scholarly journals Polyethylene Migration from Food Packaging on Cheese Detected by Raman and Infrared (ATR/FT-IR) Spectroscopy

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3872
Author(s):  
Klytaimnistra Katsara ◽  
George Kenanakis ◽  
Zacharias Viskadourakis ◽  
Vassilis M. Papadakis
Keyword(s):  
Vibrational Spectroscopy ◽  
Food Packaging ◽  
Time Frame ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Ft Ir ◽  
Comparative Results ◽  
Short Time ◽  
And Storage ◽  
Ft Ir Spectroscopy

For multiple years, food packaging migration has been a major concern in food and health sciences. Plastics, such as polyethylene, are continuously utilized in food packaging for preservation and easy handling purposes during transportation and storage. In this work, three types of cheese, Edam, Kefalotyri and Parmesan, of different hardness were studied under two complementary vibrational spectroscopy methods, ATR-FTIR and Raman spectroscopy, to determine the migration of low-density polyethylene from plastic packaging to the surface of cheese samples. The experimental duration of this study was set to 28 days due to the degradation time of the selected cheese samples, which is clearly visible after 1 month in refrigerated conditions at 4 °C. Raman and ATR-FTIR measurements were performed at a 4–3–4–3 day pattern to obtain comparative results. Initially, consistency/repeatability measurement tests were performed on Day0 for each sample of all cheese specimens to understand if there is any overlap between the characteristic Raman and ATR-FTIR peaks of the cheese with the ones from the low-density polyethylene package. We provide evidence that on Day14, peaks of low-density polyethylene appeared due to polymeric migration in all three cheese types we tested. In all cheese samples, microbial outgrowth started to develop after Day21, as observed visually and under the bright-field microscope, causing peak reverse. Food packaging migration was validated using two different approaches of vibrational spectroscopy (Raman and FT-IR), revealing that cheese needs to be consumed within a short time frame in refrigerated conditions at 4 °C.

scholarly journals Low-Density Polyethylene Films Carrying ferula asafoetida Extract for Active Food Packaging: Thermal, Mechanical, Optical, Barrier, and Antifungal Properties

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Razieh Niazmand ◽  
Bibi Marzieh Razavizadeh ◽  
Farzaneh Sabbagh
Keyword(s):  
Polymer Matrix ◽  
Food Packaging ◽  
Barrier Properties ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Optical Barrier ◽  
Leaf Extracts ◽  
Polyethylene Films ◽  
Active Food Packaging ◽  
Ferula Asafoetida

The physical, thermal, mechanical, optical, microstructural, and barrier properties of low-density polyethylene films (LDPE) containing ferula asafoetida leaf and gum extracts were investigated. Results showed a reduction in elasticity and tensile strength with increasing extract concentration in the polymer matrix. The melting temperature and enthalpy increased with increasing concentration of extracts. The films containing extracts had lower L∗ and a∗ and higher b∗ indices. The films containing leaf extract had more barrier potential to UV than the gum extracts. The oxygen permeability in films containing 5% of leaf and gum extracts increased by 2.3 and 2.1 times, respectively. The morphology of the active films was similar to bubble swollen islands, which was more pronounced at higher concentrations of gum and leaf extracts. FTIR results confirmed some chemical interactions of ferula extracts with the polymer matrix. At the end of day 14th, the growth rate of Aspergillus niger and Saccharomyces cerevisea in the presence of the PE-Gum-5 reduced more than PE-Leaf-5 (3.7 and 2.4 logarithmic cycles, respectively) compared to the first day. Our findings showed that active LDPE films have desire thermo-mechanical and barrier properties for food packaging.

