Level Of Degradation Research Articles

Insights from land sparing and land sharing frameworks for land productivity degradation governance in the Yangtze River Delta urban agglomeration, China

AbstractLand degradation due to mismanagement is widespread globally and may threaten the achievement of several UN Sustainable Development Goals. Yet the differences in land productivity degradation under various land management patterns (land sparing vs. land sharing) are poorly known. In this research, we used remote sensing data to develop a machine learning model for assessing the risk of land productivity degradation and interpreted the model using state‐of‐the‐art interpretable artificial intelligence techniques. In 2018, the risk level of land productivity degradation in the agricultural production space of the Yangtze River Delta urban agglomeration (YRD) was 0.230. More than half of the area was at low risk (68.19% of the area), mainly in mountainous and hilly areas. The degradation risk of the land sharing management pattern is lower than that of the land sparing pattern, but there are significant differences among provinces/municipalities. The four most influential factors for land productivity degradation in YRD were Normalized Vegetation Difference Index, nighttime light, elevation, and nitrogen deposition, which together explained 72.75% of the degradation risk. This study provides a methodological framework for land degradation governance in emerging urban agglomerations. It strongly recommends that policymakers explore locally appropriate land management patterns based on regional contexts.

Towards automated field ballast condition evaluation: Field validation of the ballast scanning vehicle capabilities

Ballast degradation can lead to adverse effects such as inadequate drainage, track settlement and reduced lateral stability, which could compromise track safety, daily functionality, and long-term maintenance. Field inspection of ballast for monitoring degradation and functional performance is a challenging task. Current state-of-the-practice methods for evaluating ballast primarily depend on subjective visual inspection, labor-intensive sampling, laboratory sieve analyses or Ground Penetrating Radar (GPR) technology. These methods fall short in providing an in-depth assessment of ballast, specifically in determining the degradation level and aggregate size and shape characteristics at various depths. In this regard, this research developed an innovative ballast investigation platform, the Ballast Scanning Vehicle (BSV), to automate the processes of acquiring detailed ballast inspection data. The BSV utilizes a deep learning-based pipeline for image segmentation to evaluate task-specific metrics such as coarse aggregate gradation, Fouling Index (FI), and continuous track FI depth profiles. This paper provides a detailed overview of the BSV’s functions as well as the different modules of the deep learning-based pipeline. Validation of the BSV’s capabilities was conducted at the Transportation Technology Center (TTC) and is discussed in detail. Based on the field results, the BSV is capable of providing accurate and near real-time evaluation of in-service ballast conditions, serves as a robust means for inspecting long sections of track, and can be used to investigate persistent trouble-spots related to track performance.

MRNA-encoded Cas13 treatment of Influenza via site-specific degradation of genomic RNA.

The CRISPR-Cas13 system has been proposed as an alternative treatment of viral infections. However, for this approach to be adopted as an antiviral, it must be optimized until levels of efficacy rival or exceed the performance of conventional approaches. To take steps toward this goal, we evaluated the influenza viral RNA degradation patterns resulting from the binding and enzymatic activity of mRNA-encoded LbuCas13a and two crRNAs from a prior study, targeting PB2 genomic and messenger RNA. We found that the genome targeting guide has the potential for significantly higher potency than originally detected, because degradation of the genomic RNA is not uniform across the PB2 segment, but it is augmented in proximity to the Cas13 binding site. The PB2 genome targeting guide exhibited high levels (>1 log) of RNA degradation when delivered 24 hours post-infection in vitro and maintained that level of degradation over time, with increasing multiplicity of infection (MOI), and across modern influenza H1N1 and H3N2 strains. Chemical modifications to guides with potent LbuCas13a function, resulted in nebulizer delivered efficacy (>1-2 log reduction in viral titer) in a hamster model of influenza (Influenza A/H1N1/California/04/09) infection given prophylactically or as a treatment (post-infection). Maximum efficacy was achieved with two doses, when administered both pre- and post-infection. This work provides evidence that mRNA-encoded Cas13a can effectively mitigate Influenza A infections opening the door to the development of a programmable approach to treating multiple respiratory infections.

