. Body's physiological factors (G.I. motility) also contribute their role in unpredictable absorption. All these factors also affect the release of celecoxib from conventional oral dosage form. Osmotic systems utilize the principle of osmosis as delivery force to release the drug from the dosage form, and the release rate has no effect of the body's pH and other physiological factors, also the various side effects due to long term therapy of NSAIDs are reduced. Batch 6 coated with semipermeable membrane give the maximum of 90.28% release from elementary osmotic tablet in control manner up to 8 hours and following zero order release, other batches e.g. 4and 8 coated with microporous membrane follow first order release.

Synthesis of cobalt-based magnetic nanoporous carbon core-shell molecularly imprinted polymers for the solid-phase extraction of phthalate plasticizers in edible oil.

In this work, cobalt magnetic nanoporous carbon (Co-MNPC) is employed as an alternative to intensively used Fe3O4 cores for the preparation of magnetic molecularly imprinted polymers (Co-MNPC@MIPs) for the first time. Co-MNPC was prepared by one-step carbonization of Zeolitic Imidazolate Framework-67 (ZIF-67). Compared with the traditional Fe3O4 core, Co-MNPC showed a high specific surface area and large pore volumes. The prepared adsorbents, which could be rapidly collected from a matrix by external magnetic field, were applied for solid-phase extraction of phthalate plasticizers in edible oil. Several requisite extraction parameters were optimized to achieve desired extraction performance. Under the optimum extraction conditions, Co-MNPC@MIPs displayed better performance than commercialized columns. An analysis method based on Co-MNPC@MIPs coupled with gas chromatography (GC) was established. The linear range was 1-150 µg mL-1, and the detection limit range was 0.010-0.025 µg mL-1. The spiked recovery rate of the five phthalate plasticizers was 81.6-102.2%, with a relative standard deviation of 3.25-12.02%. Finally, the proposed method showed good feasibility for phthalate plasticizer extraction from edible oil.

In vitro evaluation of di(2-ethylhexyl)terephthalate-plasticized polyvinyl chloride blood bags for red blood cell storage in AS-1 and PAGGSM additive solutions.

BACKGROUND: Di(2-ethylhexyl)phthalate (DEHP) makes polyvinyl chloride flexible for use in blood bags and stabilizes the red blood cell (RBC) membrane preventing excessive hemolysis. DEHP migrates into the blood product and rodent studies have suggested that DEHP exposure may be associated with adverse health effects albeit at high dosages. Although structurally and functionally similar to DEHP, di(2-ethylhexyl)terephthalate (DEHT; or Eastman 168 SG [Eastman Chemical Company]) is metabolically distinct with a comprehensive and benign toxicology profile. This study evaluated RBC stability in DEHT-plasticized bags with AS-1 and PAGGSM compared to conventional DEHP-plasticized bags with AS-1. STUDY DESIGN AND METHODS: Thirty-six whole blood units were collected into CPD solution, leukoreduced, centrifuged, and divided into RBCs and plasma. To limit donor-related variability, three ABO-identical RBCs were mixed together and then divided equally and stored among the three different plasticizer and additive solution combinations. RBCs from 12 trios were analyzed for a standard panel of in vitro variables on Day 0 and after storage. RESULTS: No individual bag on Day 42 exceeded the US 1.0% hemolysis criteria. While hemolysis during storage was higher in the DEHT bags, the PAGGSM RBCs were close to the control RBCs (0.38% vs. 0.32%, respectively). ATP retention was higher than 70% and potassium levels were similar regardless of plasticizer. Additional RBC variables exhibited some significant differences but were not viewed as clinically important. CONCLUSION: DEHT/PAGGSM provides similar hemolysis protection to that of DEHP/AS-1. Although hemolysis values with DEHT and AS-1 are higher than that of DEHP, DEHT is a potential DEHP alternative.

Effect of Presence and Concentration of Plasticizers, Vegetable Oils, and Surfactants on the Properties of Sodium-Alginate-Based Edible Coatings.

Achieving high quality of a coated food product is mostly dependent on the characteristics of the food material to be coated, the properties of the components in the coating solution, and the obtained coating material. In the present study, usability and effectiveness of various components as well as their concentrations were assessed to produce an effective coating material. For this purpose, different concentrations of gelling agent (sodium alginate 0-3.5%, w/w), plasticizers (glycerol and sorbitol (0-20%, w/w), surfactants (tween 40, tween 80, span 60, span 80, lecithin (0-5%, w/w), and vegetable oils (sunflower oil, olive oil, rapeseed oil (0-5%, w/w) were used to prepare edible coating solutions. Formulations were built gradually, and characteristics of coatings were evaluated by analyzing surface tension values and its polar and dispersive components, emulsion droplet size, and optical appearance in microscopic scale. The results obtained showed that 1.25% sodium alginate, 2% glycerol, 0.2% sunflower oil, 1% span 80, and 0.2% tween 40 or tween 80 can be used in formulation to obtain an effective coating for hydrophobic food surfaces. Three formulations were designed, and their stability (emulsion droplet size, optical characteristics, and creaming index) and wettability tests on strawberry showed that they could be successfully used in coating applications.

Enhancement of Moisture Protective Properties and Stability of Pectin through Formation of a Composite Film: Effects of Shellac and Plasticizer.

The aim of this investigation was to develop the high moisture protective ability and stable pectin through the design of composite films based on varying shellac concentrations. A film casting method was applied to prepare a free film. The moisture protective properties and mechanical properties were investigated. The findings was the composite films exhibited the reductions in the hydrophilicity, water vapor permeability, and the moisture content compared with pectin films. The single and composite films were then study for their stability at 40 °C and 75% RH for 90 d. Among the concentrations of shellac, 50% (w/w) could improve stability in terms of moisture protection after 90 d of storage, whereas lower concentrations of shellac (10% to 40%) could not achieve this. However, the higher shellac content also contributed to weaker mechanical properties. The mechanical improvement and stability of composite films with the incorporation of plasticizers were further investigated. Polyethylene glycol 400 and diethyl phthalate at a concentration of 10% were used. The results indicated that both plasticizers could enhance the mechanical characteristics and had a slight effect on moisture protection. The stability of pectin in terms of moisture protective properties could, therefore, be modified through the fabrication of composite films with hydrophobic polymers, that is, shellac and the addition of proper plasticizers to enhance mechanical properties, which could offer wide applications for edible film in food, agro, and pharmaceutical industries. PRACTICAL APPLICATION: The composite film with 50% shellac could improve moisture protective properties of pectin film. Adding a plasticizer could build up the higher mechanical characteristics of composite film. Stability of pectin could be modified by fabrication of composite films with proper content of shellac and plasticizer.