Immobilization of urease in poly(1-vinyl imidazole)/poly(acrylic acid) network

2010 ◽  
Vol 64 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Mehmet Şenel ◽  
Agah Coşkun ◽  
M. Fatih Abasıyanık ◽  
Ayhan Bozkurt
Keyword(s):  
Acrylic Acid ◽  
Enzyme Immobilization ◽  
Storage Stability ◽  
Polymer Network ◽  
Ft Ir ◽  
Basic Characteristics ◽  
And Storage ◽  
Menten Constant ◽  
Ft Ir Spectroscopy ◽  
Poly Acrylic Acid

AbstractIn this study, urease was immobilized in a polymer network obtained by complexation of poly(1-vinyl imidazole) (PVI) with poly(acrylic acid) (PAA). Preparation of the polymer network was monitored by FT-IR spectroscopy. Scanning electron microscopy (SEM) revealed that enzyme immobilization had a strong effect on film morphology. Proton conductivity of the PVI/PAA network was measured via impedance spectroscopy under humidified conditions. Values of the Michaelis-Menten constant (K M) for immobilized urease were higher than for the free enzyme, indicating a decreased affinity of the enzyme to its substrate. The basic characteristics (pHopt, pHstability, T opt, T stability, reusability, and storage stability) of immobilized urease were determined. The results show that the PAA/PVI polymer network is suitable for enzyme immobilization.

Effect of UV Treatment on Optical Properties of Low-Density Polyethylene Films Doped with Eu(TTA)3phen Complex

2014 ◽  
Vol 895 ◽  
pp. 155-161
Author(s):  
M.I. Khairuldin ◽  
N.M.A. Aziz ◽  
N.M. Nashaain ◽  
S. Wedianti ◽  
I. Farehah ◽  
...  
Keyword(s):  
Optical Properties ◽  
Emission Spectra ◽  
Low Density Polyethylene ◽  
Rare Earth Complex ◽  
Low Density ◽  
Uv Treatment ◽  
Uv Spectrum ◽  
Light Manipulation ◽  
Emission Transition ◽  
Ft Ir

Low-Density Polyethylene (LDPE) films doped with Eu (TTA)3phen complex (TTA=2-thenoyltrifluoroacetone, phen=1,10-phenanthroline) were fabricated by hot-blowing technique for thickness of 100 μm. The films were doped with 0.1 % of Eu (TTA)3phen to the total weight of LDPE and exposed to UV irradiation from deuterium lamp for 5, 10, 20, 40 and 60 hours to investigate the effect of its optical properties. The films were characterized by Spectrofluorometer, UV/VIS Spectrophotometer and FT-IR Spectrometer to measure their emission spectra, lifetimes, transmission transparency and chemical bonding. Photoluminescence of the room-temperature Eu (TTA)3phen doped films consist of typical Eu3+emission transition lines with hypersensitive5D07F2emission band at 610 nm. After 20 hours UV treatment, the peak intensity dropped by 90 % and shortened the luminescent lifetimes from 0.654 ms to 0.305 ms. Longer UV treatment also has accelerated degradation in doped LDPE films shown by significant reducing in absorption peak of FTIR at 3395, 3186 and 1645 cm-1. The results would provide a mechanism to improve the lifetime of the LDPE by utilizing the light-manipulation property of Eu (TTA)3phen complex to absorb UV spectrum and covert into red emission.Keywords: LDPE, rare-earth complex, photoluminescence

scholarly journals Protective Low-Density Polyethylene Residues from Prepreg for the Development of New Nanocomposites with Montmorillonite: Recycling and Characterization

Recycling ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 45
Author(s):  
Pamela Rodrigues Passos Severino ◽  
Thaís Larissa do Amaral Montanheiro ◽  
Orestes Ferro ◽  
Fábio Roberto Passador ◽  
Larissa Stieven Montagna
Keyword(s):  
Carbon Fiber ◽  
Extrusion Process ◽  
Morphological Properties ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Primary Role ◽  
Protective Films ◽  
And Storage ◽  
Compatibilizer Agent ◽  
The Ideal

