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Plastic greenhouses play an important role in vegetable cultivation in China. While evaluations have attributed perfluoroalkyl acid contamination in greenhouse vegetables primarily to irrigation water, the potential contribution from greenhouse plastic films has consistently been overlooked, despite PFAAs' long-standing use as anti-fogging agents. In this study, a comprehensive assessment of PFAA contamination was conducted in greenhouses at the Shouguang vegetable base in China, based on extensive environmental and crop sample collection, followed by analysis using LC-MS/MS. PFAAs are still used in greenhouse plastic film, and their migration to the surface water mist and the air inside the greenhouse was also observed. Elevated levels of PFAA pollution were found near the corner areas of greenhouses with longer service times, leading to further pollution of the soil and nearby vegetables. This is considered as the primary source which may have been caused by PFAAs migrating with condensation from the plastic film and accumulating for decades. However, polluted irrigation water still remains the dominate source of PFAAs in other areas inside the greenhouse. Based on our analysis, we conclude that PFAAs present in plastic films could be the primary contaminant source for vegetables in specific zones. This underscores the urgent need for heightened vigilance towards environmental pollution within agricultural facilities, which currently represent the most prevalent mode of intensive vegetable cultivation in China. [ABSTRACT FROM AUTHOR]

In this research, qualitative characteristics were studied under different post-harvest treatments in Hass and Fuerte cultivars of avocado (Persea americana) fruits. The post-harvest treatments performed in fruits of these cultivars comprised Ethrel application and plastic film (membrane) covering. The measurements of qualitative characteristics were related to color; flesh consistency; measurements of titratable acidity, total soluble solids, percentage of total phenolic contents, and ascorbic peroxidase activity; and the real-time (quantitative) polymerase chain reaction (qPCR) of gene expression and enzyme activities of phenylalanine ammonia-lyase (PAL) and beta-galactosidase (β-gal). The experiments found that the application of plastic film has excellent results in retaining qualitative characteristics and enzyme activities via maintaining firmness in higher levels. The plastic film covering appeared to delay ripening without the use of chemicals and, therefore, it has the potential to extend the duration of the post-harvest life of the avocado fruit. Variations between the two cultivars were found in the measurements of total soluble solids (Fuerte cultivar showed an increase of 22%, whereas Hass cultivar showed an increase of 120% in Brix values) and total phenolic contents (Fuerte cultivar showed a decrease of 16% and Hass cultivar showed an increase of 29%). It is worth noting that PAL's activity increased significantly (over 44%), as compared to other treatments, and β-galactosidase's activity decreased, as compared to other treatments. In conclusion, plastic film covering results in a decrease in the activity of β-galactosidase, as shown by the reaction of hydrolysis (enzyme activity) but also from the expression of the related genes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To address residual plastic film in fields in which mulched drip irrigation technology is applied, a sprayable degradable film (consisting of 1–5% clay, 5–20% humic acid, 0.5–5% crosslinker, and 0.5–5% auxiliary and water) can be used as a superior alternative to the plastic film applied in drip-irrigated fields. A field experiment was conducted in Xinjiang, Northwest China, to test the impacts of five different mulching treatments (SF1, sprayable degradable film applied at 1900 kg ha−1; SF2, sprayable degradable film applied at 1900 kg ha−1; SF3, sprayable degradable film applied at 2500 kg ha−1; PF, plastic film; and NF, no film mulching) on cotton growth and development, yield, and water use efficiency. The results showed that, compared to the NF treatment, sprayable degradable film mulching (SF1, SF2, and SF3) positively impacted the soil hydrothermal environment, promoted root growth, significantly increased plant height and leaf area, and enhanced physiological characteristics, which, in turn, increased yield and water use efficiency by 11.79–15.00% and 21.88–30.21%, respectively. The maximum yield and water use efficiency were observed in the PF treatment, amounting to 5345 kg ha−1 and 1.28 kg m−3, respectively, and they had no significant differences from those in the SF3 treatment. In general, applying moderate amounts of sprayable degradable film at a rate of 2500 kg ha−1 represents an effective agronomic strategy for managing residual film contamination while maintaining stable cotton yields. [ABSTRACT FROM AUTHOR]

Plastic greenhouses play an important role in vegetable cultivation in China. While evaluations have attributed perfluoroalkyl acid contamination in greenhouse vegetables primarily to irrigation water, the potential contribution from greenhouse plastic films has consistently been overlooked, despite PFAAs’ long-standing use as anti-fogging agents. In this study, a comprehensive assessment of PFAA contamination was conducted in greenhouses at the Shouguang vegetable base in China, based on extensive environmental and crop sample collection, followed by analysis using LC-MS/MS. PFAAs are still used in greenhouse plastic film, and their migration to the surface water mist and the air inside the greenhouse was also observed. Elevated levels of PFAA pollution were found near the corner areas of greenhouses with longer service times, leading to further pollution of the soil and nearby vegetables. This is considered as the primary source which may have been caused by PFAAs migrating with condensation from the plastic film and accumulating for decades. However, polluted irrigation water still remains the dominate source of PFAAs in other areas inside the greenhouse. Based on our analysis, we conclude that PFAAs present in plastic films could be the primary contaminant source for vegetables in specific zones. This underscores the urgent need for heightened vigilance towards environmental pollution within agricultural facilities, which currently represent the most prevalent mode of intensive vegetable cultivation in China.

In this study, we investigated the mechanical properties and inner structure of the films of linear low-density polyethylene (LLDPE) It was re-pelletized by a twin-screw extruder equipped with and without a molten-resin reservoir (MRR) with different extrusion conditions. The thin sample films (thickness: 0.1 mm) were prepared by a compression moulding machine and then their mechanical properties and inner structure were analysed by a tensile test machine and XRD, Imaging FT-IR, AFM and RAMAN analyses. From the tensile results, the mechanical properties of re-pelletized pellet films were improved compared to the film made from virgin LLDPE pellets. Besides, from the analysis results, some inner-structural changes were confirmed in films made from re-pelletized pellets by AFM and Raman analyses and they depend on the re-pelletizing process. Our results suggest that the re-pelletizing treatment affected the inner structure of the films, resulting in the improving their mechanical properties.

