Search Results (76)

This study evaluated the effects of different storage conditions, varying in light exposure, relative humidity (RH), and packaging materials, on the physicochemical stability of Lobosphaera sp. biomass, the retention of bioactive compounds, and the bioactivity of its extracts. Under light and 75% RH, the biomass absorbed moisture over time, reaching 0.779 ± 0.003 g/g dry weight (DW) after three months. This was accompanied by a decline in luminosity, chroma, and hue values. In contrast, samples stored under other conditions showed minimal changes, indicating that high humidity, combined with light exposure, compromises biomass stability. Packaging in metalized polyethylene terephthalate (PETmet/PE) effectively preserved the water content, color, and carotenoid levels during a two-month storage period. Bioactive compounds extracted via hydroethanolic ultrasound-assisted extraction yielded 15.48 ± 1.35% DW. Total phenolic content (TPC) of the extracts declined over time in both PETmet/PE and low-density polyethylene (LDPE) packaging, though the decrease was less pronounced in PETmet/PE. Antioxidant activity, assessed via the ABTS assay, remained stable, regardless of storage duration or packaging. Antimicrobial activity of the extract decreased over time but remained more effective against Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes), with PETmet/PE packaging better preserving antimicrobial efficacy than LDPE. These findings underscore the importance of optimized storage conditions and packaging for maintaining the quality and bioactivity of Lobosphaera sp. biomass and its extracts. Full article

Single-image super-resolution refers to the reconstruction of a high-resolution image from a single low-resolution observation. Although recent deep learning-based methods have demonstrated notable success on simulated datasets—with low-resolution images obtained by degrading and downsampling high-resolution ones—they frequently fail to generalize to real-world settings, such as document scans, which are affected by complex degradations and semantic variability. In this study, we introduce a task-driven, multi-task learning framework for training a super-resolution network specifically optimized for optical character recognition tasks. We propose to incorporate auxiliary loss functions derived from high-level vision tasks, including text detection using the connectionist text proposal network (CTPN), text recognition via a convolutional recurrent neural network (CRNN), keypoints localization using Key.Net, and hue consistency. To balance these diverse objectives, we employ a dynamic weight averaging (DWA) mechanism, which adaptively adjusts the relative importance of each loss term based on its convergence behavior. Experimental evaluation demonstrates that the proposed approach improves text detection, measured with intersection over union, by 1.09% for simulated and 1.94% for real-world datasets containing scanned documents, while preserving overall image fidelity. These improvements are statistically significant as confirmed by the Kruskal–Wallis H test and the post hoc Dunn test with Benjamini–Hochberg p-value correction. Our findings highlight the value of multi-objective optimization in super-resolution models for bridging the gap between simulated training regimes and practical deployment in real-world scenarios. Full article

The growing concern over the presence of polycyclic aromatic hydrocarbons (PAHs) in grilled meats has intensified the search for natural mitigation strategies. This study evaluates the effect of red grape pomace (RGP), a natural by-product with antioxidant properties, on the lipid stability, color, fatty acid profile, volatile compounds, and PAHs formation in barbecued pork burgers. Unlike previous studies focusing on polyphenol extracts, this work investigates, for the first time, the direct incorporation of whole RGP stabilized by high hydrostatic pressure (HHP), a method that preserves its bioactive profile and ensures food safety. Incorporation of RGP at different levels (0.5%, 1%, and 3%) demonstrates its potential as a functional ingredient in meat products. Our results show that RGP effectively inhibits lipid oxidation, as indicated by significantly lower malondialdehyde (MDA) levels (p < 0.001) compared to control batches. It also modified the fatty acid profile by reducing saturated fatty acids and increasing the linoleic acid content (up to 15.56% at the 3% level). As the RPG concentration increased, color parameters (lightness, redness, yellowness, chroma, and hue) decreased significantly (p < 0.001), particularly at higher pomace levels (1% and 3%). The RGP did not significantly affect the PAH concentration, indicating its safe use in barbecued products. However, it selectively influenced volatile compounds, decreasing the hydrocarbon levels at higher concentrations, likely due to its antioxidant properties. These findings suggest that stabilized RGP may serve as a natural additive that enhances the nutritional quality and reduces lipid oxidation, without promoting PAH formation in thermally processed meats. Full article

