Color Degradation Research Articles

Effect of Pulsed Electric Fields and Osmotic Dehydration on the Quality of Modified-Atmosphere-Packaged Fresh-Cut and Fried Potatoes

The aim of this research was to study the effect of osmotic dehydration (OD) and/or pulsed electric field (PEF) on the quality of MAP-packed potatoes, both as raw materials and after deep frying. Fresh-cut potato strips (from Naxos island) were osmotically dehydrated using a solution of 20% glycerol, 5% sodium chloride, and 1% ascorbic acid (wt) at a 5:1 liquid-to-food ratio at 35 °C for 120 min. OD-treated and untreated samples were packaged at MAP (0.2% O2 + 12% CO2) and stored at 4, 8, and 12 °C. Color (Browning Index, BI), texture (hardness, Fmax), sensory characteristics (including total sensory quality), and microbial stability (total aerobic and anaerobic counts, Pseudomonas, Entrobacteriaceae, and yeasts/molds) were monitored during storage. After package opening, samples were deep-fried at 180 °C for up to 8 min, and the oil content of fried samples was quantified. Sensory evaluation of raw and fried samples was conducted. Untreated fresh-cut potatoes were characterized by detrimental color degradation starting from the third day of storage at 4 °C and presented microbial growth (total viable counts: 6 log (CFU)/g) on the sixth day, whereas pre-treated potato samples retained their color and microbiological stability after 15 and 18 days of cold storage, respectively. OD pre-treatment reduced the oil uptake during frying (up to 30%).

A color comparison between inkjet and dye sublimation on non-paper substrates after environmental exposure

This study originated with a need to achieve archival quality for full color, fine art photography and art when printed on non-traditional substrates. In order to better understand how environmental factors affect color fastness and accuracy across two common photo production processes–dye sublimation and inkjet–the authors compared color shifts on targets printed on glass, metal, tile, and wood after exposure to humidity or full spectrum UV light. After coating and printing on the substrates, a spectrophotometer was used to record pre-exposure LAB readings from the printed targets. Post-exposure readings were recorded using the same device after each sample was exposed to 500 consecutive hours of either humidity or UV light. A regression analysis and paired T-tests were used to analyze the shift in color after environmental exposure across substrates and printing processes. Before environmental exposure, the authors found that dye sublimation, especially on metal substrates, produced visually richer colors compared with the inkjet process. This observation was confirmed quantitatively when all substrates printed with inkjet produced lower average densities than those printed using dye sublimation, with wood and metal having overall higher color densities than glass and tile. With regards to substrate performance, tile printed with either process performed similarly across both environmental conditions with minimal degradation during exposure. Dye sublimated wood under UV and inkjet-printed metal exposed to humidity degraded the most significantly across all the variable combinations. The authors concluded that even though some process and substrate combinations perform better than others, exposure to certain environmental factors can lead to significant color degradation and therefore, fine art prints should be protected to ensure longevity when there is an expected environmental condition. However, an artist or collector can choose substrate and print process combinations that are more likely to withstand environmental conditions yet still provide the intended visual impact.

Optimizing Ti/RuO2-IrO2 – electro activated persulfate oxidation processes for the degradation of ammonia-nitrogen and color from landfill leachate using Response Surface Methodology

Landfilling disposal method has raised many environmental concerns especially water pollution from the discharge of landfill leachate. This study is aimed at investigating degradation of ammonia and removal of color of landfill leachate by electro-persulfate activation using rutheniumiridium coated titanium (Ti-RuO2/IrO2) electrode. Process variables such as reaction time, current density and persulfate dosage were optimized using central composite design via response surface methodology (RSM). RSM models show high coefficient of determination, R2 of 0.9182 and 0.9249 for ammonia-nitrogen (NH3-N) and color respectively. The maximum removal efficiency for NH3-N and color were recorded as 83.7% and 65.8% respectively. Persulfate can be used in oxidation processes as an activating agent to remove NH3-N and color from landfill leachate.

