Color Pigments Research Articles

Enhancing wood coatings with red beetroot-derived pigments: Investigating synergy with UV absorber and composite filler for improved durability and aesthetics

The objective of this study is to assess the synergy among a specific bio-based pigment derived from red beetroot, a composite filler, and a UV absorber as additives for wood paints. The composite filler aims to enhance the mechanical properties of the coating, while the UV absorber is selected to improve the pigment's color stability under solar radiation. The impact of these additives on sample aesthetics is evaluated through color, gloss, and roughness measurements. Mechanical properties are analyzed using Buchholz surface hardness and Taber abrasion resistance tests. The protective role of the UV absorber is further examined through accelerated degradation tests in a UV-B chamber. To ensure that the additives do not compromise the coating's barrier properties, water uptake tests, resistance to liquids, and contact angle measurements are conducted. Overall, the study demonstrates how each additive serves a distinct purpose and their combined application offers benefits such as enhanced color retention and improved mechanical durability of the coating. It highlights the potential of using bio-based pigments to enhance color durability without sacrificing the protective performance of wood coatings.

A smartphone image-based method for the colorimetric characterization of historical pigments in mural paintings

In this article, the detailed description of a smartphone-based analytical method to turn a smartphone into a colorimeter is described and applied to mural painting replicas. The method consists of a camera characterization process, to estimate CIELAB values from RGB camera responses, correcting for potential experimental interferences, like the effect of the lighting/capture geometry or software for color modification and enhancement. Next, the estimated CIELAB descriptors were used to build a chemometric Support Vector Classifier to objectively distinguish among the colors of the different pigments. The method was validated in terms of color reproduction and classification performance.•A smartphone-based method is described to capture mural painting color.•A color gamut-specific camera characterization procedure is developed and the performance of the smartphone-based colorimeter is compared with a spectrophotometer.•A classification method based on the estimated CIELAB descriptors is validated in terms of classification performance.

PIGMENTS AS A MASS MATERIAL: DISCUSSION OF THE METHODOLOGICAL APPROACH IN RESEARCH

Archaeological and natural science studies of Paleolithic paint pigments (ocher) date back more than 100 years. However, until recently, the vast majority of studies were focused on the study of individual samples, not the whole corpus of this category of materials - mineral paint raw materials (in the broad sense of the term). The description of the theoretical approach and the available results obtained in the course of testing the method of the fixation of field data and laboratory processing of ocher samples, which come in different shapes, sizes and differ in consistency, clearly demonstrate that it is fundamentally important to conduct an archaeological study of colorful pigments as a mass material prior to the natural science stage of the study. In the opposite case even goal-setting for subsequent interdisciplinary research will be virtually impossible, and its results will be extremely limited. A multifactorial study of paint materials can demonstrate a great variety of sample characteristics, both among different layers of archaeological material and artifacts from the same site, and among different sites. When approaching pigments as a mass material, statistical processing of the findings is necessary to form meaningful conclusions about the use of pigments on sites. The afore-said methodological approach reveals systemic differences, which opens up opportunities for comparison based on the methods of mathematical statistics. To obtain relevant data, such an approach requires the accumulation of a statistically significant number of pigment samples, suitable from the point of view of field algorithms. Consequently, it is only the study of a maximum available array of specimens (including a maximum of small grains) of ocher from different artifacts of the cultural layer, individual layers and different sites that makes it possible to obtain information about the cultural similarities and differences in this part of the life strategies of Upper Paleolithic groups, including the identification of the main stages of production chain. The proposed approach to the study of ocher as a mass material, if complying with the methodology of field work, is relevant for all types of archaeological sites of the Stone Age.