Confounding Factors in Targeted Degradation of Short-Lived Proteins.

Targeted protein degradation has recently emerged as a novel option in drug discovery. Natural protein half-life is expected to affect the efficacy of degrading agents, but to what extent it influences target protein degradation has not been systematically explored. Using simple mathematical modeling of protein degradation, we find that the natural half-life of a target protein has a dramatic effect on the level of protein degradation induced by a degrader agent which can pose significant hurdles to screening efforts. Moreover, we show that upon screening for degraders of short-lived proteins, agents that stall protein synthesis, such as GSPT1 degraders and generally cytotoxic compounds, deceptively appear as protein-degrading agents. This is exemplified by the disappearance of short-lived proteins such as MCL1 and MDM2 upon GSPT1 degradation and upon treatment with cytotoxic agents such as doxorubicin. These findings have implications for target selection as well as for the type of control experiments required to conclude that a novel agent works as a bona fide targeted protein degrader.

Distribution Profile of Benthic Macroinvertebrates in Some Rivers of Yaoundé City and Its Surroundings Using Self Organizing Map and Indicator value methods

Urban sprawl leads to the degradation of aquatic environments and, consequently, to the destruction of biodiversity. With the aim of highlighting the distribution profile of benthic macroinvertebrates in the city of Yaoundé and its surroundings according to the level of degradation, this study was carried out in seven rivers. A total of 144 taxa of benthic macroinvertebrates, belonging to 74 families, 15 orders, five classes, and three phyla, were collected from seven rivers in urban, peri-urban, and forest environments on Yaoundé and its surroundings. The self-organizing map (SOM) analysis tool was used to group the collected taxa from all stations into three clusters or affinity cores. The indicator value analysis (IndVal) method was employed to determine, based on their ecological preferences, which organisms were most likely to belong to each group. Out of the 144 collected taxa, only 44 were indicated to represent the three different groups. Thus, three communities were defined: the Hydropsyche community, with Hydropsyche sp. as the predominant taxon in Group III, characterizing well-oxygenated and low-mineralized stations; the Hydrocyrius community, where the species Hydrocyrius sp. predominates in Group I, describing stations with low oxygenation and moderate mineralization; and the Lumbriculidae community, where Lumbriculidae is the taxon associated with environments with high mineralization and critical oxygenation. These two methods contribute to the biomonitoring of tropical aquatic environments, firstly by grouping organisms by affinity and then identifying those that reflect the environment conditions. This facilitates the detection of changes in the quality of hydrosystems and guides management and conservation efforts.

Exercise Attenuate Diaphragm Atrophy in COPD Mice via Inhibiting the RhoA/ROCK Signaling.

Exercise is an indispensable component of pulmonary rehabilitation with strong anti-inflammatory effects. However, the mechanisms by which exercise prevents diaphragmatic atrophy in COPD (chronic obstructive pulmonary disease) remain unclear. Forty male C57BL/6 mice were assigned to the control (n=16) and smoke (n=24) groups. Mice in the smoke group were exposed to the cigarette smoke (CS) for six months. They were then divided into model and exercise training groups for 2 months. Histological changes were observed in lung and diaphragms. Subsequently, agonist U46639 and antagonist Y27632 of RhoA/ROCK were subjected to mechanical stretching in LPS-treated C2C12 myoblasts. The expression levels of Atrogin-1, MuRF-1, MyoD, Myf5, IL-1β, TNF-α, and RhoA/ROCK were determined by Western blotting. Diaphragmatic atrophy and increased RhoA/ROCK expression were observed in COPD mice. Exercise training attenuated diaphragmatic atrophy, decreased the expression of MuRF-1, and increased MyoD expression in COPD diaphragms. Exercise also affects the upregulation of RhoA/ROCK and inflammation-related proteins. In in vitro experiments with C2C12 myoblasts, LPS remarkably increased the level of inflammation and protein degradation, whereas Y27632 or combined with mechanical stretching prevented this phenomenon considerably. RhoA/ROCK plays an important role in the prevention of diaphragmatic atrophy in COPD.