Influence of edible flowers on the physicochemical and oxidative stability of raw ground beef patties

This study investigates the antioxidant and physicochemical characteristics of raw ground beef patties and raw ground beef patties treated with varying percentages of roselle (Hibiscus sabdariffa L.) and rose (Rosa canina L.) powders during 7 days of storage at 4°C. The analysis included key parameters such as antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, lipid oxidation through 2-thiobarbituric acid reactive substances (TBARS), protein oxidation markers (carbonyls, Schiff bases, and free thiols), water-holding capacity, pH, color, and texture. Both roselle and rose powders enhanced the antioxidant capacity of the patties, reducing oxidative markers (TBARS, carbonyls, Schiff bases, and free thiols) during storage. Additionally, improved water-holding capacity and reduced pH were observed across all treated patties, with minimal impact on texture. However, while roselle powder showed beneficial effects, patties treated with rose powder exhibited superior overall results. The more favorable outcomes in rose-treated patties, particularly in oxidative stability and physicochemical properties, can be attributed to the higher concentrations of bioactive compounds, such as phenolic acids and flavonoids, present in rose powder. These compounds likely contributed to enhanced free radical scavenging activity, providing stronger protection against lipid and protein oxidation. Furthermore, rose powder maintained more stable color and physicochemical properties, with patties showing acceptable color and minimal texture degradation by the 7th day of storage. These findings highlight the potential of rose powder as a highly effective natural additive for extending the shelf life and preserving the quality of ground beef patties, positioning it as a promising ingredient for future applications in the food industry.

Influence of Soaking and Sprouting on the Colour Kinetics of White Sorghum Grains

Colour is a critical sensory quality parameter reflecting the final quality of various food grain products. This study investigated the impact of different soaking durations (6, 12, 18, and 24 hours) and sprouting periods (24, 36, 48, 60, and 72 hours) on the color degradation kinetics of white sorghum grains. Colour parameters such as lightness (L*), redness/greenness (a*), yellowness/blueness (b*), total colour change (ΔE), and browning index (BI) were measured. These experimental values were fitted to four selected models (Zero-order, First-order, Power, and Quadratic) using MATLAB R2019a’s non-linear regression tools. Comparing the soaked and sprouted samples, the soaked grains exhibited superior colour characteristics, with higher lightness values that are favourable for milling, whereas the sprouted samples showed increased redness and browning index values. The results indicated that the Quadratic equation best described the color changes in both soaked and sprouted sorghum samples.

Stain-free SDS-PAGE for deciphering the structural stability, degradation and aggregation of Colorant-Phyco-Cyanin subunits during thermoprocessing of gummy candy

Gummy candy is one of the most popular confectionery products, and their high consumption raises some concerns due to their low nutritional value and high sugar content. In this study, fructose as a low glycemic sugar was partially replaced with sucrose, then the color/antioxidative stability of natural Colorant-Phyco-Cyanin added at varied temperature to gummy solution was evaluated. The experiment was designed based on two treatment groups consisting sucrose + glucose syrup (S treatments: S37, S47, S57, S67) and the partial substitution of sucrose with fructose syrup (F treatments: F37, F47, F57, F67). Blue color degradation was minimal in F37/F47, which exhibited visual appeal while sucrose samples showed discoloration. The antioxidative values differed by ten/twelve orders of magnitude in the C-PC added gummy candies. Noteworthy, this study presents the first attempt to elucidate C-PC subunits on the free-stained transparent SDS-PAGE during thermo-processing of the gummy solution. C-PC from F37 revealed sharp bands of α/β subunits responsible for appealing blue hue, yet phycocyanin from S67 exhibited faded subunits along with an additional band of hexameric αβ aggregate, responsible for cyan tone. These results illustrate the potential for partially replacing sucrose with fructose as stabilizer of C-PC in the production of antioxidant-rich and visually appealing gummy candies, offering an alternative to commonly used colorants.

In Operando Optical Analysis of Electrolyte Colour Change and Its Correlation to Capacity Fade in Li-Ion Cells at Elevated Temperatures.

The existing body of research on battery state of health has identified various degradation modes for the electrolyte, yet very few studies have explored the role of electrolyte colour changes as a diagnostic tool for state of health (SOH). This study investigates the impact of elevated temperatures and its correlation with electrolyte colour changes and capacity fade during cycling. Specifically, the research examines whether cycling cells at elevated temperatures induces noticeable changes in electrolyte colour and whether these changes can be linked to the SOH of the cells. The methodology employs in operando optical sensors to monitor real-time colour shifts in the electrolyte, aiming to demonstrate a qualitative relationship between electrolyte colour change, degradation, thermal ageing, and capacity fade, laying the foundations for future quantitative assessment of the relationships identified. Our research builds upon these findings by offering a novel approach that integrates optical sensing to provide real-time visual evidence of electrolyte degradation and colour change during cell operation. The results demonstrate a clear relationship between elevated temperature, electrolyte colour change, and capacity fade, leading to accelerated degradation. This approach offers a new insight over traditional in exitu battery diagnostics, as it enables continuous in operando monitoring of electrolyte colour change and has the potential to unlock a detailed understanding of the chemical reactions and electrolyte breakdown during cycling.