Genome-wide association study reveals candidate genes critical for skin pigmentation in common carp (Cyprinus carpio) strains including koi

The differentiation and variation of body color in fish is an important component of biological evolution and phylogenetic research, and is influenced by several factors such as heredity, nutrition, physiological hormones and rearing conditions, with heredity being the most critical factor. An improved comprehension of the genetic regulation in different carp populations will facilitate future applications of precision breeding and pigment cell development-related genes editing. In this study, we used restriction site-associated DNA sequencing (2d-RAD) to determine the distribution characteristics of single nucleotide polymorphisms (SNPs) in eight common carp strains including six koi strains, i.e., Kohaku (Hb), Taisho (Dz), Showa (Zh), Golden (Hj), Matsukawabake (Sch) and Five-color (Ws), and two genetically improved breeding strains, i.e., FFRC No. 2 strain (Fr) and red FFRC strain (Hfr), and then SNP markers to resolve genetic information on the population structure and skin color formation of these strains. We found that most individuals of eight strains were clearly divided into eight clades. Genetic diversity within Fr, Sch and Ws is relatively high, while it is low within Dz, Hb and Hfr. A comparison between the populations revealed that Hfr and Ws have the highest degree of genetic differences, while Hb and Dz have the lowest. The GWAS analysis for two strategies identified several SNPs that are significantly related to skin color variation and affect melanin synthesis (ephrinb2, slc22a23, herc2, ephb2), carotenoid metabolism (oca2, bcmo1, bco2) and circadian rhythm(cipc). To summarize, our study provides some information on the genetic structure and diversity of Japanese koi and Chinese FFRC carp. Furthermore, based on the data obtained on relevant genes related to skin color differentiation and pigmentation, it can provide a theoretical basis for the subsequent integration of dominant traits and precision breeding in carps.

Phase evolution of nanocrystalline Mn-based oxides screened under different calcination temperatures using different precursors for proficient application in near infrared pigmentation

We examined how different calcination temperatures and precursors affect the formation of Mn-based oxides. The formation of these oxides was influenced by both the temperature (400–––1000 °C) and the type of precursors used (MnCl2·4H2O, MnCO3, MnO2, and KMnO4). When MnCl2·4H2O was calcined at 800 and 1000 °C/3h, we obtained pure tetragonal Mn3O4 phase materials. Calcining MnCO3 at 600 and 1000 °C resulted in cubic Mn2O3 and tetragonal Mn3O4 phase materials, respectively. Heating commercial MnO2 powder at 600 and 800 °C transformed it into cubic Mn2O3 phase materials. At 400 °C, the tetragonal MnO2 phase remained, but at 1000 °C, mixed Mn3O4 and Mn2O3 phases formed. Calcining KMnO4 at 1000 °C/3h led to the formation of δ-MnO2 materials. The morphological features of Mn2O3 and Mn3O4 materials exhibited different sizes and shapes, including nanostone-like, nanorod-like, and nanoflakes morphologies. The thermal analysis revealed significant differences in weight loss and thermal events, including exo and endothermic peaks. The Raman spectra and UV–Vis DRS measurements data support the formation of Mn-based oxides. The highest NIR reflectance for the various synthesized materials of Mn3O4 phase indicates a reflectance of 68 % in the solar region and 91 % in the color pigment region.

Highly Stable Hybrid Pigments Prepared from Organic Chromophores and Fluorinated Hydrotalcites

Structural hydroxide groups in layered magnesium–aluminum double hydroxides were partially replaced by fluoride ions. Fluorinated and fluorine-free materials were used as hosts for two dyes, carminic acid and hydroxyl naphthol blue, resulting in a hybrid pigment color palette. The pigments were produced by two ways, either incorporating chromophore during the synthesis of the layered double hydroxide or in a post-synthesis step through the memory effect of the LDHs. Additionally, the pigments were protected with a magnesium hydroxide phase to prevent the color from fading over time. The pigments were stable for periods as long as 10 years. The color properties of the pigments were significantly influenced by the host of dye since the presence of fluorine directly influences the acid–base properties of the layered double hydroxides. The pigments conferred their color to white cream in the preparation of colored creams. The colored creams acquired the color of the layered pigment.