Featured Application: This work is of particular interest in the design of products widely used in daily life, such as HDPE and LLDPE blend plastic bags. The aim of this study is to analyze how the main process parameters (BUR, TUR, and TR) affect the mechanical properties of this type of product, helping designers to adapt the production to customers' new requirements while maintaining the product properties. All the samples were manufactured on an industrial scale. The results are beneficial so that the highest tensile and impact properties can be obtained through minimal changes in the already mentioned process parameters, thus also reducing the amount of waste due to products manufactured outside the specification limits. Polyethylene plastic bags manufactured via blown film extrusion have different quality specifications depending on their intended use. It is known that the mechanical properties of a film depend on the process parameters established, but little is known concerning how they affect one another, even more so due to the variety of polyethylene materials and processing techniques. This study focuses on establishing a proper correspondence of important mechanical properties like the dart impact, tensile strength at break, and elongation at break with commonly used process parameters like the blow-up ratio, take-up ratio, thickness reduction, and neck height, for a high-density polyethylene hexene copolymer and a linear low-density polyethylene butene copolymer blend film. Because this polyethylene mixture is an anisotropic material, interesting R2 values equal to or higher than 0.90 were found: a BUR with elongation at break and tensile strength at break in the MD and TD, a TUR with elongation at break in the MD and tensile strength at break in the MD and TD, and a TR with elongation at break and tensile strength at break in the MD. Also, a relationship between the dart impact and both the neck height and thickness were found. [ABSTRACT FROM AUTHOR]

The investigation of the issue of extending the period of consumption of fresh napa cabbage with different head weights due to the use of polymer films is relevant. The purpose of the study was to experimentally substantiate measures to extend the consumption of napa cabbage. The products were grown and stored on a farm. Studies with napa cabbage heads were conducted using the laboratory method and the method of mathematical statistics. It is established that napa cabbage loses up to 10% of its mass during storage for 20 days of storage. Individual packaging of heads in stretch film, in comparison with storage in open form, allowed for reducing the natural loss of their mass by half, increasing the storage period to 90 days. Among the hybrids examined, the best keeping properties were identified in a hybrid characterised by a high content of dry and dry soluble substances, vitamin C, and total sugar. When examining the shelf life of napa cabbage, depending on the weight of the head, it is identified that the stretch film extends the duration of storage of heads weighing 350-700 and 750-900 g to 70 days. Natural weight loss reaches 10.8%. Heads weighing more than 900 g with such packaging are stored for 90 days with natural losses of 8.8%. Inserts made of polyethylene film with a thickness of 40 microns extended the storage time of cabbage heads weighing 350-700 g to 80 days with a weight loss of 10.1%. Heads weighing 750-900 and more than 900 g were stored for 90 days with natural mass losses of 10 and 7.8%, respectively. Storage of a mixture of napa cabbage heads of different weights in the stretch film increased the storage period to 80 days, and in polyethylene film – to 90 days with a weight loss of about 10%. These results can be used by researchers in the trade industry to extend the storage period of fruits and vegetables

In semiarid regions of Brazil, water and/or soil salinity is one of the limiting factors for sour passion fruit production. Low rainfall rates combined with edaphic conditions (high concentrations of soluble salts) intensify deleterious effects on plants. Thus, strategies that minimize the effects of salt stress, e.g., grafting with tolerant species and soil mulching, are extremely important to ensure the expansion of irrigated fruit farming in this region. From this perspective, this study aimed to evaluate the effect of grafting and mulching on the quantum yield, ionic relations, and fruit production of sour passion fruit irrigated with moderately saline water. The experiment was conducted under field conditions in split plots, in a 2 × (2 × 2) factorial arrangement to evaluate the combination of low and moderate salinity water (main plot) with the propagation method (seeds and grafting on P. cincinnata) and without and with plastic mulching (subplots), with four replications and three plants per plot. The ionic relations in passion fruit leaves were increased with the use of rootstocks and plastic mulching under irrigation with moderately saline water. The use of mulching increased the yield of photosystem II in sour passion fruit. The passion fruit plants propagated by seeds had 187.52% more fruits than those grafted onto P. cincinnata. The use of rootstocks with P. cincinnata in sour passion fruit restricted the uptake of Na and Cl but reduced fruit production. [ABSTRACT FROM AUTHOR]

Polymeric films are used in numerous applications in the biomedical area. The incorporation of antimicrobial agents into these materials can prevent their surface from acting as a source of contamination of viruses and bacteria. In the present work, cinnamon and eucalyptus essential oils were incorporated into low‐density polyethylene (LDPE) by melt extrusion, as confirmed by Fourier transform infrared spectroscopy. For the success of incorporation, talc was used as an oil carrier and fixer. Despite high processing temperatures used (up to 175°C), the oleophilic character of talc was able to minimize oil losses, as proven by thermogravimetry. Good thermal and mechanical properties evaluated by differential scanning calorimetry and tensile tests were confirmed. In addition, antimicrobial tests confirmed film activity against virus SARS‐CoV‐2 and bacteria Staphylococcus aureus and Escherichia coli. LDPE films incorporated with both oils showed significant antiviral properties against SARS‐CoV‐2, with viral titers reduction between 95.89% and 100%. Cinnamon oil showed more efficient antibacterial properties than eucalyptus oil, with relative bacterial growths of films next to zero (0.37% for E. coli and 2.07% for S. aureus). To the best of our knowledge, no previous work has developed plastic films incorporated with essential oils with confirmed antiviral properties against SARS‐CoV‐2. [ABSTRACT FROM AUTHOR]

Earthworm colonization is an effective management practice to improve soil conditions. In a salt-affected reclamation soil, we conducted a mesocosm experiment to test the effects of organic residue application (no organic residues, clover residues or sheep manure) and plastic film (mulching or no mulching) on the survival, biomass and production of earthworms (Aporrectodea trapezoides (Duges, 1828)). Results showed that application of organic residues yielded a higher survival rate (37–100%) and biomass (0.43–0.98 g) of earthworms than the treatments without organic residue, regardless of plastic mulch. Moreover, the application of sheep manure significantly increased earthworm survival (58%) and biomass (160%) compared to the application of clover residues, which may be due to high soil available resources and nutrients in the soils with sheep manure. No significant differences (p = 0.26) in the survival rate (37–100% and 47–82%) or biomass of A. trapezoides were observed between the mulch and no-mulch treatments. This study indicated that animal manure out-performed clover residues in promoting the growth and survival of A. trapezoides in a reclaimed, salt-affected soil. Moreover, plastic film mulching improved soil moisture, but had no effect on the survival and biomass of A. trapezoides. [ABSTRACT FROM AUTHOR]

Although mulching is a widely used agronomic practice, its effects on the rhizosphere remain poorly understood. Here, we employed amplicon and transcriptomic sequencing to investigate variations in a grapevine rhizosphere system under mulch treatment (rice straw + felt + plastic film). Analyzing 16S and intergenic spacer (ITS) rRNA sequences indicated that the Shannon and Simpson indices of the bacterial and fungal communities increased markedly under mulch treatment. The bacterial and fungal compositions varied significantly between the control and mulch treatments. Mulching enriched for potentially beneficial microbes that confer disease resistance to plants or participate in nitrogen metabolism (Kaistobacter, Ammoniphilus, Lysobacter, Ammoniphilus, Alicyclobacillus, Aquicella, Nitrospira, Chaetomium, and Microascus), whereas more potentially pathogenic microbes (Fusarium and Gibberella) were detected in the control. Moreover, certain bacteria and fungi exhibited different correlations with the root transcriptome functions of the MEBlue module. The complexity of the bacterial and fungal co-occurrence networks increased with higher node numbers, positive and negative links after mulching. Following mulching, the rhizosphere showed elevated pH, organic matter, and catalase activities, and decreased sucrase and cellulase and β-glucosidase activities. Our results provide comprehensive data showing how a grapevine rhizosphere system responded to mulching treatment and shed important insight into mulching practices for fruit trees. [ABSTRACT FROM AUTHOR]

