Research of the polyethylene packaging layer structure change in contact with a food product at exposure to ultraviolet radiation

The sanitary and hygienic safety of modern packaging is determined by the layer of packaging material in direct contact with the food product. This layer in most cases is a synthetic polymer of the polyolefin class — low density polyethylene. This material is used as a stand-alone packaging and in multilayer and combined packaging materials. During thermal and photooxidation, compounds can form in it that negatively affect the safety of the package, which can migrate into the product. Food technologies use methods of disinfecting packaging materials and packaging before filling or bottling products. These methods include ultraviolet irradiation of the surface, which has a bactericidal effect. Using spectral methods of analysis, researches have been carried out on changes in the polyethylene layers structure in the film’s composition, multilayer films and combined packaging materials when exposed to pulsed ultraviolet radiation in a wide spectral range (irradiation with a pulsed xenon lamp). Deformations of polyethylene macromolecules chemical bonds on the surface and boundary layers under the influence of pulsed UV-irradiation have been revealed. The IR spectra of ATR (Attenuated Total Reflection) were obtained, the analysis of which showed that the monofilm is subject to the greatest destructive effect, as evidenced by the appearance of characteristic absorption bands responsible for the formation of aldehyde, ketone groups, as well as for the polymer chain termination. It is shown that the use of food soot in the composition of multilayer packaging films blocks their photo destruction. Upon irradiation of a combined material based on cardboard intended for bottling milk, an absorption band was found in the spectra, which is responsible for the onset of the destruction process with the formation of aldehyde and carboxylate groups with the formation of aldehyde and carboxylate groups.Comparison of changes in structure in three different packaging objects containing a polyethylene layer shows the feasibility and necessity of using combined and multilayer materials for food products packaging, in which, even under extreme UV-irradiation, there are practically no photo destruction processes, which is confirmed by spectral researches.

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Organic Matter and Mineral Composition of Silicate Soils: FTIR Comparison Study by Photoacoustic, Diffuse Reflectance, and Attenuated Total Reflection Modalities

Agronomy ◽

10.3390/agronomy11091879 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1879

Author(s):

Dmitry S. Volkov ◽

Olga B. Rogova ◽

Mikhail A. Proskurnin

Keyword(s):

Organic Matter ◽

Mineral Composition ◽

Diffuse Reflectance ◽

Total Reflection ◽

Attenuated Total Reflection ◽

Absorption Bands ◽

Data Treatment ◽

Carboxylate Groups ◽

The Matrix ◽

Primary Water

This study aims to compare photoacoustic (FTIR–PAS), diffuse reflectance (DRIFT), and attenuated total reflection (ATR) FTIR modalities in the wide wavenumber range from NIR (7500 cm−1) to FIR (150 cm−1) for the same silicate soil samples under the same conditions. The possibilities of non-destructive rapid qualitative analysis of soils by these modalities without comprehensive data treatment were compared. The assignment of more than 100 bands for the chernozem and sod-podzolic as common types of silicate types of soil was made. The following groups of bands of organic matter and inorganic matrix were reliably found in spectra of all or at least two modalities: 3690–3680 cm−1 (hydrogen-bonded SiO–H…H2O stretch, not ATR), 2930–2910 cm−1 and 2860–2850 cm−1 (methylene stretch), 1390–1380 cm−1, (symmetric stretch carboxylate, DRIFT and FTIR–PAS); 2000–1990 cm−1, 1885 cm−1, and 1790–1783 cm−1 (SiO2 overtones, DRIFT and FTIR–PAS), 1163–1153 cm−1, SiO2 lattice (not FTIR–PAS), 1037 cm−1 (Si–O or Al–O stretch), 796 cm−1 (lattice symmetrical Si–O–Si stretch); 697 cm−1, SiO2; and 256 cm−1 (not FTIR–PAS). Amide I, II, and III bands appear in DRIFT and FTIR–PAS spectra while not in ATR. Except for methylene and carboxylate groups, CH vibrations (3100–2900 cm−1) are not seen in ATR. Bands at 1640–1630 cm−1, 1620–1610 cm−1, 1600–1598 cm−1 (primary water bands and probably carboxylate) appear in the spectra of all three modalities but are unresolved and require data treatment. It is preferable to use all three modalities to characterize both soil organic matter and mineral composition. DRIFT provides the maximum number of bands in all three modalities and should be selected as a primary technique in the NIR and 4000–2000 cm−1 regions for hydrogen-bonding bands, CHX groups, and the silicate matrix. ATR–FTIR complements DRIFT and provides a good sensitivity for soil water and the matrix in 2000–400 cm−1. FTIR–PAS in 4000–1500 cm−1 reveals more bands than DRIFT and shows the highest sensitivity for absorption bands that do not appear in DRIFT or ATR-IR spectra. Thus, FTIR–PAS is expedient for supporting either DRIFT or ATR–FTIR. This modality comparison can be a basis for methodological support of IR spectroscopy of soils and similar organomineral complexes.