Characteristics of unilateral and bilateral bovine twin foetuses

AbstractTwin pregnancy in cattle is undesirable for a number of reasons, including a higher abortion risk compared to pregnancies with a single foetus. Yet, the abortion risk is significantly influenced by the intrauterine location of the foetuses, that is, the abortion risk is several times higher if they are implanted in the same uterine horn (unilateral twin pregnancy) than if they are implanted with one foetus in each uterine horn (bilateral twin pregnancy). The reason for the higher abortion risk in unilateral twin pregnancies is unknown, but it may be related to malnutrition of the outermost foetus due to a limited placental capacity, as is the case for equine twin foetuses. A slaughterhouse study was performed and the foetuses of cattle pregnant with twins were measured. We identified 65 cases of twin pregnancies, of which 35 were unilateral twin pregnancies and 30 were bilateral twin pregnancies. There was no significant difference between the outermost and the more centrally located foetus in unilateral twin pregnancies in terms of body weight and length of the metacarpal diaphysis. Growth retardation of the outermost foetus could therefore not be confirmed as the cause of the higher abortion risk in unilateral bovine twin pregnancies. Four cases of pre‐slaughter foetal mortality were identified. In three of these cases, both twins were dead, of equal size and at a comparable level of degradation. In the fourth case, with approximately 40‐day‐old twin foetuses of equal size, only one of the foetuses showed signs of pre‐slaughter death.

Degradation of moxifloxacin hydrochloride encapsulated in halloysite nanotubes under the influence of temperature and ultraviolet and visible light

The photosensitive pharmaceutical ingredient moxifloxacin hydrochloride degrades during storage under the influence of external factors, such as elevated temperature and ultraviolet and visible light irradiation, resulting in a decrease in the concentration of the active substance. To increase its resistance to these external factors, moxifloxacin hydrochloride was encapsulated in halloysite nanotubes. The aim of this study was to determine the level of degradation of moxifloxacin hydrochloride in its native and encapsulated states under the influence of temperature and ultraviolet and visible light irradiation. Encapsulation was carried out by the vacuum method and confirmed by TEM microscopy. The residual content of the photosensitive pharmaceutical ingredient after degradation was monitored by high-performance liquid chromatography of a model solution with an initial concentration of 2 mg/ml, prepared from samples of native and encapsulated moxifloxacin hydrochloride previously tested under the influence of temperature and light irradiation. Encapsulated moxifloxacin hydrochloride showed increased resistance to degradation caused by visible light irradiation at 200 watt-hours/m2 (by 10.9%); resistance to degradation was increased by 13.4% and 14% under test conditions during 24 hours of ultraviolet light irradiation and thermostating at a temperature of 600C, respectively, compared to non-encapsulated moxifloxacin hydrochloride.

Correlation analysis of degrading systems based on bivariate Wiener processes under imperfect maintenance

AbstractThis article focuses on the correlation between the degradation levels of the two components that form a system. The degradation evolution of each component is modeled using Wiener processes. Both components are dependent and this dependence is described using the trivariate reduction method. To reduce the degradation and extend the system lifetime, preventive maintenance actions are periodically performed. These preventive maintenance actions are imperfect and they are modeled by using an arithmetic reduction of degradation of infinite order model with a determined maintenance efficiency parameter. The evolution of the maintained system is analysed by assessing the expectation and variance of both degradation processes at successive maintenance times. The novelty of this work is the analysis of the Pearson correlation coefficient between the degradation levels of the two components. Different properties of the monotonicity of the Pearson correlation coefficient between the two degradation paths are obtained by considering equal maintenance efficiency and equal general time scales functions for the two Wiener degradation processes associated to each degrading component.

Development of a Biodegradable Ternary Blend of Poly(vinyl alcohol) and Polyhydroxybutyrate Functionalized with Triacetin for Agricultural Mulch Applications.