Dominant colors significantly influence visual image perception and are widely used in computer vision and design. Traditional extraction methods often neglect visually salient colors that occupy small areas yet possess high aesthetic relevance. This study introduces a method for detecting both dominant and visually prominent colors in a wide range of hues and images. We analyzed the color gamut of images in the CIE L^*a^*b^* color space and concluded that it is difficult to identify the dominant and prominent colors due to high color variability. To address these challenges, the proposed approach transforms images into the orthogonal ICaS color space, integrating the properties of RGB and CMYK models, followed by K-means clustering. A spectral residual saliency map is applied to exclude background regions and emphasize perceptually significant objects. Experimental evaluation on an image database shows that the proposed method yields color palettes with broader gamut coverage, preserved luminance, and visually balanced combinations. A comparative analysis was conducted using the ΔE₀₀ metric, which accounts not only for differences in lightness, chroma, and hue but also for the perceptual interactions between colors, based on their proximity in the color space. The results confirm that the proposed method exhibits greater color stability and aesthetic coherence than existing approaches. These findings highlight the effectiveness of the orthogonal saliency mean method for delivering a more perceptually accurate and visually consistent representation of the dominant colors in an image. This outcome validates the method’s applicability for image analysis and design. Full article

The increasing prevalence of microplastic (MP) pollution and the labor-intensive nature of existing identification methods necessitate improved large-scale detection approaches. Nile Red (NR) fluorescence, which varies with polarity, offers a potential classification method, but standardization of carrier solvents and fluorescence differentiation techniques remains lacking. This study evaluated eight NR-carrier solvents (n-hexane, chloroform, acetone, methanol, ethanol, acetone/hexane, acetone/ethanol, and acetone/water) across ten common MP polymers (HDPE, LDPE, PP, EPS, PS, PC, ABS, PVC, PET, and PA). Fluorescence intensity, Stokes shift, and solvent-induced polymer degradation were analyzed. The study also assessed HSV (Hue/Saturation/Value) color spaces for Stokes shift representation and MP differentiation. Fenton oxidation effectively quenched fluorescence in natural organic matter (e.g., eggshells, fingernails, wood, cotton) while preserving NR-stained MPs. Acetone/water [25% (v/v)] emerged as the optimal solvent, balancing fluorescence performance and minimal degradation. Full article

This study systematically investigates the effects of repeated Kurome treatment—a physical modification method combining mechanical stirring and oxidative regulation—on the processing characteristics and film properties of Chinese lacquer (urushi). By subjecting raw lacquer to 1–4 cycles of hydration–dehydration (KL1–KL4), the researchers observed a significant increase in viscosity (from 12,688 to 16,468 mPa·s) and a dramatic reduction in curing time (from 74 h to just 3.6 h), driven by deep oxidation of urushiol and quinone-mediated crosslinking, as confirmed by FTIR spectroscopy. The Kurome treatment enabled controlled darkening (L* value decreased from 29.31 to 26.89) while maintaining stable hue and gloss (88.96–90.96 GU), with no adverse effects on abrasion resistance (mass loss of 0.126–0.150 g/100 r) or adhesion (9.58–9.75 MPa). The reduced transparency of the KL3/KL4 films is associated with a densified polymer network, a feature that may benefit protective coatings. Scanning electron microscopy (SEM) analysis confirmed the formation of uniform, defect-free surfaces across all treatment groups. Among them, the KL2 group (viscosity of 14,630 mPa·s, curing time of 9.2 h) exhibited the most favorable balance for industrial applications. This study establishes Kurome technology as a low-carbon, additive-free strategy that enhances the processability of Chinese lacquer while preserving its traditional craftsmanship standards, offering scientific support for its sustainable use in modern coatings and cultural heritage conservation. Full article