Serra da Estrela cheese with a Protected Designation of Origin (PDO) is a traditional cheese that is wrapped in paper without vacuum. High-pressure processing (HPP), which requires vacuum packaging of the cheese, has been used for its cold pasteurization to overcome safety issues. In this study, two packaging systems were studied: non-vacuum greaseproof paper wrapping package and vacuum packaging in plastic film. Lactococci, lactobacilli, enterococci, and total mesophiles reached ca. 8 log cfu g−1 and 4–6 log cfu g−1 in control (unpasteurized) and HPP-treated cheeses, respectively, with no significant differences between packaging systems. Spoilage microorganisms' viable cell numbers were reduced to <3 log cfu g−1 (quantification limit) in HPP-treated cheeses, independently of the packaging system. Yeasts and molds reached >5 log cfu g−1 in non-vacuum paper-wrapped cheeses. A vacuum-packaging system enabled better control of cheese proteolysis, which was revealed to be closer to that of the original control cheese values at the end of the 10-month storage period. In addition, cheese stored under vacuum film packaging became harder than non-vacuum paper-wrapped cheeses at each time point. Overall, conventional non-vacuum paper wrapping is adequate for short storage periods (<3 months), but for long periods vacuum packaging in plastic film is preferable. [ABSTRACT FROM AUTHOR]

The increase in the production of highly recalcitrant plastic materials, and their accumulation in ecosystems, generates the need to investigate new sustainable strategies to reduce this type of pollution. Based on recent works, the use of microbial consortia could contribute to improving plastic biodegradation performance. This work deals with the selection and characterization of plastic-degrading microbial consortia using a sequential and induced enrichment technique from artificially contaminated microcosms. The microcosm consisted of a soil sample in which LLDPE (linear low-density polyethylene) was buried. Consortia were obtained from the initial sample by sequential enrichment in a culture medium with LLDPE-type plastic material (in film or powder format) as the sole carbon source. Enrichment cultures were incubated for 105 days with monthly transfer to fresh medium. The abundance and diversity of total bacteria and fungi were monitored. Like LLDPE, lignin is a very complex polymer, so its biodegradation is closely linked to that of some recalcitrant plastics. For this reason, counting of ligninolytic microorganisms from the different enrichments was also performed. Additionally, the consortium members were isolated, molecularly identified and enzymatically characterized. The results revealed a loss of microbial diversity at each culture transfer at the end of the induced selection process. The consortium selected from selective enrichment in cultures with LLDPE in powder form was more effective compared to the consortium selected in cultures with LLDPE in film form, resulting in a reduction of microplastic weight between 2.5 and 5.5%. Some members of the consortia showed a wide range of enzymatic activities related to the degradation of recalcitrant plastic polymers, with Pseudomonas aeruginosa REBP5 or Pseudomonas alloputida REBP7 strains standing out. The strains identified as Castellaniella denitrificans REBF6 and Debaryomyces hansenii RELF8 were also considered relevant members of the consortia although they showed more discrete enzymatic profiles. Other consortium members could collaborate in the prior degradation of additives accompanying the LLDPE polymer, facilitating the subsequent access of other real degraders of the plastic structure. Although preliminary, the microbial consortia selected in this work contribute to the current knowledge of the degradation of recalcitrant plastics of anthropogenic origin accumulated in natural environments. [ABSTRACT FROM AUTHOR]

Black plastic film mulching is widely practiced in crop production, especially in horticultural systems, because of its multiple benefits. However, its post-usage polluting residues and limited availability to farmers at all places cause concern. The objective of this study was to evaluate in a field experiment the potential of the commonly available stationery-purpose poly-coated brown wrapping sheet mulching in bhendi [Abelmoschus esculentus (L.) Moench] in comparison with black plastic film mulching. Observations made on plant height and fruit yield, soil temperature and soil microbial population revealed that the less-polluting poly-coated brown wrapping sheet mulching was as good as the black plastic film mulching in performance which is discussed in the light of increase in plant growth and yield, moisture conservation and weed suppression, root-zone temperature moderation and termite activity. [ABSTRACT FROM AUTHOR]

The Brazilian semiarid region stands out in terms of sour passion fruit production. Local climatic conditions (high air temperature and low rainfall), combined with its soil properties (rich in soluble salts), increase salinity effects on plants. This study was carried out in the experimental area "Macaquinhos" in Remígio-Paraíba (Brazil). The aim of this research was to evaluate the effect of mulching on grafted sour passion fruit under irrigation with moderately saline water. The experiment was conducted in split-plots in a 2 × (2 × 2) factorial scheme to evaluate the effects of the combination of irrigation water salinity of 0.5 dS m−1 (control) and 4.5 dS m−1 (main plot), passion fruit propagated by seed and grafted onto Passiflora cincinnata, with and without mulching (subplots), with four replicates and three plants per plot. The foliar Na concentration in grafted plants was 90.9% less than that of plants propagated via seeds; however, it did not affect fruit production. Plastic mulching, by reducing the absorption of toxic salts and promoting greater absorption of nutrients, contributed to greater production of sour passion fruit. Under irrigation with moderately saline water, the plastic film in the soil and seed propagation promote higher production of sour passion fruit. [ABSTRACT FROM AUTHOR]

Abstract Purpose 211At, a promising alpha-particle-emitting radionuclide, can easily volatilize and contaminate the environment. To safely manage this unique alpha-particle-emitting radionuclide, we investigated the permeability of four types of plastic films and two types of rubber gloves against 211At and identified suitable materials that prevent contamination by 211At. Methods Four types of plastic films, polyethylene, polyvinylidene chloride, polyvinyl chloride, and a laminated film, and two types of rubber gloves, latex and nitrile, were examined. Small pieces of filter paper were covered with these materials, and a drop containing 100 kBq of 211At was placed on them. The radioactivity of the pieces of filter paper under the materials was evaluated by measuring counts using a gamma counter and obtaining autoradiograms 3.5 h later. These experiments were also performed using 225Ac, 125I, 111In, 201Tl, and 99mTc. Results 211At solution easily penetrated polyethylene, polyvinyl chloride, and latex rubber. Similar results were obtained for 125I, while other radionuclides did not penetrate films or gloves. These results suggest that halogenic radionuclides under anionic conditions are likely to penetrate plastic films and rubber gloves. Conclusion Our evaluation revealed that, when 211At solution is used, the protection by polyvinylidene chloride, a laminated film, or nitrile rubber would be more effective than that by polyethylene, polyvinyl chloride, or latex rubber.