The development of biodegradable mulch for agricultural applications represents a sustainable approach to reducing plastic pollution. Poly(vinyl alcohol) (PVA) is one of the nontoxic and biodegradable polymers that can be used as mulching film. However, a major drawback of PVA is its moisture sensitivity, which limits its applications. In this study, a biocomposite based on PVA and polyhydroxybutyrate (PHB), plasticized with triacetin, was developed by solvent casting method. The biocomposite film exhibited good mechanical properties, better integrity, reduced transmittance, and light-blocking properties, which can prevent weed growth. Additionally, an improvement in surface characteristics was observed, as demonstrated by the shift in contact angle from 44 to 99° and a reduction in the water vapor transmission rate (WVTR) from 4.82 to 2.31 g/h m2. For agronomic application, the developed films were experimentally applied as mulch for maize plants in pots. The results were positive, showing that the mulches effectively supported the growth of the maize plants. Further, signs of initial degradation were observed after 5 days, and the film reached a degradation level of 50-55% after 30 days under natural conditions. Thus, this work has provided new insights for expanding the application range of PVA films in biobased mulching materials.

Study on the Degradation Pattern of Impact Crater Populations in Yutu-2′s Rovering Area

A detailed analysis of the panoramic camera data from the 27th to 33rd lunar days was conducted on the high-resolution scenes captured by the Yutu-2 rover stations. This analysis aimed to determine the detailed morphological parameters of the 2015 impact craters within the inspection area. The levels of degradation observed in the impact craters were determined alongside the surface features. Subsequently, the degradation patterns of the impact craters located within the Yutu-2’s roving area and the distribution patterns of the morphological parameters were analysed and investigated. The results of the analysis indicate that 94% of the impact craters exhibited severe degradation, 80% had depth-to-diameter ratios (DDRs) ranging from 0.07 to 0.17, and the remaining craters were moderately degraded. The DDRs of the impact craters exhibited a declining trend with an increase in the dimensions of the impact craters. Additionally, the degree of degradation of impact crater populations demonstrated a decreasing trend. In general, the impact craters along the rover’s route exhibited severe degradation, with the population of degradation degrees gradually decreasing with increasing diameter.

Land Degradation Affects Soil Microbial Properties, Organic Matter Composition, and Maize Yield

Land degradation severely affects soil functions, thereby weakening crop productivity. However, the quantitative effects of the soil organic matter (SOM) composition and soil microbial properties on maize yield remain unclear under different levels of land degradation. Here, a gradient of land degradation was selected for sampling in the Horqin Sandy Land in northeast China. The results show that the relative abundances of aliphatic and aromatic groups decreased by 21.51% and 86.01% with increasing land degradation, respectively, and the considerable increase in polysaccharide groups led to a decrease in stability and resistance to SOM decomposition. Microbial properties, such as microbial biomass carbon, basic respiration, qCO2, and enzyme activities, decreased as a result of land degradation. The phospholipid fatty acid content and the ratio between bacteria and fungi markedly decreased with an increasing level of land degradation, and the ratio of G+ to G− markedly increased. Correlation analysis confirmed that the microbial properties were significantly related to the SOM composition, and the random forest model indicated that fungi were key factors affecting maize yield (7.15%, p < 0.05). Moreover, the results of the structure equation modelling revealed that land degradation reduced the soil physiochemical properties, resulting in a decrease in microorganisms, causing variations in the SOM composition and directly leading to a decrease in crop yield. The effect of microorganisms (β = 0.84 ***) on maize yield was greater than that of the SOM composition (β = 0.53 **). Our investigation can provide a theoretical basis for the conservation of the cropland in Horqin Sandy Land.