The architectural legacy of the French colonial period forms a key part of Vietnam’s urban identity, especially in Hue. Yet, this heritage is rapidly declining: from over 240 structures in 2000, fewer than 100 remain today. This study introduces a heritage-based evaluation framework to assess and preserve French colonial buildings using Le Loi Street, Hue’s historic “Western quarter” as a pilot site. Fourteen colonial-era buildings were systematically assessed through field surveys and expert consultation. A total of 40 specialists participated in the criteria development process, and eight selected experts conducted detailed building evaluations. The final framework includes three main categories and nine specific criteria, based on a 100-point scale, incorporating architectural integrity, historical and cultural significance, contextual fit, and adaptive reuse potential. The results show that all the surveyed buildings qualify as Group A or B, warranting strict conservation or minimal renovation. The study emphasizes the value of localized, expert-informed approaches to heritage planning. The research provides a practical foundation for integrating historic architecture into context-sensitive urban conservation strategies in Hue and comparable Southeast Asian contexts. Full article

Table grapes are widely cultivated worldwide and are highly appreciated by consumers for their sensory characteristics and high nutritional value. Recently, many researchers have focused on applying specific post-harvest preservation strategies, such as the use of ozone, which represents an environmentally and health-friendly approach to sanitizing and preserving fresh fruits. In addition, ozone acts as a stressor, stimulating the defense mechanism of fruits and the synthesis of polyphenols, important antioxidant compounds. This study aimed to investigate the effect of different concentrations of ozonated water (8 ppm and 12 ppm), cold stored for 12 (T1) and 24 (T2) days, on the weight loss, texture and color parameters, phenolic content, and antioxidant activity of ready-to-eat Italian ‘Regal seedless’ grapes. Weight loss increased during cold storage for all treatments; however, the control exhibited higher values at 12 and 24 days (0.30% and 1.06%, respectively). Cold storage clearly affects the color of grapes, resulting in a loss of brightness and saturation, an increase in the yellow component, and a reduction in hue. At T2, ozonated water showed a significant increase in total phenolic content (TPC), antioxidant activity (DPPH, ORAC), and some phenolic compounds, including gallic acid, kaempferol, and resveratrol, compared to the control. The results indicated that using ozonated water on grape berries could be an effective strategy for enhancing their shelf life and nutraceutical value in post-harvest treatment. Full article

This study evaluated the effects of selected polysaccharide edible coatings (apple pectin and sodium alginate) on the quality characteristics of fresh-cut beetroot. The changes in texture (hardness), optical parameters such as colour and Hue angle, polyphenols, flavonoids, and red and yellow colourants during 4 weeks of refrigerated storage, as well as changes in microstructure, were examined. Self-standing coatings have also been prepared and characterised by continuous structure without pores, cracks, and high lightness. The obtained results for hardness showed reduced values during storage. Colour parameters (L*, a*, and b*) and Hue angle remained mostly consistent, indicating the preservation of the desired colour, though slight changes were noted during storage. Lightness (parameter L*) increased over time, suggesting changes in the beetroot surface. However, these changes were less pronounced in samples covered with coatings. The use of polysaccharide coatings and storage time positively impacted flavonoids in fresh-cut beetroots, except after 28 days when the lowest values for both parameters were observed. It can also be noted that the polyphenol content in coated samples decreased at a slower rate. Moreover, there was a significant decrease in the content of red and yellow colourants for both control and coated samples. However, greater changes were noted for samples treated with coatings. Scanning electron microscopy used at 0 and 28 days showed lower pores in beetroot tissue as a result of applied polysaccharide coatings, and refrigerated storage negatively affected the minimally processed beetroot surface. Nevertheless, minimally processed beetroots obtained with the treatment of polysaccharide coatings as mild technology showed modifications to the quality characteristics, which can find practical use in reducing the waste of fresh-cut vegetables during storage. Full article