Mesoporous silica aerogels for sunflower oil refining and investigation of their adsorption performance

AbstractInvolving a succession of oil refining stages for edible oil production, a notable constraint lies in the necessity to employ diverse adsorbents at various steps within these processes. This study investigates the synthesis of mesoporous silica aerogels from rice husk ash, comparing their efficacy in physical sunflower oil refining with earth clay (Bentonite) and commercial silica (Trisyl). Tetraethyl orthosilicate (TEOS) impact during aging was analyzed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and N2 adsorption-desorption analyzer to examine alterations in the structure of silica aerogels. The surface areas of TEOS-doped silica aerogel (TSA) and non-TEOS-doped silica aerogel (NTSA) were 296.18 and 267.06 m²/g. Mesoporous silica aerogels were evaluated for their ability to reduce free fatty acids (FFA), peroxide value (PV), phosphorus, and color pigments in sunflower oil. TSA and NTSA demonstrated significant FFA removal, with TSA at 3 wt.% achieving the highest performance of 32.2%. TSA also effectively reduced PV and phosphorus compared to NTSA, Bentonite and Trisyl, exhibiting performance similar to Bentonite in the bleaching process. TEOS-doped silica aerogels have shown promise as adsorbents for impurity removal in sunflower oil and has emerged as the potential adsorbent that can comprehensively and effectively meet the requirements of many edible oil physical refining applications in a singular step. Graphical Abstract

The pattern of genetic variability in a core collection of 2,021 cowpea accessions.

Cowpea is a highly drought-adapted leguminous crop with great promise for improving agricultural sustainability and food security. Here, we report analyses derived from array-based genotyping of 2,021 accessions constituting a core subset of the world's largest cowpea collection, held at the International Institute of Tropical Agriculture (IITA) in Ibadan, Nigeria. We used this dataset to examine genetic variation and population structure in worldwide cowpea. We confirm that the primary pattern of population structure is two geographically defined subpopulations originating in West and East Africa, respectively, and that population structure is associated with shifts in phenotypic distribution. Furthermore, we establish the cowpea core collection as a resource for genome-wide association studies by mapping the genetic basis of several phenotypes, with a focus on seed coat pigmentation patterning and color. We anticipate that the genotyped IITA Cowpea Core Collection will serve as a powerful tool for mapping complex traits, facilitating the acceleration of breeding programs to enhance the resilience of this crop in the face of rapid global climate change.

Hair Evaluation in Orthodontic Patients with Oligodontia.

Oligodontia can be isolated or syndromic, associated with other ectodermal abnormalities. The aim of the study was to perform hair examination in orthodontic patients diagnosed with oligodontia with a low clinical expression of symptoms of ectodermal origin. All available orthodontic patients diagnosed with oligodontia in the permanent dentition were enrolled. Hair examination included clinical evaluation of the patients' hair, trichoscopy, trichogram and evaluation of the hair shafts under a polarized light microscope. In total, 25 patients, 18 males and 7 females, aged 6 to 24 years were evaluated for the presence of dental and hair abnormalities. The number of congenitally absent teeth ranged from 6 to 24 teeth and diastemas, microdontia, taurodontism and altered tooth shape were found in 23 patients. Hair disorders were found in 68% of the subjects. Hypotrichosis, the heterogeneity of shaft color and loss of pigment, androgenetic alopecia, telogen effluvium, trichoschisis, pili canaliculi, trichorrhexis nodosa and pseudomoniletrix were observed. Trichoscopy and trichogram are valid non-invasive diagnostic tests which could be used to differentiate between isolated and syndromic oligodontia in patients with a low clinical expression of ectodermal symptoms.

The Effect of Home Bleaching on Color Match with Anterior Single Shade Composite Restoration

Background: Aim of this study is to assess the color matching in class III restorations made with single-shade resin composite after bleaching with different carbamide peroxide concentrations. Methods: In this study, 20 human incisors that were free of caries or enamel abnormalities and freshly extracted for periodontal or orthodontic reasons were cleaned of blood, debris, and calculus. Mesial and distal surfaces were restored with single-shade composite (Omnichroma, Tokuyama, Japan). All samples were randomly divided into two groups, all of the mesial surfaces were isolated, and distal surfaces were coated with %10 and %15 carbamide peroxide (Opalescence PF; Ultradent Products, Inc, USA). Polishing discs (Zenit Flex, President Dental, Germany) were used the composite restoration. Color matching was evaluated on photographs with a digital colorimeter. SPSS software program was used to perform statistical analysis (IBM Corp., Armonk, NY, USA). Results: Statistically significant difference was found between the color matching of the restorations after the 5th treatment with 15% carbamide peroxide (p = 0.004), and at the end of 10th treatment with 10% carbamide peroxide (p = 0.028). Depending on the carbamide peroxide concentration, after the 5th treatment a statistically significant difference was found between 15% and 10% carbamide peroxide (p = 0.000), but no statistically significant difference after the 10th treatment (p > 0.05). Conclusions: After carbamide peroxide bleaching, hard tissue color became lighter. Since there is no color pigment in single-shade composites, color might be lighter after bleaching. Therefore, these composites may be considered safer in bleaching. Keywords: Bleaching, Color Match, Composite