Selenium and its nanoparticles modulate the metabolism of reactive oxygen species and morpho-physiology of wheat (Triticum aestivum L.) to combat oxidative stress under water deficit conditions

BackgroundWheat (Triticum aestivum L.) is one of the most important cereal crop species worldwide, but its growth and development are adversely influenced by drought stress. However, the application of trace elements is known to improve plant physiology under water-limited conditions. In this study, the effects of drought stress on wheat plants were investigated, with a focus on potential mitigation by foliar application of selenium nanoparticles (Se(np)) and sodium selenate (Na2SeO4). The experiment was conducted in a net house using a completely randomized design with four replications. The treatments involved three levels of drought stress (mild, moderate, and severe) started at 30 days after sowing (DAS), with foliar sprays of Se(np) and Se (both 25 µM) initiated at 27 DAS and repeated 4 times at 7-day intervals until 55 DAS.ResultsDrought stress significantly reduced plant growth, whereas Se(np) and Se sprays enhanced it. Drought stress induced chlorophyll degradation, increased malondialdehyde and hydrogen peroxide levels, impaired membrane stability, and caused electrolyte leakage. Severe drought stress reduced the levels of antioxidants (e.g., proline, ascorbate, and glutathione by 4.18-fold, 80%, and 45%) and the activities of antioxidant enzymes (ascorbate peroxidase, dehydroascorbate reductase, and others). Conversely, treatment with Se(np) and Se restored these parameters, for example, 1.23-fold higher total chlorophyll content with Se(np) treatment, 26% higher APX activity with Se treatment, 15% lower electrolyte leakage with Se treatment in wheat plants under severe drought stress. This Se-associated enhancement facilitated rapid scavenging of reactive oxygen species and reduced methylglyoxal toxicity, thereby diminishing oxidative stress and positively affecting the morphophysiological and biochemical responses of the plants under drought.ConclusionsDrought-stressed wheat plants exhibited reductions in physiological processes, including water uptake and photosynthetic activity. However, Se(np) and Se applied at 25 µM mitigated the detrimental effects of drought. The application of Se(np) was notably more effective than the application of Se in mitigating drought stress, indicating the potential of the application of Se(np) as a sustainable agricultural practice under water-limited conditions.

Impact of Urbanization Processes on Vegetation Cover in the Cities Over the Last Two Decades

Background: The process of urbanization serves as a prominent factor leading to the vegetation cover decline in major cities worldwide. This issue has significant consequences for the living environment on a global scale. Methods: Leveraging the latest advancements in remote sensing techniques (RSTs) and utilizing high-resolution satellite imagery, this study aims to assess the vegetation cover alteration (VCA) in correlation with the urbanization process in Thai Nguyen City, Vietnam. Landsat 5 TM and Sentinel 2A satellite imagery were used to analyze the VCA in Thai Nguyen City during the period from 2001 to 2023. Thai Nguyen city is recognized as the third largest in Northern Vietnam, following the capital city of Hanoi and Hai Phong City and ranks as the tenth most populous city in Vietnam. Result: The results obtained from this study demonstrate a substantial overall expansion, with the total urban land increasing from 386 hectares in 2001 to 1045 hectares in 2010 and experiencing a rapid surge in 2023, reaching a remarkable 4409 hectares. In general, analyzed results based on VCA maps indicated an overall vegetation cover reduction across the study area. This indicates that the study area has reached a critically high level of degradation in terms of vegetation cover. These findings emphasize the escalating risks associated with the diminishing vegetation cover detected across the study area.

Universal Image Restoration with Text Prompt Diffusion.