In semi-arid regions, agricultural production is often limited due to scarcity and rainfall irregularities, and, therefore, the production system depends on irrigation. In this direction, the research aimed to evaluate the influence of the reduction of water losses in the soil through the coating of the lateral faces of the planting furrows with plastic film, by lateral infiltration of water and bovine biofertilizers for growth in height, production, and chlorophyll responses of tomato cv. Fascínio F1 irrigated with moderately saline water. The experiment was carried out in randomized blocks, in a 2 × 3 factorial scheme, with 4 replicates and 21 plants per plot. Different conditions were used and compared with each other: the furrow had side coating or not, and the soil received a common biofertilizer (fresh lactating bovine manure), chemically enriched fertilizer (common biofertilizer, milk, molasses, and gypsum), or no fertilizer at all. The variables evaluated were soil moisture, plant height, a, b, and total chlorophyll content, number and average fruit mass, tomato production, and productivity. The enriched bovine biofertilizer associated with the lateral furrow coating increased the synthesis of chlorophyll pigments, the number of fruits per plant, and the productivity of tomato cv. Fascínio F1. Protecting the faces of the furrows against water losses from the root environment of plants keeps the soil moist, stimulates the synthesis of chlorophyll, and increases the average mass of the fruits. The common bovine biofertilizer promotes greater growth in plant height, and the chemically enriched biofertilizer increases the average weight of tomato fruits.

The increase in the production of highly recalcitrant plastic materials, and their accumulation in ecosystems, generates the need to investigate new sustainable strategies to reduce this type of pollution. Based on recent works, the use of microbial consortia could contribute to improving plastic biodegradation performance. This work deals with the selection and characterization of plastic-degrading microbial consortia using a sequential and induced enrichment technique from artificially contaminated microcosms. The microcosm consisted of a soil sample in which LLDPE (linear low-density polyethylene) was buried. Consortia were obtained from the initial sample by sequential enrichment in a culture medium with LLDPE-type plastic material (in film or powder format) as the sole carbon source. Enrichment cultures were incubated for 105 days with monthly transfer to fresh medium. The abundance and diversity of total bacteria and fungi were monitored. Like LLDPE, lignin is a very complex polymer, so its biodegradation is closely linked to that of some recalcitrant plastics. For this reason, counting of ligninolytic microorganisms from the different enrichments was also performed. Additionally, the consortium members were isolated, molecularly identified and enzymatically characterized. The results revealed a loss of microbial diversity at each culture transfer at the end of the induced selection process. The consortium selected from selective enrichment in cultures with LLDPE in powder form was more effective compared to the consortium selected in cultures with LLDPE in film form, resulting in a reduction of microplastic weight between 2.5 and 5.5%. Some members of the consortia showed a wide range of enzymatic activities related to the degradation of recalcitrant plastic polymers, with Pseudomonas aeruginosa REBP5 or Pseudomonas alloputida REBP7 strains standing out. The strains identified as Castellaniella denitrificans REBF6 and Debaryomyces hansenii RELF8 were also considered relevant members of the consortia although they showed more discrete enzymatic profiles. Other consortium members could collaborate in the prior degradation of additives accompanying the LLDPE polymer, facilitating the subsequent access of other real degraders of the plastic structure. Although preliminary, the microbial consortia selected in this work contribute to the current knowledge of the degradation of recalcitrant plastics of anthropogenic origin accumulated in natural environments.

• Explored the optimum pyrolysis temperature and activation conditions of MPS. • The quantized promotion degree of maize growth by MPS-char was obtain. • Nitrogen release delayed and concentration was improved by 16% with MPS-char. • Physical property of MPS-char mad the root development advance than others. Pyrolyzing and returning to farmland is one of the potential methods for farmland plastic film waste. This study explored both pyrolyzation and activation optimum conditions of a mixture of plastic film (polyethylene) and maize straw (MPS) in a 1:5 ratio to produce MPS-char, investigated the action of the char on the maize seedling stage (for 30 days). The results showed that the char promoted the root to be more advanced than aboveground part, therefore, this study experimentally clarified the role MPS-char played when added to the soil. The functional groups of the char were varied by the participation of polyethylene. Carbon-based groups were observed, such as carbonyl or carboxyl groups, which could constitute an NH 4 + absorption release system to increase the existence of urea in soil, therefore the average nitrogen concentration was improved by 16.18 %. However, the shallow soil temperature increased by 2.03 °C, and the deep soil temperature slightly decreased with the effect of MPS-char. While, the soil moisture content was slightly reduced in the second half of the experiment, and the soil oxygen content increased by 7.64 % throughout the whole experiment. Overall, returning MPS-char to farmland showed a positive effect on maize growth, which was caused by the variation of both chemical and physical properties. This variation provides opportunities for further promotion of rhizosphere development. [ABSTRACT FROM AUTHOR]

Investigating the use and recycling of plastic films by different agricultural business entities can systematically determine the impact of different business modes on the use and recycling of plastic film and provide suggestions for the prevention and control of related pollution. Therefore, three provinces in northern China（Liaoning, Inner Mongolia, and Gansu）were selected as sites to investigate the use and recycling of plastic film by traditional farmers, stakeholders of large farms（planting area>6.67 hm² ）, and cooperatives. In this study, the average mulching area, intensity of mulching plastic film used, mulching thickness, and coverage rate of main crops were investigated to determine the characteristics of mulch film use for different agricultural business entities. The recovery operation rate, recovery methods, and treatment of plastic film after recovery were considered to compare the characteristics of methods of recycling plastic film. The main crops covered by plastic film in the three provinces were corn, open field vegetables, potatoes, sunflowers, and peanuts. Compared with traditional farmers, the rate of plastic film mulching was 7.54 percent points for stakeholders of large farms and 8.50 percent points higher for cooperatives. Cooperatives had the highest-intensity use of mulching plastic film 86.41 kg · hm-2 on average, which was 4.37% and 19.81% higher, respectively, than those of traditional farmers and stakeholders of large farms. No substantial differences were observed in the thickness of the mulch film used in different agricultural business entities. Cooperatives had the highest mechanization rate（48.29%） for plastic film recovery, which was 27.85 percent points and 10.92 percent points higher than those of traditional farmers and stakeholders of large farms, respectively. The plastic film recycling operation rates were higher than 85% for all kinds of agricultural business entities, with traditional farmers and cooperatives having rates that were 1.04 percent points and 1.65 percent points higher, respectively, than those of stakeholders in large farms. Our results showed that large-scale and organized operators, such as cooperatives and stakeholders in large farms, are more inclined to use plastic film mulching technology, and their use and recycling behaviors are more environmentally friendly. Promoting the development of new operators can thus effectively solve the problem of plastic film pollution. [ABSTRACT FROM AUTHOR]