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Effect of Water Leaching on Photodegraded Scots Pine and Spruce Timbers Monitored by FTIR Spectroscopy

Forests ◽

10.3390/f12070833 ◽

2021 ◽

Vol 12 (7) ◽

pp. 833

Author(s):

Edina Preklet ◽

László Tolvaj ◽

Eszter Visi-Rajczi ◽

Tamás Hofmann

Keyword(s):

Ftir Spectroscopy ◽

Scots Pine ◽

Uv Irradiation ◽

Chemical Elements ◽

Uv Light ◽

Carbonyl Groups ◽

Water Leaching ◽

Absorption Bands ◽

Chemical Changes ◽

Absorption Increase

The goal of this research was the systematic study and comparison of the divided individual effects of UV light irradiation and water leaching during artificial weathering. Spruce (Picea abies Karst.) and Scots pine (Pinus sylvestris L.) samples were irradiated by ultraviolet (UV) light. Another sequence of samples was treated with the combination of UV irradiation and water leaching. The total extent of UV treatment was 20 days for both series of samples. Time relation of UV irradiation and water leaching was 2:1. The chemical changes were observed by FTIR spectroscopy. The difference spectrum was used for determination of the chemical changes. Degradation of lignin was greater for the leached samples than for the pure UV treated samples. Scots pine suffered greater lignin degradation than spruce, and produced higher absorption increase on the absorption region of unconjugated carbonyls. The unconjugated carbonyl groups were the most responsive chemical elements to leaching. Spruce was more susceptible to leaching of unconjugated carbonyl groups than Scots pine. Two absorption bands of unconjugated carbonyl groups at 1706 and 1764 cm−1 wavenumbers were produced by photodegradation. The absorption band at 1764 cm−1 was more sensitive to water leaching than the band at 1706 cm−1.

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Degradation of bacteria mass spectral signals via hydrothermal processing and UV irradiation: relevance to life detection on icy moons

10.5194/epsc2021-518 ◽

2021 ◽

Author(s):

