Specific migration of Bisphenol-A Diglycidyl Ether (BADGE) and its derivatives in four different temperatures in epoxy lacquer

      Migration of compounds from packaging materials is one of the most important aspects of food safety. Epoxy resins have been in inner coatings of food cans since the 1960s. These resins can be produced from Bisphenol-A Diglycidyl Ether (BADGE) that is also utilized as a starter. Migration of potentially toxic compounds in epoxy resins used for commercial cans is a very important food safety issue. Residual BADGE from epoxy coating can be hydrolyzed and chlorohydrolysed into two degradation products, which correspond to its first and second hydrolysis and chlorohydrolyse products. Specific migration of these compounds was evaluated in two water-based food stimulants: %3 acetic acid and %15 ethanol at various temperatures (-6, 5, 25 and 40 ̊C) during 10 days. Solid Phase Extraction (SPE) was used to fortify analysts. A flourimetric-detection RP-HPLC was applied to separation and quantification of BADGE, its hydrolysis and chlorohydroxy derivatives. The EU has adjusted the specific migration limit of these compounds in food due to migration from can coatings. Higher levels of migration were found in 15% ethanol than 3% acetic acid. The results illustrated that decreasing of temperature up to –6 ̊C was increased migration. The highest concentration was observed in BADGE.H2O up to 0.9 mg/Kg. Migration of these compounds takes place in food stimulants; the amounts were lower than exceeding EU limits

Oxygen-barrier films based on low-density polyethylene/ ethylene vinyl alcohol/ polyethylene-grafted maleic anhydride compatibilizer

In this research, high oxygen-barrier films were organized based on low-density polyethylene (LDPE)/ ethylene vinyl alcohol (EVOH)/ polyethylene-grafted maleic anhydride (LDPE-g-MA) compatibilizer. The effects of 10–30 wt. % EVOH and 0–10 wt. % LDPE-g-MA loadings on the properties of final films were evaluated. The morphology of specimens was observed by using scanning electron microscopy (SEM). Oxygen transfer rate (OTR) results revealed that the addition of EVOH up to 30 wt. % to neat LDPE could significantly decrease oxygen permeability. The LDPE-g-MA which increased the permeability needed to be fine-tuned its amount based on the EVOH loading in different samples. The experimental results revealed that the addition of 30 wt. % EVOH to the LDPE matrix without adding LDPE-g-MA gave the best oxygen barrier properties. Elastic modulus and tensile strength increased with incorporation of EVOH and LDPE-g-MA into the polyethylene matrix. On the other hand, elongation-at-break decreased with the addition of EVOH and increased with the introduction of compatibilizer to the samples. Incorporation of EVOH and LDPE-g-MA into the LDPE matrix and increasing their amounts led to higher storage modulus and zero shear rate viscosity, but lowered the frequency value at the intersection point of storage modulus (G') and loss modulus (G''). The only exception was that in the samples without compatibilizer, the increase in the EVOH content resulted in a lower zero shear rate viscosity and a higher frequency value at the intersection point of G' and G''

Mechanical Properties and Biodegradability of Polypropylene/Starch Reinforced Nanoclay Blends

Polypropylene/starch nanocomposites compatibilized with PP-g-MA or EVA, with values 0, 3 and 5 wt% of modified clay (Cloisite 30B) were prepared by melt intercalation technique and the mechanical properties, morphology and degradation of nanocomposites were investigated. Tensile test results showed that in the presence of 5 wt% nanoclay, values of tensile strength, elastic modulus and elongation-at-break are 15.5 MPa, 10.2 MPa and 4.2% for PP-g-MA compatibilized blends and 10.0 MPa, 7.0 MPa and 19.4% for EVA compatibilized blends, respectively. Also, the presence of 5 wt% nanoclay increased 9.1 % of tensile strength; 70 % of elastic modulus and decreased 49% of elongation-at-break for PP-g-MA compatibilized blends and increased 40.8% of tensile strength; 27.3% of elastic modulus and 49% of elongation-at-break for EVA compatibilized blends. The reason for these properties improvement could be proper dispersion and physical network consisting of silicate layers in the polymer matrix. SAXS patterns and TEM images confirmed that the prepared nanocomposites were exfoliated. SEM microscopic images show droplet morphology that is indicative of incompatibility of two polymers. Oxidative degradation of samples exposed to UV light was studied using FTIR spectroscopy. The weight loss percentage of MA-5, EVA-3 and EVA-5 specimens after 120 days of exposure in activated sludge resulted in 20.7, 28.4 and 37.9%, respectively. These results indicate that biodegradation of EVA compatibilized blends is much higher with increasing nanoclay which has improved the biodegradablility of the blends

Evaluation of Physical, Mechanical and Antibacterial Properties of Pinto Bean Starch-Polyvinyl Alcohol Biodegradable Films Reinforced with Cinnamon Essential Oil