Chuño is a traditional Andean product obtained by freezing, thawing, and drying potatoes. This study aimed to assess how different Andean potato varieties (Chihuanki Negro [C], Puka Huayro Machu [P], and Yana Huayro Machu [Y]) and freezing temperatures (−10 °C, −20 °C, and −30 °C) modulate the physicochemical (pH, acidity, and moisture), bioactive (phenolics and antioxidant activity), nutritional (proximate composition and minerals), and techno-functional (water absorption and swelling power) attributes of chuño. The results revealed that variety C retained higher macronutrient levels at 10 °C, featuring higher carbohydrates, proteins, and minerals (e.g., magnesium and zinc), while P showed enhanced fiber and mineral retention, alongside a faster rehydration and antioxidant capacity, particularly at −20 °C and −30 °C. Color differences were also noted, with P presenting reddish tones and a higher luminosity, whereas C had a more intense yellow hue linked to carotenoids. In general, −10 °C and −20 °C better preserved antioxidant compounds than −30 °C. These findings underscore how the proper selection of potato variety and freezing temperature can optimize the nutritional, functional, and sensory characteristics of chuño. However, these outcomes stem from selected samples, suggesting that further research is needed to confirm the broader applicability of the proposed method across additional varieties and process conditions. Full article

To rectify significant heading calculation errors in polarized light navigation for unmanned aerial vehicles (UAVs) under tilted states, this paper proposes a method for compensating horizontal attitude angles based on horizon detection. First, a defogging enhancement algorithm that integrates Retinex theory with dark channel prior is adopted to improve image quality in low-illumination and hazy environments. Second, a dynamic threshold segmentation method in the HSV color space (Hue, Saturation, and Value) is proposed for robust horizon region extraction, combined with an improved adaptive bilateral filtering Canny operator for edge detection, aimed at balancing detail preservation and noise suppression. Then, the progressive probabilistic Hough transform is used to efficiently extract parameters of the horizon line. The calculated horizontal attitude angles are utilized to convert the body frame to the navigation frame, achieving compensation for polarization orientation errors. Onboard experiments demonstrate that the horizontal attitude angle estimation error remains within 0.3°, and the heading accuracy after compensation is improved by approximately 77.4% relative to uncompensated heading accuracy, thereby validating the effectiveness of the proposed algorithm. Full article

Almond peel extracts, containing 0.2–0.8% (w/w) phenolic compounds with notable antioxidant and antimicrobial activities, could be used as a natural source of active compounds for the development of active films for food preservation. In this study, almond peel extracts obtained by subcritical water extraction at 160 and 180 °C were incorporated into PLA films (PLA-E160 and PLA-E180). The films were characterized in terms of their microstructure, mechanical, barrier, optical and thermal properties. Furthermore, the release of phenolic compounds and hydroximethylfurfural (HFM) into food simulants with different polarity was evaluated, as well as the film’s potential antioxidant and antimicrobial activities. To validate their effectiveness as active packaging materials, shelf-life studies were conducted on fresh orange juice and sunflower oil packaged using PLA-160 films. The results show that the incorporation of the almond peel extracts led to significant changes in the films’ microstructure and mechanical properties, which became darker, mechanically less resistant, and stretchable (p < 0.05), with slightly lower thermal stability than neat PLA films. The release of phenolic compounds and HFM from extract-enriched films was promoted in the 95% ethanol simulant due to the matrix swelling and relaxation. Food products packaged with PLA-E160 exhibited slower oxidative degradation during storage, as indicated by the higher ascorbic acid content and hue color in orange juice and lower peroxide content in sunflower oil. Nevertheless, both in vivo and in vitro studies showed no antimicrobial effectiveness from the films, likely due to the limited release of active compounds to the surrounding medium. Thus, almond peel extract conferred valuable properties to PLA films, effectively reducing oxidative reactions in food products sensitive to these deterioration processes. Full article