Decolorization Kinetics of Organic Pollutant Dye Compounds from Wastewater

The removal of colored-toxic materials from industrial wastewater has been subject to investigations since years. There are more than several methods to overcome these problems. In this article, sodium sulfite as a scavenger was used to remove the color of basic red 46 and methylene blue in solution as model pollutant materials in water. Color removal kinetics was studied by using sodium sulfite amount, pH of the solution, time and temperature as parameters. The effect of these parameters was reported according to the decay kinetics of absorbance of the dye compounds in solution by using molecular absorption spectroscopy. It observed that the color degradation of basic red 46 obeys bi-exponential decay whereas methylene blue obeys single exponential decay. The kinetic rate constants were determined from fit of the absorbance decay studies and temperature dependence of process was discussed with Arrhenius equation.

Underwater image quality enhancement using fusion of adaptive colour correction and improved contrast enhancement strategy

ABSTRACT Underwater images suffer from poor visibility due to low contrast, colour degradation, and noise, making them unsuitable for several visual tasks. While significant progress has been made recently in enhancing underwater images, achieving robust improvements remains a challenge. To address these issues, a new two-step framework combining adaptive colour correction and an improved local and global contrast enhancement algorithm are proposed to improve the quality of underwater images significantly. First, an adaptive colour correction strategy to compensate for degraded colour channels according to compensation factors for restoring the balance in the damaged colour channels is developed. Secondly, an improved contrast enhancement algorithm is presented to enhance the local and global contrast of underwater image and to sharpen the textural details. Finally, these two output images are fused together using principal component analysis (PCA) fusion. Experiments conducted on the established benchmarks for underwater image enhancement, namely the UIEB and EUVP datasets, have demonstrated the capability of the proposed algorithm to produce images of superior quality in terms of qualitative and quantitative performance measures compared to the latest state-of-the-art methods.

Native microorganisms for sustainable dye biodegradation in wastewaters from jeans finishing.

The textile mill is one of the most water-consuming industries. Wastewater production is very high, and among the main generated pollutants are dyes. In particular, jeans finishing, which is performed all over the world, generates wastewater with indigo dye that has to be eliminated before discharge. This work studies the biological treatment of this type of wastewater using native microorganisms, i.e., without the need for external seed sludge to start-up the process. Two strategies for starting up the biological treatment using laboratory sequencing batch reactors have been compared: the addition of seed sludge from a biological reactor of a wastewater treatment plant and the non-addition of seed sludge, which means that native microorganisms (those in wastewater coming from the industry facilities) are responsible for COD and color degradation. Special attention is paid to biomass shift in both reactors, analyzing both bacterial and fungal populations. Results yielded more than 90% of COD and color removal after 25days in both reactors. MLSS increased in both reactors during the operation, reaching very similar values (around 1840mg/L). Rozellomycota was the predominant phylum in the reactors. Concerning bacteria, Planctomycetota abundance increased considerably in both reactors, which shows the important role of these bacteria in the treatment. It can be concluded that the lower bacterial diversity in the native population in comparison with the seeded sludge was shifting to a higher microbial diversity during the process, achieving a similar microbial population in reactors. It implies that it is not necessary to either work with isolated cultures or seeded sludge, which leads to a simpler and more sustainable solution for textile wastewater treatment in areas all over the world.

Effect of Various Carbohydrates in Aqueous Solutions on Color Stability and Degradation Kinetics of Selected Anthocyanins During Storage.