In semi-arid regions, agricultural production is often limited due to scarcity and rainfall irregularities, and, therefore, the production system depends on irrigation. In this direction, the research aimed to evaluate the influence of the reduction of water losses in the soil through the coating of the lateral faces of the planting furrows with plastic film, by lateral infiltration of water and bovine biofertilizers for growth in height, production, and chlorophyll responses of tomato cv. Fascínio F1 irrigated with moderately saline water. The experiment was carried out in randomized blocks, in a 2 × 3 factorial scheme, with 4 replicates and 21 plants per plot. Different conditions were used and compared with each other: the furrow had side coating or not, and the soil received a common biofertilizer (fresh lactating bovine manure), chemically enriched fertilizer (common biofertilizer, milk, molasses, and gypsum), or no fertilizer at all. The variables evaluated were soil moisture, plant height, a, b, and total chlorophyll content, number and average fruit mass, tomato production, and productivity. The enriched bovine biofertilizer associated with the lateral furrow coating increased the synthesis of chlorophyll pigments, the number of fruits per plant, and the productivity of tomato cv. Fascínio F1. Protecting the faces of the furrows against water losses from the root environment of plants keeps the soil moist, stimulates the synthesis of chlorophyll, and increases the average mass of the fruits. The common bovine biofertilizer promotes greater growth in plant height, and the chemically enriched biofertilizer increases the average weight of tomato fruits. [ABSTRACT FROM AUTHOR]

Recently, the use of plastics has become more widespread due to the vital role they play in daily life and human health. Plastic decomposes into microplastic (MP) in the soil. Owing to the negative consequences of soil MPs' growth on both soil and human health, several studies conducted over the past 10 years have concentrated on identifying and tracking the origins of MPs in soil. These studies have demonstrated that soil MPs originate from a range of sources, including plastic films, fertilizers, runoff, sewage sludge, irrigation, and the atmosphere. Despite the efforts made to identify specific sources of soil MPs, a thorough analysis and comparison of the primary sources is still absent. By assembling the results of earlier research that demonstrate how irrigation, the atmosphere, and sewage sludge all contribute to the richness of soil MP, this review will aid in filling this knowledge gap. The MP abundance from each of these sources was compared using an analysis of variance (ANOVA). The results of this investigation showed that plastic films are the largest and most significant contributors to soil microplastic contamination, owing to human overdependence on plastic films . Air deposition is the least common source of MPs . The amount of MP did not differ noticeably across irrigation, runoff, sewage sludge, and plastic film. This is because no nterference occurs when MPs from these sources interact with the soil. The findings of this study will be useful for choosing effective management and control techniques for sources of soil MP. [ABSTRACT FROM AUTHOR]

Polyethylene plastic bags manufactured via blown film extrusion have different quality specifications depending on their intended use. It is known that the mechanical properties of a film depend on the process parameters established, but little is known concerning how they affect one another, even more so due to the variety of polyethylene materials and processing techniques. This study focuses on establishing a proper correspondence of important mechanical properties like the dart impact, tensile strength at break, and elongation at break with commonly used process parameters like the blow-up ratio, take-up ratio, thickness reduction, and neck height, for a high-density polyethylene hexene copolymer and a linear low-density polyethylene butene copolymer blend film. Because this polyethylene mixture is an anisotropic material, interesting R2 values equal to or higher than 0.90 were found: a BUR with elongation at break and tensile strength at break in the MD and TD, a TUR with elongation at break in the MD and tensile strength at break in the MD and TD, and a TR with elongation at break and tensile strength at break in the MD. Also, a relationship between the dart impact and both the neck height and thickness were found.

Abstract The increasing demand for applying modified inert atmosphere systems for insect eradication in museums has led to the desire for lower-cost consumable materials, particularly laminated plastic films. An ultra-low oxygen-permeable laminate is required for creating successful systems of modified inert atmosphere to keep the oxygen concentration lower than 0.3%. A range of ultra-high barrier laminates is commercially available but at a high cost, which could affect the sustainability of applying these systems in museums of limited budgets. The wide use of local laminates for food preservation makes them a perfect target for testing and improvement as alternatives. However, a laboratorial test method for evaluating their oxygen permeability is required to assess their suitability for insect eradication using modified atmospheres. Therefore, the present work investigates the potential of using two laminates (one local and one imported) to create a successful modified atmosphere system. A laboratory easy-to-use test method was used to assess the oxygen permeability of each laminate and calculate its oxygen transmission rate. The test method is a sealed static chamber separated in the middle by a known area of the laminate to be tested. The test relies on monitoring the change of oxygen concentration overtime on either side of the laminate membrane within the sealed system to assess its oxygen transmission rate. The specifications and design of the test chamber are adopted from the ASTM Designation: E2945 − 14. Results indicated that the new method is useful for an unlimited number of tests of an unlimited number of laminates. The conducted tests proved that the local laminate normally used for food packaging showed good results in terms of its oxygen transmission rate.

Agricultural soil contamination with plastic film has become a critical global environmental problem, requiring greater research on the possible occurrence and biological risk of microplastics (MPs) and their additives in soil ecosystems. The presence of MPs and tris (2-chloroethyl) phosphate (Tcep) in agricultural soil was investigated at nine sites in the present study. Polyethylene MPs (PE-MPs) and Tcep were found at all nine sites. To study co-exposure effects on soil microbiota and earthworms, and to mimic a realistic exposure scenario, 0.05 % (w/w) PE-MPs with three particle size ranges were combined with Tcep (1.0 mg/kg). After 28 days of exposure, there was no indication that added PE-MPs and/or Tcep significantly affected the soil microbial community structure. In earthworms, size-selective intake, digestion and egestion of PE-MPs may occur, with Tcep co-exposure affecting the residual Tcep concentration in earthworm intestines (3.52–9.31 μg/g dw). Long-term earthworm PE-MPs intake caused intestinal damage, and Tcep co-exposure increased oxidative stress, thereby influencing their feeding behavior and growth, resulting in weight loss (3.42 %–14.96 %), especially for the most common PE-MPs sizes (0–300 μm). High performance liquid chromatography-mass spectrometry (LC-MS) was used for metabolomic analysis, revealing the significant up-regulation of citrate (p