Identifying a novel Listeria innocua subgroup and enhancing Listeria detection in grain: A duplex real-time PCR approach informed by comparative genomic analysis

This study focuses on enhancing the detection accuracy of Listeria species in the food industry, particularly addressing the challenges posed by closely related strains that complicate pathogen identification. Detecting Listeria monocytogenes, a key psychrotolerant foodborne pathogen, is crucial in the food industry. Although real-time PCR-based methods targeting the iap gene are commonly employed for identification, our investigation of L. innocua strains isolated from wheat in South Korea revealed false positives, indicating an imperative for more accurate detection approaches. We used comparative genomic analysis to identify a novel subgroup of L. innocua with closer genomic affiliations to L. monocytogenes. Consequently, we developed new primer and probe sets for more accurate detection of both L. monocytogenes and L. innocua, demonstrating high specificity and selectivity. Additionally, we revealed the importance of food matrix effects, particularly color pigments, in the design of diagnostic assays. These advances provide insight into genomic differences between L. monocytogenes and L. innocua, and pioneer new detection techniques for Listeria species.

Empirical BRDF model for goniochromatic materials and soft proofing with reflective inks.

The commonly used analytic bidirectional reflectance distribution functions (BRDFs) do not model goniochromatism, that is, angle-dependent material color. The material color is usually defined by a diffuse reflectance spectrum or RGB vector and a specular part based on a spectral complex index of refraction. Extension of the commonly used BRDFs based on wave theory can help model goniochromatism, but this comes at the cost of significant added model complexity. We measured the goniochromatism of structual color pigments used for additive color printing and found that we can fit the observed spectral angular dependence of the bidirectional reflectance using a simple modification of the standard microfacet BRDF model. All we need to describe the goniochromatism is an empirically-based spectral parameter, which we use in our model together with a specular reflectance spectrum instead of the spectral complex index of refraction. We demonstrate the ability of our model to fit the measured reflectance of red, green, and blue commercial structural color pigments. Our BRDF model enables straightforward implementation of a shader for interactive preview of 3D objects with printed spatially and angularly varying texture.

Insights into the mechanism of color formation of the freshwater prawn (Macrobrachium rosenbergii) revealed by de novo assembly transcriptome analysis

Body color is an important visual indicator of crustacean quality and plays a major role in consumer acceptability, perceived quality, and the market price of crustaceans. The freshwater prawn (Macrobrachium rosenbergii) has two distinct phenotypic variations, characterized by dark blue and light yellow body colors. However, the underlying mechanisms regulating the body color of M. rosenbergii remain unclear. In this study, the composition of shell color parameters and pigment cells of raw and cooked dark blue and light yellow M. rosenbergii was investigated and the mechanisms associated with body color were elucidated by transcriptome analysis. The results showed significant differences in the raw shells of the dark blue and light yellow M. rosenbergii (L: 26.20 ± 0.53 vs. 29.25 ± 0.45; a: −0.88 ± 0.19 vs. 0.35 ± 0.18; b: 1.73 ± 0.20 vs. 3.46 ± 0.37; dE: 70.33 ± 0.53 vs. 67.34 ± 0.45, respectively, p = 0.000) as well as the cooked shells (L: 58.14 ± 0.81 vs. 55.78 ± 0.55; a: 19.30 ± 0.56 vs. 16.42 ± 0.40; b: 23.60 ± 0.66 vs. 20.30 ± 0.40, respectively, p < 0.05). Transcriptome differential gene analysis obtained 39.02 Gb of raw data and 158,026 unigenes. Comprehensive searches of the SwissProt, Nr, KEGG, Pfam, and KOG databases resulted in successful annotations of 23,902 (33 %), 40,436 (25.59 %), 32,015 (20.26 %), 26,139 (16.54 %), and 22,155 (14.02 %) proteins, respectively. By KEGG pathway analysis, numerous differentially expressed genes were related to pigmentation-related pathways (MAPK signaling pathway, Wnt signaling pathway, melanin production, tyrosine metabolism, and cell-cell communication process). Candidate DEGs that may be involved in body color included apolipoprotein D, crustacyanin, cytochrome P450, and tyrosinase, as verified by quantitative real-time PCR. The results of this study provide useful references to further elucidate the molecular mechanisms of color formation of M. rosenbergii and other crustaceans.