Anthocyanins are flavonoid substances of plant origin with potential antioxidant effects. Because of their intense colors, they are used as natural dyes in food. However, their stability in food matrices is limited. This study aimed to verify the effect of selected carbohydrates on the stability of anthocyanins (cyanidin-3-O-β-glucopyranoside, cyanidin-3-O-β-galactopyranoside, cyanidin-3-O-β-rutinoside and delphinidin-3-O-β-rutinoside) during the accelerated storage test, since carbohydrates help to preserve the typical color of anthocyanins, increase their shelf-life and availability in the organism, and reduce losses during processing. Moreover, the kinetic parameters of anthocyanin degradation (Ea, k, t1/2) were determined. Sucrose was found to have the greatest potential for retarding anthocyanin degradation during storage, whereas fructose exerted an accelerating effect. Glycosidation of anthocyanin aglycone had no significant effect in terms of their stability. Anthocyanin degradation was significantly positively correlated with the change in the a* parameter (redness), and subsequently, a significant positive correlation was observed in the determination of the kinetic parameters for anthocyanins and the a* parameter. The highest stability of anthocyanins was observed in the presence of sucrose and their degradation can be predicted by the value of the a* parameter, which would also be a very fast and non-destructive method for food processing companies.

Randomizing polarization of displays for fundamental improvement of color mura caused by birefringence.

Most existing displays utilize polarization technologies to produce images and improve image quality. However, polarized light from displays causes color mura because of the birefringence of the polymer films used. Thus, eliminating color degradation remains a challenge despite the incorporation of complex polarization technologies such as retardation films. Our proposed random depolarization film (RDF) addresses this issue by randomizing the polarization of light from displays. Chromaticity measurements demonstrate that the RDF effectively compensates for color mura due to low-cost polymer films. Notably, the RDF compensation mechanism is independent of the RDF position and light source spectrum. Therefore, the RDF could be an innovative solution for color degradation in existing displays.

Fruit Extract Mediated Formation of Luminescent Titanium Dioxide Nanometer-Sized Particles: An Innovative Strategy in Domain of Photodecomposition and Germicidal Properties.

Discoveries in nanotechnologies are placing a great deal of attention on greener strategies that use harmless substances and moderated reactions to promote healthy development. This work used a straightforward, innovative, and cost-effective sustainable approach to produce bio-augmented TiO2 nanometer-sized particles (NMSP) by applying a water-based extract of the star fruit as a stabilization and reduction agent. A variety of techniques, comprising UV-Vis, XRD, FT-IR, FE-SEM with EDAX, and TEM, have been employed to investigate the formed TiO2 NMSP. The germicidal properties of formed TiO2 NMSP towards germs have been investigated by implementing an agar-based pore plate technique. Congo red and methylene blue dyes have been applied to assess photodecomposition activity. The TiO2 NMSP exhibited significant germicidal efficacy versus many pathogenic microbes. The maximum degradation percentages of Congo red and methylene blue were 89.2% and 83.7%, achieved after 60 and 70 min, respectively. Consequently, it is determined that the selected NMSP composition enhanced germicidal and photodecomposition capabilities. The combined effort may serve as an effective method for eliminating color degradation concerning effluent and could potentially be employed in the field of medicine to address antibiotic resistance.

Impact of magnetic field-assisted freezing on the physicochemical properties and starch structure of cooked rice: Effects of magnetic types, intensities, and cryostasis time

A magnetic field-assisted freezing system was developed to mitigate the degradation of taste quality in frozen cooked rice (FCR). The physicochemical properties and starch structure were analyzed under varying magnetic field types, intensities, and cryostasis time. The analysis of freezing characteristics indicated that treatments with 10 mT static magnetic fields (SMF) and 6 mT alternating magnetic fields (AMF) yielded optimal results, significantly reducing the duration of the maximum ice crystal generation zone by approximately 18 min. Compared to no magnetic field (NMF) treatment, a 16-day frozen storage experiment showed significant improvements in the texture characteristics of cooked rice treated with magnetic fields. However, the moisture content of rice treated with AMF closely resembled those of freshly cooked rice, with a slight increase in yellowness compared to SMF treatment. Throughout the storage period, the crystallinity for the AMF treatment exceeded that of the SMF treatment by 2.99 %. Furthermore, compared to SMF treatment, water molecules in FCR treated with AMF are more tightly bound. Given the superior sensory scores in the AMF treatment, it can be concluded that while SMF reduces color degradation, AMF is more effective in preserving moisture, and structural density. Hence, magnetic fields, especially AMF, emerge as a promising auxiliary technology for FCR, offering a theoretical basis for advancing cold chain logistics technology for cooked rice.