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Plastic film has been widely used as one of the most important materials in various agricultural fields, due mainly to the chemical stability, thinness, and light properties. At the same time, the mechanical properties of plastic film can be the main research direction of film structure design in recent years. In this study, the experiment and numerical simulation were carried out for the damage analysis of plastic film under the hail impact. Among them, the air cannon test device was used to analyze the failure form and damage law of plastic film under hail impact. A high-speed camera and laser speed meter were then utilized to record the deformation process and energy absorption of plastic film that impacted by the ice ball. The finite element method (FEM) was also selected to evaluate the structural parameters of plastic film using ABAQUS software. The error analysis was performed on the failure area and the energy absorption of the plastic film, in order to verify the effectiveness of the numerical simulation. There was the relatively small error of the experimental and numerical simulation, indicating the better performance of the simulation. The plastic film under ice ball impact was also analyzed as follows. Firstly, the different sizes of the ice ball were selected to evaluate the impact angles of the ice ball impact plastic film. Secondly, the simulation was carried out in the the single and secondary impact of the ice ball impact on the plastic film. Finally, the ice ball impact plastic film was simulated with the different thicknesses and ice impacting double-layer plastic film with different distances between layers. The failure form and energy absorption of the plastic film were achieved in the better performance after numerical simulation. The following results were obtained: 1) The plastic film with the 0.12 mm thickness efficiently resisted the impact of hail with a diameter of less than 10 mm. Once the hail size was more than 30 mm, the plastic film was damaged rapidly, due to the action of the tensile stress wave. In addition, there was the larger damaged area that caused by the ellipsoidal hockey ball impact plastic film than that by the spherical one. 2) The secondary impact of the ice ball on the plastic film caused the superposition of stress waves, leading to the accelerated destruction of the film. 3) The largest damaged area of the film was observed, when the ice ball impact angle was 60° at the ice ball impact angle of 0°, 30° and 60°. 4) The damaged area of the double-layer film greatly increased with the increase of the distance between the plastic films. The anti-hail impact effect of the double-layer plastic film was better than that of the single-layer plastic film with the same thickness, when the distance between the double-layer plastic films was controlled within 5 mm. Therefore, the numerical simulation can be used to analyze the damage of plastic film under the impact of the ice ball. The tensile strength of plastic film can also be improved the better ability of hail impact resistance. This finding can provide a strong reference for the structural design and damage analysis of thin films. [ABSTRACT FROM AUTHOR]

In semiarid regions of Brazil, water and/or soil salinity is one of the limiting factors for sour passion fruit production. Low rainfall rates combined with edaphic conditions (high concentrations of soluble salts) intensify deleterious effects on plants. Thus, strategies that minimize the effects of salt stress, e.g., grafting with tolerant species and soil mulching, are extremely important to ensure the expansion of irrigated fruit farming in this region. From this perspective, this study aimed to evaluate the effect of grafting and mulching on the quantum yield, ionic relations, and fruit production of sour passion fruit irrigated with moderately saline water. The experiment was conducted under field conditions in split plots, in a 2 × (2 × 2) factorial arrangement to evaluate the combination of low and moderate salinity water (main plot) with the propagation method (seeds and grafting on P. cincinnata) and without and with plastic mulching (subplots), with four replications and three plants per plot. The ionic relations in passion fruit leaves were increased with the use of rootstocks and plastic mulching under irrigation with moderately saline water. The use of mulching increased the yield of photosystem II in sour passion fruit. The passion fruit plants propagated by seeds had 187.52% more fruits than those grafted onto P. cincinnata. The use of rootstocks with P. cincinnata in sour passion fruit restricted the uptake of Na and Cl but reduced fruit production.

Although mulching is a widely used agronomic practice, its effects on the rhizosphere remain poorly understood. Here, we employed amplicon and transcriptomic sequencing to investigate variations in a grapevine rhizosphere system under mulch treatment (rice straw + felt + plastic film). Analyzing 16S and intergenic spacer (ITS) rRNA sequences indicated that the Shannon and Simpson indices of the bacterial and fungal communities increased markedly under mulch treatment. The bacterial and fungal compositions varied significantly between the control and mulch treatments. Mulching enriched for potentially beneficial microbes that confer disease resistance to plants or participate in nitrogen metabolism (Kaistobacter, Ammoniphilus, Lysobacter, Ammoniphilus, Alicyclobacillus, Aquicella, Nitrospira, Chaetomium, and Microascus), whereas more potentially pathogenic microbes (Fusarium and Gibberella) were detected in the control. Moreover, certain bacteria and fungi exhibited different correlations with the root transcriptome functions of the MEBlue module. The complexity of the bacterial and fungal co-occurrence networks increased with higher node numbers, positive and negative links after mulching. Following mulching, the rhizosphere showed elevated pH, organic matter, and catalase activities, and decreased sucrase and cellulase and β-glucosidase activities. Our results provide comprehensive data showing how a grapevine rhizosphere system responded to mulching treatment and shed important insight into mulching practices for fruit trees.

Purpose: 211At, a promising alpha-particle-emitting radionuclide, can easily volatilize and contaminate the environment. To safely manage this unique alpha-particle-emitting radionuclide, we investigated the permeability of four types of plastic films and two types of rubber gloves against 211At and identified suitable materials that prevent contamination by 211At. Methods: Four types of plastic films, polyethylene, polyvinylidene chloride, polyvinyl chloride, and a laminated film, and two types of rubber gloves, latex and nitrile, were examined. Small pieces of filter paper were covered with these materials, and a drop containing 100 kBq of 211At was placed on them. The radioactivity of the pieces of filter paper under the materials was evaluated by measuring counts using a gamma counter and obtaining autoradiograms 3.5 h later. These experiments were also performed using 225Ac, 125I, 111In, 201Tl, and 99mTc. Results: 211At solution easily penetrated polyethylene, polyvinyl chloride, and latex rubber. Similar results were obtained for 125I, while other radionuclides did not penetrate films or gloves. These results suggest that halogenic radionuclides under anionic conditions are likely to penetrate plastic films and rubber gloves. Conclusion: Our evaluation revealed that, when 211At solution is used, the protection by polyvinylidene chloride, a laminated film, or nitrile rubber would be more effective than that by polyethylene, polyvinyl chloride, or latex rubber. [ABSTRACT FROM AUTHOR]

Producing more food with a lower environmental cost is one of the most crucial challenges worldwide. Plastic mulching has developed as one of the most dominant practices to improve crop yields, however its impacts on greenhouse gas (GHG) emissions during the production life cycle of a crop are still unclear. The objective of this work is to quantify the impacts of plastic film on GHG emissions and to reduce GHG emissions with innovative agronomic practices. Carbon footprint per unit of area (CFa), per unit of maize grain yield (CFy), and per unit of economic output (CFe) were evaluated for three maize cultivation systems: a no mulch system, a conventional plastic mulching system (PM) and a biennial plastic mulching pattern, namely a ‘one film for 2 years' system (PM2), during 2015–2018 in a maize field located on the Loess Plateau of China. The results suggested that PM induced a 24% improvement in maize yields during the four experimental years compared to a no-mulch treatment (NM). However, PM dramatically increased the CFa by 69%, 59% of which was created by the input of the plastic film material, and 10% was created by increases in the soil N2O emissions. The yield improvements from PM could not offset the increases in CFa, and CFy and CFe were both increased by 36%. Shifting from PM to PM2 did not reduce crop yields, but it led to a 21% reduction in CFa and 23% reductions in CFy and CFe due to the reduced input amount of plastic film, decreased soil N2O emissions, and less diesel oil used for tillage. Compared to NM, CFy and CFe were only 5% higher in PM2. This study highlights the necessity of reducing the amount of plastic film input in the development of low-carbon agriculture and shifting from conventional PM cultivation to PM2 could be an efficient option for mitigating GHG emissions while sustaining high crop yields in plastic mulched fields.