The aim of this study was to compare selected physicochemical properties and sensory attributes of ricotta cheeses supplied by different producers and purchased from retail outlets in Poland. The experiment was performed on 40 fresh, unripened ricotta cheeses purchased from hypermarkets in the city of Olsztyn, Poland. The cheeses were supplied by four producers. To preserve the producers’ anonymity, the cheeses were divided into four experimental groups marked with the letters A, B, C, and D. Each group consisted of 10 cheeses supplied by the same producer. Immediately after purchase, the cheeses were transported to a laboratory for quantitative and qualitative analyses to determine their moisture contents, active and titratable acidity, shear force, color parameters (L*, a*, b*), chroma (C*), hue angles (h°), whiteness indexes (WIs), yellowness indexes (YIs), and sensory quality. The analyses revealed that the cheeses supplied by producers C and D were characterized by the highest moisture contents and the lowest titratable acidity and shear force values. The ricottas supplied by producer A were characterized by the highest values for lightness on the surface, whereas the group B cheeses were characterized by the highest contribution of redness and yellowness, as well as the highest color saturation (chroma). The contributions of redness and yellowness, chroma, and YI values were highest at the cross-sections of the group B cheeses. The cheeses supplied by producer D were characterized by visible spaces between grains, cracks, and a brittle, crumbly consistency, and they received the lowest scores for appearance at the cross-section for structure and consistency. Full article

Figs are highly perishable, with significant losses due to overripening or failure to meet market standards. Drying is essential to extending their shelf life and reducing food waste. This study evaluated the impact of traditional sun drying and hybrid solar drying on the quality of dried “Pingo de Mel” figs. Sun drying required 5–7 days, while the hybrid solar drying completed the process in 3 days. Both methods resulted in a similar final moisture content (29.43% and 28.14%, respectively), water activity (0.68 and 0.63, respectively), and hardness (2.36 and 2.61 N, respectively). Hybrid solar-dried figs exhibited slightly lower L* values and higher b* values, reflecting a darker appearance with a more pronounced yellow hue. Fresh and sun-dried figs developed fungal growth (Alternaria spp., Aspergillus niger, Cladosporium spp., and Fusarium spp.) within four weeks, while hybrid solar-dried figs remained contamination-free, improving microbial safety. Moreover, hybrid drying preserved higher levels of phenolic compounds, particularly rutin and 5-O-caffeoylquinic acid, along with greater antioxidant activity. Overall, hybrid solar drying offers significant advantages over traditional sun drying by reducing the drying time, enhancing microbial safety, and preserving bioactive compounds, making it a more effective method for fig preservation. Full article

Active packaging using an edible coating could be an essential and sustainable alternative solution to preserve the properties of fruits and to prevent food loss and food waste. Fruits generate significant food wastes and losses. Reducing food waste is a global priority. For this research, nature-based solutions (NBSs) were applied, using micro-sized chitosan (CsMPs) and selenium microparticles (SeMPs), which are green-synthesized from black tea leaf extracts, and thyme essential oil. In this study, the effects of the new generation active food preservative coating agents formed from combinations of micro-sized chitosan (CsMPs) and selenium (SeMPs), and thyme essential oil (Oil) on the quality of “0900 Ziraat” sweet cherry fruits after harvest were investigated. After the fruits were coated with edible colloid solution, they were stored at 4 °C and 21 °C for 20 days, and quality parameter analyses were performed on days 0, 5, 10, 15, and 20. As a result of this study, it was determined that the application of CsMPs + SeMPs and the subsequent application of CsMPs + SeMPs + Oil from colloid solution coatings reduced weight loss, respiration, and decay rates. Also, it was determined that these applications were the most effective in preserving color values (L*, chroma, and hue), fruit firmness, total soluble solid (TSS) amount, acidity content and total phenolics, anthocyanin, and antioxidant capacity. These results show that CsMPs + SeMPs and CsMPs + SeMPs + Oil applications can be used as edible coatings to preserve the quality of sweet cherry fruits and extend their shelf life after harvest. This study’s results will contribute to obtaining micro-sized composite coating agents/agents produced with new technology to extend the shelf life. Full article