A sustainable alternative to the destination of polyethylene (PE) residue from the prepreg package was established. This work intends to develop nanocomposites for packaging containing neat low-density polyethylene (LDPE), a compatibilizer agent (maleic anhydride grafted-LDPE, LDPE-g-MA), recycled LDPE obtained from the protective films of prepreg (rLDPE) and montmorillonite (MMT). The rLDPE, from the prepreg shield, has a primary role during the transport and storage of prepreg, which can be composed of epoxy resin and carbon fiber or glass fiber. However, this rLDPE is withdrawn and discarded, besides, it is estimated that tons of this material are discarded monthly by the company Alltec Materiais Compostos Ltd. (São José dos Campos-SP, Brazil). Due to several factors, including the lack of technology for recycling, the majority of this material is incinerated. In this context, this work presents a technical and ecologically viable alternative for the use of this discarded material. Nanocomposites of LDPE/rLDPE blends and montmorillonite (MMT) with different contents (0.0, 1.0, and 3.0 wt%) and with the addition of compatibilizer agent (LDPE-g-MA) were prepared by extrusion process. Test specimens were obtained by hot pressing in a hydropneumatic press followed by die-cutting. The nanocomposites produced using rLDPE presented good mechanical, thermal, and morphological properties, being the ideal concentration of 1 wt% MMT. Thus, the results obtained confirmed the viability of recycling LDPE from the prepreg package which contributes to the reduction of waste and the use of this material in technological applications.

On the durability of low-density polyethylene nanocomposites

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Jitendra K. Pandey ◽  
Raj Pal Singh
Keyword(s):  
Ir Spectroscopy ◽  
Morphological Changes ◽  
Diffusion Path ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Neat Polymer ◽  
The Matrix ◽  
Ft Ir ◽  
The Stability ◽  
Artificial Uv

Abstract Low-density polyethylene (PE) containing nano-particulate clay was prepared after functionalization with maleic anhydride (MA) by reactive grafting in the presence of peroxide followed by blending of maleated PE with neat polymer in different concentrations. Four classes of composites were obtained: (i) exfoliated, (ii) intercalated, (iii) microcomposites, and (iv) intermediate of intercalated and microcomposites, as evidenced by wide-angle X-ray diffraction. All samples were kept for artificial UV irradiation (λ ≥ 290 nm) and for composting to study their photo- and bio-durability. Fourier-transform IR spectroscopy (FT-IR) and scanning electron microscopy were used to monitor the functional group and morphological changes, respectively, whereas biodurability was evaluated by measuring the weight loss. MA functionalization and nature of composites have detrimental effects on the overall durability of composites. Nanocomposites showed higher resistance than microcomposites during initial weathering and composting with a long induction period. The stability of nanocomposites decreases with time and overall durability was worse than of pristine polymer in both environments. It was concluded that the initial protection is due to the filler-generated long diffusion path, which decreases the oxygen diffusion through the matrix. The bio-durability of composites decreased with oxo-degradation. Biodegradation of PE nanocomposites during composting follows the mechanism described by Albertsson et al. as evidenced by FT-IR spectroscopy.

Effects of low density polyethylene liners and high-density polyethylene wraps on quality, decay and storage life of lemon and tangor fruits

1985 ◽  
Vol 25 (3) ◽  
pp. 718 ◽  
Author(s):  
PJ Sharkey ◽  
CR Little ◽  
IR Thornton
Keyword(s):  
High Density Polyethylene ◽  
Citrus Sinensis ◽  
Storage Life ◽  
High Density ◽  
Low Density Polyethylene ◽  
Citrus Limon ◽  
Citrus Reticulata ◽  
Low Density ◽  
Cool Storage ◽  
And Storage

Winter-maturing Lisbon lemons (Citrus limon (L.) Burm.f.) and Ellendale tangors (Citrus reticulata x Citrus sinensis (L.) Osbeck) which had been dipped in fungicides and waxed, developed less than 10% rot but remained fresh for only 2-3 months in cool-storage at 10�C and 80-90% RH. High-density polyethylene (HDPE) wraps delayed loss of firmness and peel coloration of tangors and lemons for 5 and 8 months respectively, in cool-storage, but both citrus developed unacceptable levels of rotting within 4 months of harvest. Perforated low-density polyethylene liners were less effective than HDPE wraps for preserving fruit condition but they extended the storage life of lemons until early January (6 months) without incurring levels of decay greater than 10%. However, tangors cool-stored in liners became unsaleable after only 3-4 months owing to loss of acidity and flavour.

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