Universal image restoration (UIR) aims to accurately restore images with a variety of unknown degradation types and levels. Existing methods, including both learning-based and prior-based approaches, heavily rely on low-quality image features. However, it is challenging to extract degradation information from diverse low-quality images, which limits model performance. Furthermore, UIR necessitates the recovery of images with diverse and complex types of degradation. Inaccurate estimations further decrease restoration performance, resulting in suboptimal recovery outcomes. To enhance UIR performance, a viable approach is to introduce additional priors. The current UIR methods have problems such as poor enhancement effect and low universality. To address this issue, we propose an effective framework based on a diffusion model (DM) for universal image restoration, dubbed ETDiffIR. Inspired by the remarkable performance of text prompts in the field of image generation, we employ text prompts to improve the restoration of degraded images. This framework utilizes a text prompt corresponding to the low-quality image to assist the diffusion model in restoring the image. Specifically, a novel text-image fusion block is proposed by combining the CLIP text encoder and the DA-CLIP image controller, which integrates text prompt encoding and degradation type encoding into time step encoding. Moreover, to reduce the computational cost of the denoising UNet in the diffusion model, we develop an efficient restoration U-shaped network (ERUNet) to achieve favorable noise prediction performance via depthwise convolution and pointwise convolution. We evaluate the proposed method on image dehazing, deraining, and denoising tasks. The experimental results indicate the superiority of our proposed algorithm.

Impact of LiDAR point cloud compression on 3D object detection evaluated on the KITTI dataset

The rapid growth on the amount of generated 3D data, particularly in the form of Light Detection And Ranging (LiDAR) point clouds (PCs), poses very significant challenges in terms of data storage, transmission, and processing. Point cloud (PC) representation of 3D visual information has shown to be a very flexible format with many applications ranging from multimedia immersive communication to machine vision tasks in the robotics and autonomous driving domains. In this paper, we investigate the performance of four reference 3D object detection techniques, when the input PCs are compressed with varying levels of degradation. Compression is performed using two MPEG standard coders based on 2D projections and octree decomposition, as well as two coding methods based on Deep Learning (DL). For the DL coding methods, we used a Joint Photographic Experts Group (JPEG) reference PC coder, that we adapted to accept LiDAR PCs in both Cartesian and cylindrical coordinate systems. The detection performance of the four reference 3D object detection methods was evaluated using both pre-trained models and models specifically trained using degraded PCs reconstructed from compressed representations. It is shown that LiDAR PCs can be compressed down to 6 bits per point with no significant degradation on the object detection precision. Furthermore, employing specifically trained detection models improves the detection capabilities even at compression rates as low as 2 bits per point. These results show that LiDAR PCs can be coded to enable efficient storage and transmission, without significant object detection performance loss.

Elevating Recycling Standards: Global Requirements for Plastic Traceability and Quality Testing

Globally, we produced 489 million tonnes of plastic in 2023 and we recycled only 8.17%. This study navigates the landscape of recycling practices, highlighting the imperative to reevaluate and upgrade industry-standard protocols. The central focus of this study is on integrating more robust traceability criteria and advanced quality testing methodologies to improve recycled plastics with intrinsic value, particularly in anticipation of future market applications. The investigation examines the prevailing industry standard traceability and quality framework. It then assesses the applicability of those standards using technical datasheets for recycled high-density polyethylene resin grades. This study proposes a paradigm shift toward a more sophisticated analytical approach. This comprehensive framework aims to transcend traditional quality and traceability evaluation. This paper employs a mixed methodological approach, including a thematic analysis of relevant industry standard regulations and an in-depth literature review, to address the need for an operational framework for recycling quality. This study highlights that recycling quality depends on technical attributes determining functionality and application suitability. While some properties are measured, the conventional framework does not address the degradation level of recycled plastic. This study concludes with broader considerations, emphasising the need for a traceability model to disclose material history and composition. This study advocates an industry-wide upgrade in recycling standards, prioritising traceability and quality testing. The proposed enhancements in testing grids and the improved understanding of recycling quality collectively contribute to a holistic framework, unlocking the intrinsic value of recycled plastics for future market applications.