Multi exposure fusion for high dynamic range imaging via multi-channel gradient tensor

Multi-exposure fusion (MEF) is an effective technique for directly fusing a sequence of low dynamic range (LDR) images from a high dynamic range (HDR) natural scene. The goal is to generate an information enriched LDR image. Despite its effectiveness, current MEF methods often encounter issues such as detail loss and color degradation. Additionally, existing algorithms often struggle to balance image quality and computation time, particularly for large-sized images. This paper introduces an innovative MEF algorithm that address these challenges, offering improved performance and computational time across all image sizes. The algorithm employs a multi-channel gradient tensor on RGB images to effectively capture the contrast information among the three channels. This mechanism allows an edge-preserving image filter to maintain edges while smoothing weight maps. To enhance computational efficiency, the algorithm uses a fast approximation method suitable for large sized images. Our comprehensive experimental results demonstrate that the proposed method outperforms existing MEF techniques both quantitatively and qualitatively. Furthermore, our method reduces computational time by approximately 30% compared to the most recent state-of-the-art techniques.

Comparative Analysis of Shelf-Life, Antioxidant Activity, and Phytochemical Contents of Australian-Grown and Imported Dragon Fruit under Ambient Conditions

Dragon fruit (Hylocereus spp.), renowned for its aesthetic appeal and rich antioxidant content, has gained global popularity due to its numerous health benefits. In Australia, despite growing commercial interest in cultivating dragon fruit, there is uncertainty for local growers stemming from competition with imported varieties. Notably, there is a lack of comparative research on the shelf-life, antioxidant activity, and phytochemical contents of Australian-grown versus imported dragon fruit, which is crucial for enhancing market competitiveness and consumer perception. This study compares the shelf-life, antioxidant activity, and phytochemical content of Australian-grown and imported dragon fruits under ambient conditions, addressing the competitive challenges faced by local growers. Freshly harvested white-flesh (Hylocereus undatus) and red-flesh (H. polyrhizus) dragon fruit were sourced from Queensland and the Northern Territory and imported fruit were sourced from an importer in Queensland. All fruit were assessed for key quality parameters including peel color, firmness, weight loss, total soluble solids (TSS), pH, titratable acidity (TA), total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), total betalain content (TBC), and total anthocyanin content (TAC). The results indicate that Australian-grown white dragon fruits exhibited average one day longer shelf-life with less color degradation, better firmness retention, and less decline in weight loss, TSS, and acidity compared to imported fruits. Australian-grown red dragon fruits showed similar shelf-life compared to fruits from overseas. Antioxidant activities and phytochemicals were consistently higher in Australian-grown fruits throughout their shelf-life. These findings indicate that Australian-grown dragon fruits offer better physical quality and retain more nutritional value, which could enhance their marketability.

Shelf-life extension of pomegranate arils using banana powder-based nanocomposite coatings functionalized with cellulose nanofiber and zinc-oxide nanoparticles

ABSTRACT This study explored a novel nanocomposite comprising banana powder (BP), cellulose nanofiber (CNF), and 0.6% zinc oxide nanoparticles (ZnO NPs). The treatment involved immersing arils in the respective nanocomposite coatings for 4 min, followed by air-drying at room temperature (25°C) and subsequent storage in polyethylene terephthalate punnets at 4°C and 85% relative humidity for 21 d. Results demonstrated that the nanocomposites significantly (p < .05) reduced total plate and yeast counts, delayed colour and texture degradation, and decreased weight loss and respiration rates while maintaining levels of total soluble solids and titratable acidity compared to the control (water) and standard BP/CNF treatment. The BP/CNF/ZnO-PPW was more effective as it displayed a lower respiration rate (50 mL CO2 kg−1 h −1), weight loss (0.4%), and maintained higher firmness (12.4 N) compared to the control treatment. Overall, the nanocomposite treatments with ZnO NPs resulted in a 6-day shelf-life extension, offering a promising solution through nanotechnology applications.

Improved Detection of Multi-Class Bad Traffic Signs Using Ensemble and Test Time Augmentation Based on Yolov5 Models