ABSTRACT This study aimed to evaluate the productive performance, dry matter intake, apparent digestibility and ingestive behavior of feedlot calves fed corn silage from the feed out face of trench silos with different types of sealing. The animals were divided into three treatments with four repetitions: Conventional seal - double-sided polyethylene of 110µm thickness; Double-sided seal - double-sided polyethylene of 200µm thickness; and Double seal - composed of double face polyethylene with a thickness of 80µm superimposed on a polyamide translucent vacuum film with a thickness of 20µm. The use of double face sealing provided 12.63% increase in average daily gain and improved food conversion by 0.62 percentage points. The apparent digestibility of the diet with double-face sealing system silage was 4.30% higher than the diet with double-face sealing silage and 11.00% higher than the diet with conventional sealing silage. It is recommended to use the double face sealing with 200µm polyethylene and double face sealing with 80µm thick polyethylene on top of a 20µm thick polyamide translucent vacuum film.

Abstract The objective of this work was to evaluate the influence of different soil coverings, fertilizer types, and soil conditioners on the incidence and severity of brown eye spot (Cercospora coffeicola) in coffee (Coffea arabica) during the vegetative stage. The experiment was carried out in a randomized complete block design, in a 3×2×5 factorial arrangement (soil coverings × fertilizer types × soil conditioners) in subdivided plots, with three replicates. Comparisons were made among: three soil covering (plastic film, Urochloa decumbens, and no covering) in the plots; two fertililizer types (conventional and controlled release) in the sub-plots; and four soil conditioners (coffee husk, agricultural gypsum, water retention polymer, and organic compound), as well as the control, in the sub-sub-plots. The area under the progress curve for disease incidence and severity showed the lowest mean without soil covering, whereas that for number of leaves was greater with the use of the controlled-release fertilizer. The plastic film provided a greater soil moisture and a lower soil resistance penetration. The chemical composition of the organic compound reduced coffee plants growth. Soil covering with plastic film or U. decumbens favors the high incidence of brown eye spot; however, it provides a greater soil moisture and, therefore, improves the growth of coffee plants in the vegetative stage.

Serra da Estrela cheese with a Protected Designation of Origin (PDO) is a traditional cheese that is wrapped in paper without vacuum. High-pressure processing (HPP), which requires vacuum packaging of the cheese, has been used for its cold pasteurization to overcome safety issues. In this study, two packaging systems were studied: non-vacuum greaseproof paper wrapping package and vacuum packaging in plastic film. Lactococci, lactobacilli, enterococci, and total mesophiles reached ca. 8 log cfu g−1 and 4–6 log cfu g−1 in control (unpasteurized) and HPP-treated cheeses, respectively, with no significant differences between packaging systems. Spoilage microorganisms' viable cell numbers were reduced to −1 (quantification limit) in HPP-treated cheeses, independently of the packaging system. Yeasts and molds reached >5 log cfu g−1 in non-vacuum paper-wrapped cheeses. A vacuum-packaging system enabled better control of cheese proteolysis, which was revealed to be closer to that of the original control cheese values at the end of the 10-month storage period. In addition, cheese stored under vacuum film packaging became harder than non-vacuum paper-wrapped cheeses at each time point. Overall, conventional non-vacuum paper wrapping is adequate for short storage periods (

Biodegradable plastics, such as poly(butylene adipate terephthalate) (PBAT) and polylactic acid (PLA), are potential alternatives to conventional polyethylene (PE), both of which are associated with the production of microplastics (MPs). However, the toxicity of these compounds on medicinal plants and their differential effects on plant morphophysiology remain unclear. This study supplemented soils with MPs sized at 200 μm at a rate of 1% w/w and incubated them for 50 days to investigate the impact of MPs on the growth and metabolites of dandelion (Taraxacum mongolicum Hand.-Mazz.). The results demonstrated that the investigated MPs decreased the growth of dandelion seedlings, induced oxidative stress, and altered the activity of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase). Based on the comprehensive toxicity assessment results, the ecological toxicity was in the following order: PE MPs > PBAT MPs > PLA MPs. Metabolomics analyses revealed metabolic reprogramming in dandelion plants, leading to the enrichment of numerous differentially accumulated metabolites (DAMs) in the leaves. These pathways include carbohydrate metabolism, energy metabolism, and biosynthesis of secondary metabolites, suggesting that dandelions respond to MP stress by enhancing the activity of sugar, organic acid, and amino acid metabolic pathways. In addition, phenolic acids and flavonoids are critical for maintaining the balance in the antioxidant defense system. Our results provide substantial insights into the toxicity of biodegradable MPs to plants and shed light on plant defense and adaptation strategies. Further assessment of the safety of biodegradable MPs in terrestrial ecosystems is essential to provide guidance for environmentally friendly management. [Display omitted] • Both conventional and biodegradable microplastics (MPs) inhibited dandelion growth. • Polyethylene MPs had bigger phytotoxicity on dandelion than biodegradable MPs. • MPs up-regulated the carbohydrate and energy metabolism of dandelion. • Exposure of dandelion to MPs affected phenolic acids and flavonoid biosynthesis. [ABSTRACT FROM AUTHOR]

In order to explore the effects of plastic film mulching cultivation on the main agronomic characters, yield and quality of peanut, a new high-yield and high-quality resistant peanut variety Quanhua 557 was used as the test material. By using the single factor randomized block design, the effects of different plastic film mulching (color matching plastic film, silver-gray plastic film, black plastic film, ordinary plastic film and degradable plastic film) on its germination rate, yield and quality were studied with the bare land as the control group. The results showed that, compared with the control group, the treatment of plastic film mulching could significantly improve the yield of peanut, and the yield increased to a very significant level. The higher yield of plastic film mulching cultivation resulted from the advantages of higher productivity per plant and earlier entry into the yield formation period. The yield of peanut with different plastic film mulching treatments was in order as follows: silver-gray plastic film, black plastic film, ordinary plastic film, degradable plastic film and color matching plastic film. The fat content and linoleic acid content in peanut were higher than those in the control group, while the protein content and oleic acid content in the control group were the highest, but there was no significant difference in the quality of peanut among d辻ferent treatments. [ABSTRACT FROM AUTHOR]