Study on the effect of rubber content on the frost resistance of steel fiber reinforced rubber concrete

In cold areas, the steel fiber reinforced rubber concrete (SFRRC) pavement is exposed to natural environment and experiences varying degrees of damage from freezing and thawing. This can have a serious impact on the normal usage and safe operation of the pavement structure. This research examines the impact of varying rubber concentrations on multiple variables, such as the rate of mass reduction, relative dynamic modulus of elasticity, compressive strength, and thickness of the damage layer (Hf) during freeze–thaw (F-T) durability testing conducted on SFRRC. Furthermore, an analysis is conducted to determine the degradation pattern exhibited by SFRRC. The internal structure evolution and pore structure characteristics of SFRRC were examined using scanning electron microscopy and mercury intrusion porosimetry techniques, which revealed the underlying damage mechanism in SFRRC during F-T cycles. The results suggest that the addition of an appropriate amount of rubber can effectively enhance the frost resistance of SFRRC in water. A gradual improvement in the frost resistance of SFRRC is observed when increasing the rubber content from 0 to 10%. The optimal frost resistance is observed in SFRRC with 10% rubber content. However, when the rubber content reaches 15%, SFRRC exhibits significant degradation and lower level of resistance to freezing compared to SFRRC without rubber. Microcracks form within SFRRC due to the freezing–thawing forces experienced during the experiment, resulting in the development of a damage layer that extends from the surface to the interior. The compressive strength of the damaged layer significantly decreases as Hf increases. The addition of appropriate rubber in SFRRC improves its pore structure, leading to an increased proportion of harmless or less harmful pores and a reduction in average pore size, thereby significantly enhancing its frost resistance.

Streamlining biological recycling of poly(ethylene terephthalate) via pre-treatment methods

In this study, we validated various methods of pre-treatment of poly(ethylene terephthalate) (PET) by the engineered yeast Yarrowia lipolytica. This research compares both the effect of the type of plastic used, the processing method and enzymes with different mechanisms of action (PETase and cutinase). The investigation demonstrated that the degradation efficiency varies depending on the type of plastic used, the processing methods and the applied enzyme. Moreover, it indicated that during prolonged yeast culture under the applied conditions, enzyme activity is not impaired. Among all the methods tested, the artificial aging process had the greatest impact on the degradation level by PETase, where the amount of TPA released from commercial PET film was the highest, and yielded over 2 gL-1. The maximum yield of TPA (0.59 gL-1), for the Y. lipolytica strain overexpressing cutinase, was observed during the process with recycled PET bottles shredded into 1 mm fragments. The maximum recorded weight loss of plastic film is over 70% for commercial PET film subjected to artificial ageing process.

Advances in the Use of Four Synthetic Antioxidants as Food Additives for Enhancing the Oxidative Stability of Refined Sunflower Oil (Helianthus annuus L.)

The present investigation was performed to evaluate the effects of various synthetic antioxidants (vitamin A, vitamin E, β-carotene, and BHT) on the oxidation of sunflower oil subjected to accelerated thermal storage at 60 °C for three months (12 weeks). The performance of the antioxidants studied was evaluated using several quality parameters: the free fatty acid value (FFA), primary oxidation (via the peroxide value (PV) and K232 value), secondary oxidation products (via the anisidine value (p-AV) and K270 value), and the total oxidation value (TOTOX). The fatty acid composition (FAC), oxidizability value (COX), iodine value (IV), and pigment content (chlorophyll and carotenoid) were also evaluated. The results revealed that the control sample of sunflower oil exhibited higher susceptibility to oxidative deterioration. Antioxidants at 200 ppm were more effective in preserving the oxidative stability of sunflower oil subjected to accelerated storage compared to the control oil. The smallest increases in all stability parameter indexes were recorded for antioxidant-supplemented sunflower oil. However, the IV and chlorophyll and carotenoid contents were reduced. At 200 ppm, vitamin E and β-carotene showed the greatest stability in sunflower oil, while their combination with vitamin A at 100 ppm of each showed the lowest stability. In addition, synthetic antioxidants provided greater protection against the degradation of polyunsaturated fatty acids (PUFAs). The highest level of PUFA degradation was recorded in the control oil, followed by the oil containing vitamin A. In conclusion, adding synthetic antioxidants to sunflower oil improves its stability during storage. However, some authors associated these molecules with a health risk due to carcinogenic effects as these molecules have been listed as “Generally Recognized As Safe” (GRAS).