Various factors such as natural disasters, vandalism, weather, and environmental conditions can affect the physical state of traffic signs. The proposed model aims to improve detection of traffic signs affected by partial occlusion as a result of overgrown vegetation, displaced signs (those knocked down, bent), perforated signs (those damaged with holes), faded signs (color degradation), rusted signs (corroded surface), and de-faced signs (placing graffiti, etc., by vandals). This research aims to improve the detection of bad traffic signs using three approaches. In the first approach, Spiral Pooling Pyramid-Fast (SPPF) and C3TR modules are introduced to the architecture of Yolov5 models. SPPF helps provide a multi-scale representation of the input feature map by pooling at different scales, which is useful in improving the quality of feature maps and detecting bad traffic signs of various sizes and perspectives. The C3TR module uses convolutional layers to enhance local feature extraction and transformers to boost understanding of the global context. Secondly, we use predictions of Yolov5 as base models to implement a mean ensemble to improve performance. Thirdly, test time augmentation (TTA) is applied at test time by using scaling and flipping to improve accuracy. Some signs are generated using stable diffusion techniques to augment certain classes. We test the proposed models on the CCTSDB2021, TT100K, GTSDB, and GTSRD datasets to ensure generalization and use k-fold cross-validation to further evaluate the performance of the models. The proposed models outperform other state-of-the-art models in comparison.

Effect of selective preservatives on shelf-life of guava juice extracted using pectinase enzyme

The study investigated the feasibility of enzymatic extraction for guava juice and evaluated the effects of various preservatives on its shelf life. The crushed guava puree was undergone different pectinase enzyme concentrations over three incubation periods. The findings revealed that pectinase concentrations of 0.1 % and 0.2 %, when incubated for 1 and 2 h, were the most effective. Juice yields ranged from 65.24 % to 78.64 %, with Total Soluble Solids (TSS) varying from 9.12°Brix to 11.56°Brix. The physicochemical properties of the guava juice resulted 84.2 % moisture, 2.16 % protein, 0.77 % fat, 3.27 % fiber, 0.65 % acidity, 2.25 % reducing sugars, 8.27 % non-reducing sugars, 79.53 % antioxidant activity, 173.2 mg/100g of ascorbic acid, 10.52 TSS, 109.7 mg/100g of phenolic content, and a pH of 3.2. Eight juice samples were prepared as per formulation with sodium benzoate and potassium metabisulfite (KMS) at concentrations of 150 ppm, 200 ppm, and 250 ppm, in addition to one refrigerated sample and one control. The stability of these guava juice samples was monitored every 15 days over a 90-day period. Results showed that acidity, TSS, pH, reducing sugars, and non-reducing sugars changed over time. Samples with preservatives exhibited slower changes compared to the control. Phenolic compounds diminished more quickly at ambient temperature than in refrigerated or preservative-treated samples. Initially, phenolic content and antioxidant capacity were 44 mg GAE/100g and 44 %, respectively, but declined to 10–15 mg and 15–17 % by the end of the storage period. Color changes were more noticeable in samples stored at room temperature, whereas preservatives effectively reduced color degradation caused by enzymatic browning. Moreover, ascorbic acid retention was better in samples with preservatives and those stored under refrigeration. The ascorbic acid degradation rate was highest at room temperature (0.023 day^-1) and lowest with 250 ppm KMS (0.016 day^-1). Microbiological tests indicated that the juice remained safe for 40 days at room temperature, 90 days under refrigeration, and approximately 85 days with preservatives.

Enhancing Insight into Photochemical Weathering of Flax and Miscanthus: Exploring Diverse Chemical Compositions and Composite Materials.

The accelerated weathering of flax and miscanthus fibers possessing distinct chemical compositions was investigated. The chosen fibers included raw, extractive-free (EF) and delignified samples (x3), alone and used as fillers in a stabilized polypropylene blue matrix (PP). Modifications in both color and the chemical composition of the fibers throughout the weathering process under ultraviolet (UV) light were meticulously tracked and analyzed by spectrophotometry and attenuated total reflectance with Fourier-transform infrared spectroscopy (ATR-FTIR). The inherent nature and composition of the selected fibers led to varied color-change tendencies. Raw and EF flax fibers exhibited lightening effects, while raw and EF miscanthus fibers demonstrated darkening effects. Extractives exhibited negligible influence on the color alteration of both flax and miscanthus fibers. This disparity between the fibers correlates with their respective lignin content and type, and the significant formation of carbonyl (C=O) groups in miscanthus. Better stability was noted for delignified flax fibers. A comparative study was achieved by weathering the PP matrix containing these various fibers. Contrary to the weathering observations on individual fibers, it was noted that composites containing raw and EF flax fibers exhibited significant color degradation. The other fiber-containing formulations showed enhanced color stability when compared to the pure PP matrix. The study highlights that the UV stability of composites depends on their thermal history. As confirmed by thermogravimetric analysis (TGA), fiber degradation during extrusion may affect UV stability, a factor that is not apparent when fibers alone are subjected to UV aging.