Tara Salter ◽

Hunter Waite ◽

Mark Sephton

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Uv Irradiation ◽

Gas Chromatography Mass Spectrometry ◽

Xenon Lamp ◽

Hydrothermal Processing ◽

Mass Spectral ◽

Icy Moons ◽

Chromatography Mass Spectrometry ◽

Life Detection

The inferred subsurface oceans of the icy moons of Jupiter and Saturn, in particular Europa and Enceladus, may contain conditions suitable for life. Plumes of material have been detected from Enceladus and may also be present on Europa. These plumes could contain molecular signs of habitability that could be detected by mass spectrometers on orbiting spacecrafts, such as the upcoming Europa Clipper mission. However, these molecular markers may have degraded between their production and detection, for example by possible hydrothermalism in the subsurface ocean or by UV irradiation once carried into space by the plume. It is important to look at how the biosignatures degrade under different conditions as degradation processes need to be taken into account when analysing the data from life detection missions. We investigate how these two processes affect the mass spectral signals of terrestrial bacteria. Two cyanobacteria samples, Spirulina and Chlorella, were subjected to hydrothermal processing and UV irradiation. Hydrous pyrolysis was used to simulate hydrothermal degradation. Experiments were carried out for 24 or 72 hours at temperatures between 200 and 300 &#176;C. The pyrolyzed contents were subsequently extracted and analysed with gas chromatography-mass spectrometry (GC-MS). UV irradiation was carried out in a vacuum chamber (10-2 mbar), using a 300 W short arc xenon lamp at UV to near infrared wavelengths (~250 &#8211; 800 nm). After UV irradiation, samples were analysed using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). Our results show that hydrothermal processing of cyanobacteria affects the compound classes in different ways. Carbohydrate and protein components from the cyanobacteria were significantly affected, with phenol and indole derivatives detected. However, some of the biological fingerprint, such as straight-chain even numbered saturated fatty acids from lipid fragments, remain even at the harshest experimental conditions used in our study. This provides confidence that these diagnostic molecules could be used as fingerprints of biological materials on icy moons.

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Food Product Shelf Stability Overview of Sourdough-risen Flatbread

10.47363/jftns/2021(3)123 ◽

2021 ◽

pp. 1-5

Author(s):

Melaku Tafese Awulachew ◽

Keyword(s):

Shelf Life ◽

Food Quality ◽

Total Pressure ◽

Food Product ◽

Food Preservation ◽

Packaging Materials ◽

Quality Loss ◽

Extrinsic Factors ◽

Shelf Stability ◽

Intrinsic And Extrinsic Factors

This paper aims to Provide an overview of food preservation related to the shelf-life and stability of food products including sourdough-risen flatbread (injera). Understanding the properties and composition of injera products enables one for a better option for maintaining food quality at desirable level of properties or nature for their maximum benefits. Food quality loss can be described in terms of as environmental factors which include temperature, relative humidity, light, mechanical stress and total pressure such as compositional factors, concentration of reactive species, microorganism levels, catalysts, reaction inhibitors, pH and water activity, as well. There are a range of points in the food chain where manufacturers can influence the mix of intrinsic and extrinsic factors which affect shelf-life. Advances in processing and packaging materials and techniques have increased the options available for maintaining quality and for improving the shelf-life of foods.

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Chemical Synthesis and Properties of Layered Co1-yNiyO2-δOxides (0≤y≤1)

MRS Proceedings ◽

10.1557/proc-658-gg8.12 ◽

2000 ◽

Vol 658 ◽

Author(s):

A. Manthiram ◽

R. V. Chebiam ◽

F. Prado

Keyword(s):

Layer Structure ◽

Magnetic Data ◽

Chemical Analyses ◽

X Ray Diffraction ◽

Absorption Bands ◽

X Ray ◽

Ni Content ◽

Wet Chemical ◽

Oxide Ions ◽

Structure Layer

ABSTRACTLayered Co1-yNiyO2-δ oxides with 0≤y≤1 have been synthesized by chemically extracting lithium from LiNi1-yCoyO2 with NO2PF6 at ambient temperature. The samples have been characterized by X-ray diffraction, wet-chemical analyses, infrared spectroscopy, and magnetic susceptibility measurements. While NiO2-δ retains the initial O3 (CdCl2 structure) layer structure of LiNiO2, CoO2-δ consists of a mixture of P3 and O1 (CdI2 structure) phases that are formed by a sliding of the oxide ions in the initial O3 structure. CoO2-δ and NiO2-δ have oxygen contents of, respectively, 1.67 and 1.95 and the oxygen content increases with increasing Ni content, y, in Co1-yNiyO2-δ. While CoO2-δ exhibits metallic conductivity as revealed by theabsence of absorption bands in the infrared spectrum, NiO2-δ exhibits semiconducting behavior due to a completely filled t2g band. Magnetic data reveal a transition from antiferromagnetic to ferromagnetic correlations as the Ni content in Co1-yNiyO2-δ increases.