Caesalpinia sappan L. wood fiber (CSWF), a novel advanced bio-reinforcement for polybutylene succinate (PBS) composite films, has shown significant promise ranging from 0 to 15 part per hundred of resin (phr). The functional groups and interactions, morphology, thermal stability, mechanical characteristics, and biodegradability were all investigated. Without treatment or any compatibilizers, CSWF could be well-dispersed in the PBS matrix. The PBS/CSWF10 composite film had highest mechanical strength, with a tensile strength of 12.21 N/mm2 and a break elongation of 21.01%. Biodegradability studies indicated that the PBS/CSWF10 composite films degraded completely in three months. Furthermore, the Ea of degradation resulting from TGA and the shift of wavenumber resulting from FTIR revealed that the addition of CSWF has a greater interaction between additive and martix than conventional cellulose. The PBS/CSWF10 composite has the potential to be environmentally friendly, with promising short-term degradation and rising mechanical characteristics. Therefore, it is the optimum concentration of a certain biocomposite film. As a result, a novel advanced natural-based cellulose for biopolymer composites film was discovered, as well as other benefits for bio-reinforcement of the green plastic composite film industry. [ABSTRACT FROM AUTHOR]

The spread of biodegradable plastic films (BDFs) not only increases grain yield but also reduces environmental pollution from plastic film to a large extent. Soil microbes are considered to be involved in biodegradation processes. However, the study of microbe diversity in soil mulched with biodegradable plastic film remains limited. Here, we compared the diversity of microbes between soils with biodegradable film and nonbiodegradable film (NBDF) mulch. The results showed that BDFs affected total C, P and NH4+-N, especially organism C content, as well as microbe species richness (ACE; Chao1) and diversity (Simpson index; Shannon index). In terms of dominant phyla and genera, BDFs and NBDF can influence the abundance of disparate species. Furthermore, BDFs could also contribute to improving the richness of the important functional bacterial groups in soil, e.g., Pedomicrobium and Comamonas, both of which are involved in the degradation of plastic residues in soil. Finally, we found that BDFs improved the transformation of nitrogen by significantly increasing the abundances of Nitrobacter and Nitrospira. Our results highlight the impact of BDF mulch on the abundance of functional bacteria in the soil. [ABSTRACT FROM AUTHOR]

Okra (Abelmoschus esculentus L. Moench) is a vegetable crop of high nutritional value, which presents great losses after harvest when stored under poor storage conditions. The objective of this research was to evaluate the effect of different low-density polyethylene (LDPE) thicknesses on the preservation and post-harvest quality of okra fruits under different storage periods. The experiment was conducted in a completely randomized design, with nine replicates, in a 5 × 5 factorial scheme, corresponding to five forms of packaging at a temperature of 10 ± 1 ℃: no film and four LDPE thicknesses (10, 20, 30, and 40 µm) with five storage periods (0, 7, 14, 21, and 28 days). It was revealed that the use of LDPE plastic films provided lower loss of mass, higher fruit firmness containment of increase in soluble solids, and lower color change at 21 days of storage compared to no film. The LDPE thickness of 30 µm showed lower incidence of rotting, better appearance throughout storage, lower color changes, containment of increase in soluble solids content, higher chlorophyll, ascorbic acid, and total phenolic content compared to other forms of packaging, and is the most appropriate package for storing okra fruits up to 21 days, under refrigeration condition. The results of this study show that the thickness of LDPE has significant effects on the conservation and quality of okra. Our findings can be used to minimize post-harvest losses of okra during marketing.

The increasing demand for applying modified inert atmosphere systems for insect eradication in museums has led to the desire for lower-cost consumable materials, particularly laminated plastic films. An ultra-low oxygen-permeable laminate is required for creating successful systems of modified inert atmosphere to keep the oxygen concentration lower than 0.3%. A range of ultra-high barrier laminates is commercially available but at a high cost, which could affect the sustainability of applying these systems in museums of limited budgets. The wide use of local laminates for food preservation makes them a perfect target for testing and improvement as alternatives. However, a laboratorial test method for evaluating their oxygen permeability is required to assess their suitability for insect eradication using modified atmospheres. Therefore, the present work investigates the potential of using two laminates (one local and one imported) to create a successful modified atmosphere system. A laboratory easy-to-use test method was used to assess the oxygen permeability of each laminate and calculate its oxygen transmission rate. The test method is a sealed static chamber separated in the middle by a known area of the laminate to be tested. The test relies on monitoring the change of oxygen concentration overtime on either side of the laminate membrane within the sealed system to assess its oxygen transmission rate. The specifications and design of the test chamber are adopted from the ASTM Designation: E2945 − 14. Results indicated that the new method is useful for an unlimited number of tests of an unlimited number of laminates. The conducted tests proved that the local laminate normally used for food packaging showed good results in terms of its oxygen transmission rate. [ABSTRACT FROM AUTHOR]

Introduction. Modern food industry needs composite polymer materials based on natural compounds that accelerate the biodegradability of packaging materials. Starch is one of the most effective organic fillers. It has an excellent compatibility with synthetic polymers during extrusion. The research objective was to perform a comparative assessment of the physical and mechanical characteristics of thermoplastic starch based on enzymatic modified porous corn starch. The starch included samples both purified and unrefined from reducing substances. The samples were tested in biodegradable film production. Study objects and methods. The research featured porous starch, hybrid compositions with thermoplastic porous starch (TPS), and films based on low density polyethylene (PLD). The study involved various methods for determining biochemical and structural features of starch, e.g. electron microscopy, and physicomechanical properties of compositions and films. Results and its discussion. Compared to native starch, porous starch had a 1.6 times higher water-binding capacity and a 4 times greater solubility. Its enzymatic attackability was 24% higher, while its dynamic viscosity was a 1.7 times lower. These properties had a positive effect on the biodegradability of the films. The film samples that had the PLD:TPS ratio of 60:40 and the porous starch ratio of 40:60 demonstrated higher indicators of breaking tensile stress than the native starch samples. When the ratio of PLD:TPS was 70:30, the difference reached 14%; with that of 60:40 – 23%. Similar results were obtained for the break elongation: the indicator increased by 74% at the ratio of 70:30, by 65% at the ratio of 60:40, and by 21% at 40:60. The superior tensile stress indicator of the porous starch samples proved its higher strength properties, while the better break elongation results denoted a greater biodegradability. Conclusion. Modified starch, unrefined from reducing substances, proved more expedient for TPS and PLD film production. Unlike refined starch, it reduced the biodegradability period of the final product. The biodegradability period can be specified in a prospective study of food properties during storage using the new film.

The contribution is focusing on the work of the Czech artist Jana Skalická (1957–2015), who was actively creating during the 1980s and the first half of 1990s. At the beginning of her career Skalická worked mainly with textiles, but later on she found a new material, which was better suited for her artistic expression – a plastic film. She was modifing the thin plastics with her own technique, using an iron or a sewing machine. Her art gradually developped from hanging plastic tapestries to three dimensional objects and installations, in which other materials, such as metal, wood, stones and other types of plastic, were incorporated. The majority of Skalická’s works was of an ephemere nature and was not conserved until today. The article is therefore dealing with their photographic depictionand its meaning.