In the present study, various blended films from polyvinyl alcohol (PVA) and pinto bean starch (PBS) were prepared and the selected film was used to fabricate an antimicrobial packaging film. Different essential oils (EOs) were also exposed to minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests to find the most efficient EO against a range of microorganisms. From the primary studies, the PVA:PBS (80:20) and cinnamon essential oil (CEO) were chosen. Afterward, the blend composite film reinforced by 1, 2, and 3% CEO and several, physical, mechanical, structural, and antimicrobial attributes were scrutinized. The results showed a significant modification of the barrier and mechanical properties of the selected blended films as a result of CEO addition. Scanning electron micrographs confirmed the incorporation and distribution of CEO within the film matrix. The X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra indicated the interaction of CEO and the PVA-PBS composite. The antibacterial of the tested bacteria showed a significant increase by increasing the CEO concentration within the control film. CEO-loaded films were more effective in controlling Gram-positive bacteria compared to Gram-negative bacteria. It can be concluded that PVA-PBS-CEO films are promising candidates to produce biodegradable functional films for food and biomedical applications

Films Based on Poly(lactic acid) Biopolymer: Effect of Clay and Cellulosic Nanoparticles on their Physical, Mechanical and Structural Properties

Physical, mechanical and structural properties of poly(lactic acid) (PLA)-basedfilms containing different amounts of nanoclay and cellulose prepared bysolvent casting method were examined. Physical properties including thickness,transparency and color did not change significantly with addition of nanoparticles to the polymer matrix. X-Ray diffraction (XRD) patterns showed that pure PLA has a semi-crystalline structure and addition of nanoclay into this polymer would produce more regular structure which results in improved crystallization. It also showed that the peak is shifted to lower degrees, with greater interlayer distance of nanoclay giving an intercalated structure. Because of the nature and particle size of the MCC, it did not interact sufficiently with the polymer. Tensile strength, elastic modulus andelongation-at-break of neat PLA were 27.44 MPa, 1.84 GPa and 24.53% which with the addition of 7% of nanoclay, was changed to 40.34, 2.62 and 10.36°C, respectively. As the results of XRD, MCC were indications of no significant effect on mechanical properties, AFM images were used to evaluate the surface morphology and roughness of PLA films. Neat PLA had smoother surfaces and a lower roughness parameter (Sa). This study indicates that PLA has acceptable properties which could be used forpackaging and other applications

Properties and application of multifunctional composite polypropylene-based films incorporating a combination of BHT, BHA and sorbic acid in extending donut shelf-life

To extend the shelf-life of packaged donut without the addition of preservative, polypropylene-based active composite films loaded with a combination of sorbic acid, BHA and BHT were prepared by the extrusion moulding method: T1 (Control-pure PP-film), T2 (PP-BHT1%-SA2%), T3 (PP-BHA3%-SA2%) and T4 (PP-BHT1%-BHA1%-SA2%). The incorporation of active additives enhanced water vapour permeability (WVP) and increased oxygen permeability of films. Active films had higher antioxidant activity than pure PP in the order T4 > T2 > T3 (89.11, 83.40 and 79.16%). In vitro examinations demonstrated a significant antibacterial effect on Escherichia coli and S. aureus growth. Overall migration was not significantly different for watery food simulants, while in acidic and fatty foods increased it significantly. The effect of the active films on the fried and packaged donut samples showed significantly higher moisture contents and peroxide values, while acidity was lower. T2 film is proposed due to the preservation of the intrinsic properties of the film, increasing the storage period up to 25 to 50 days

Evaluation of the photocatalytic antimicrobial effects of a TiO 2 nanocomposite food packaging film by in vitro and in vivo tests

The ability to inactivate Pseudomonas spp. and Rhodotorula mucilaginosa by a photocatalyst thin film, obtained via a combination of anatase and rutile titanium dioxide incorporation into a low density polyethylene (LDPE) polymeric matrix by a melt blending method, was addressed in this study. The number of surviving cell of the Pseudomonas spp. was decreased by 4 log CFU/ml and 1.35 log CFU/ml after 3 h of UVA illumination on TiO2 nanocomposite thin film and LDPE thin film, respectively. The number of cells of R. mucilaginosa decreased by 2 log CFU/ml and 0.64 log CFU/ml on TiO2 nanocomposite thin film and LDPE thin film, respectively. In an in vivo test carried out on fresh pears packaged in TiO2 nanocomposite film and stored under illumination by a fluorescent light lamp at 5 °C for 17 days, the number of mesophilic bacteria and yeast cells decreased significantly compared to samples stored in LDPE film. The greatest effects were recorded by combining UVA illumination and active film. It was also proven that the photocatalyst thin film prepared by extrusion could be effectively used in fruit packaging applications