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Application of ATR-FT-MIR for Tracing the Geographical Origin of Honey Produced in the Maltese Islands

Foods ◽

10.3390/foods9060710 ◽

2020 ◽

Vol 9 (6) ◽

pp. 710 ◽

Cited By ~ 2

Author(s):

Jean Paul Formosa ◽

Frederick Lia ◽

David Mifsud ◽

Claude Farrugia

Keyword(s):

Geographical Origin ◽

Food Product ◽

Attenuated Total Reflection ◽

Support Vector ◽

Spectroscopic Techniques ◽

Mir Spectroscopy ◽

Product Models ◽

Vector Machines ◽

Spectral Transformations ◽

Non Local

Maltese honey has been produced, marketed, and sold as an exclusive local gourmet food product for countless years. Yet, thus far, no study has evaluated the individuality of this local food product. The evaluation of the parameters and properties which characterise the provenance and floral source of honey have been the subject of various studies worldwide, owing to the price and potential beneficial properties of this food product. Models analysing the potential of attenuated total reflection mid-infrared (ATR-FT-MIR) spectroscopy in discriminating and classifying local honey from that of foreign origin were investigated using 21 Maltese honey samples and 49 honey samples collected from abroad (Sicily, Greece, Sweden, Italy, France, Estonia and other samples of mixed geographical origin). Through a combination of spectroscopic techniques, spectral transformations, variable selection and partial least squares discriminant analysis (PLS-DA), chemometric models which successfully classified the provenance of local and non-local honey were developed. The results of these models were also corroborated with other classification and pattern recognition techniques, such as linear discriminate analysis (LDA), support vector machines (SVM) and feed-forward artificial neural networks (FF-ANN).

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Structural Study on Fat Crystallization Process Heterogeneously Induced by Graphite Surfaces

Molecules ◽

10.3390/molecules25204786 ◽

2020 ◽

Vol 25 (20) ◽

pp. 4786

Author(s):

Fumitoshi Kaneko ◽

Yoshinori Yamamoto ◽

Shinichi Yoshikawa

Keyword(s):

Sampling Method ◽

Layer Structure ◽

Thermal Fluctuations ◽

Attenuated Total Reflection ◽

Graphite Surface ◽

Fat Crystallization ◽

Organic Crystals ◽

The Novel ◽

Β Phase ◽

Hydrocarbon Chains

Some inorganic and organic crystals have been recently found to promote fat crystallization in thermodynamically stable polymorphs, though they lack long hydrocarbon chains. The novel promoters are talc, carbon nanotube, graphite, theobromine, ellagic acid dihydrate, and terephthalic acid, among which graphite surpasses the others in the promotion effect. To elucidate the mechanism, we investigated the influence of graphite surfaces on the crystallization manner of trilaurin in terms of crystal morphology, molecular orientation, and crystallographic features. Polarized optical microscopy, cryo-scanning electron microscopy, synchrotron X-ray diffractometry, and polarized Fourier-transform infrared spectroscopy combined with the attenuated total reflection sampling method were employed for the analyses. All the results suggested that the carbon hexagonal network plane of graphite surfaces have a high potential to facilitate the clustering of fat molecules against high thermal fluctuations in fat melt, the fat molecules form a layer structure parallel to the graphite surface, and the clusters tend to grow into thin plate crystals of the β phase at the temperatures corresponding to low supercooling. The β′ phase also has a larger chance to grow on the graphite surface as supercooling increases.

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A discussion on infared astronomy - On the chemistry of Jupiter's upper atmosphere

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1969.0008 ◽

1969 ◽

Vol 264 (1150) ◽

pp. 151-151

Keyword(s):

Ultraviolet Radiation ◽

Cross Section ◽

Infrared Radiation ◽

Organic Molecules ◽

General Procedure ◽

Analytical Approximation ◽

Upper Atmosphere ◽

Rapid Rise ◽

Absorption Bands ◽

Jovian Atmosphere

The infrared opacity of Jupiter’s upper atmosphere will be influenced by line blanketing resulting from strong absorption bands of ammonia and organic molecules. In order to calculate these effects eventually, we conduct a first investigation into the ion-molecule chemistry of the upper Jovian atmosphere. Experimental results show that intense ultraviolet radiation reacts with the constituents of the Jovian atmosphere to produce C2H4> ^2^65 a, and higher polymers. The general procedure for calculating both equilibrium and non-equilibrium abundances of these products is formulated and applied to the case of the surface passage of a satellite shadow. A specific example is made of ethylene, for which an analytical approximation gives 10 (to power of 10) molecules in an atmospheric column of 1 cm2 cross-section after a very rapid rise to equilibrium. Such a concentration of ethylene does not substantially affect the infrared radiation in the shadow.

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Detonation Nanodiamonds: A Comparison Study by Photoacoustic, Diffuse Reflectance, and Attenuated Total Reflection FTIR Spectroscopies

Nanomaterials ◽

10.3390/nano10122501 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2501

Author(s):

Dmitry S. Volkov ◽

Petr K. Krivoshein ◽

Mikhail A. Proskurnin

Keyword(s):

Diffuse Reflectance ◽

Depth Profiling ◽

Total Reflection ◽

Attenuated Total Reflection ◽

Comparison Study ◽

Absorption Bands ◽

Full Characterization ◽

Ftir Spectrometry ◽

Out Of Plane

The qualitative analysis of nanodiamonds by FTIR spectrometry as photoacoustic (FTIR–PAS), diffuse-reflectance (DRIFT), and attenuated total reflection (ATR) modalities was evaluated for rapid and nondestructive analysis and comparison of nanodiamonds. The reproducibility and signal-gathering depth of spectra was compared. The assignment of characteristic bands showed that only six groups of bands were present in spectra of all the modalities with appropriate sensitivity: 1760 (C=O stretch, isolated carboxyl groups); 1640–1632 (H–O–H bend, liquid water); 1400–1370 (non-carboxyl C–O–H in-plane bend and CH2 deformation); 1103 (non-carboxyl C–O stretch); 1060 (in-plane C–H bend, non-aromatic hydrocarbons and carbohydrates); 940 cm−1 (out-of-plane carboxyl C–O–H bend). DRIFT provides the maximum number of bands and is capable of measuring hydrogen-bonded bands and CHx groups. ATR provides the good sensitivity for water and C–H/C–C bands in the range 2000–400 cm−1. FTIR–PAS reveals less bands than DRIFT but more intense bands than ATR–FTIR and shows the maximum sensitivity for absorption bands that do not appear in ATR-IR spectra and are expedient for supporting either DRIFT or FTIR–PAS along with depth-profiling. Thus, all three modalities are required for the full characterization of nanodiamonds surface functional groups.

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Fabrication and Properties of Pr3+-Doped Lithium Gadolinium Borate Glasses

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.707.131 ◽

2016 ◽

Vol 707 ◽

pp. 131-134

Author(s):

Kitipun Boonin ◽

Warawut Sa-Ardsin ◽

Jakrapong Kaewkhao

Keyword(s):

Luminescence Intensity ◽

Atmospheric Pressure ◽

Emission Spectra ◽

Xenon Lamp ◽

Borate Glasses ◽

Melt Quenching ◽

Absorption Bands ◽

Color Coordinates ◽

Emission Light

Pr3+-doped Li2O – Gd2O3 – B2O3 glasses (LGBO glass) with the formula 60Li2O:10Gd2O3:(30-x)B2O3:xPrO3 were fabricated using melt quenching technique. The five glass samples with different concentrations of Pr2O3 were prepared under atmospheric pressure. The samples were investigated on their properties: absorption and photoluminescence. All absorption bands are increase with increasing of Pr3+ content. The emission spectra were measured with 446 nm light pumped by xenon lamp. The maximum luminescence intensity was observed at x = 0.50 mol% andthe CIE color coordinates showed the bluish purple emission light for this concentration.

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