Relationship of skin complexion with gingival tissue color and hyperpigmentation. A multi-ethnic comparative study

Background and ObjectiveThe most frequently seen intra-oral soft tissue is the gingiva. Most often, it is seen as coral-pink tissue that surrounds the neck of the teeth. Gingiva that encircles the tooth necks and covers the alveolar processes of the jaws is an intra-oral tissue that exhibits biomimetic features. The wide range of colors of the gingiva depends on the configuration of gingival vascularity, the degree of epithelial cornification, level of melanogenesis, and the depth of epithelialization. However, the color of the gingiva varies depending on the degree of melanin pigmentation. The current study aimed to identify the different distribution patterns of gingival color and determine the correlation between skin color, gender, and geographical area of origin.Materials and methodsA total of 839 subjects were involved in the study where the gingival color and skin tone were measured using the Dummett-Gupta Oral pigmentation Index (DOPI) combined with VITA VMK MASTER and skin shade method developed by Revlon (USA) and L’Oreal (France) for makeup foundation shades. One investigator was calibrated for the examination of the colors after being tested for normal color vision and color aptitude using the line test.ResultsA significant association was found between skin color and gingival pigmentation (χ2 value (6) = 114.48; P = 0.001). It was also found that females (67.1%) significantly had darker gingiva than males (58.3%). The study statistics display that location of the individual was also statistically associated with melanin pigmentation of the gingiva (χ2 value (57) = 559.33; P = 0.001).ConclusionThe study concluded that gender, skin color, and individual location are significantly associated with gingival melanin pigmentation.

An Insight into the Hormonal Interplay Regulating Pigment Changes and Colour Development in the Peel of ‘Granny Smith’, ‘OPAL®’ and ‘Royal Gala’ Apples

AbstractThree apple cultivars with different peel colour and known ripening dynamics were examined throughout development and on-tree ripening to unravel how the hormonal crosstalk may influence colour changes. Our results indicate that the colour of ripe apples in ‘Granny Smith’ and ‘Opal®’ cultivars was primarily influenced by chlorophyll levels masking the contribution of other pigments, whilst the development of red colour in the ‘Royal Gala’ was not only due to an important loss of chlorophyll during ripening but also to anthocyanins accumulation. The interplay amongst indole-3-acetic acid (IAA), ethylene and abscisic acid (ABA) seemed to control pigment content during the later stages of development, indicating that variations in the hormonal profile contribute to colour differences in ripe apples. In ‘Granny Smith’ apples, basal levels of IAA, ethylene and ABA were associated with the inhibition of chlorophyll loss, which was responsible for its green colour, despite the presence of high carotenoid levels. In contrast, the peel of ‘Opal®’ and ‘Royal Gala’ apples underwent a degreening process facilitated by the IAA-mediated activation of ethylene metabolism, in a crosstalk facilitated by MdARF5. The accumulation of anthocyanins in the peel of ‘Royal Gala’ apples seemed to be regulated in an ethylene-dependent manner, with MdMYB1 acting as the mediator between ethylene signalling and the anthocyanins biosynthesis and vacuolar transport pathways. On the other hand, the decline in carotenoid content during fruit development in the three cultivars appeared to be regulated at the catabolic level through ABA and its derivatives and possibly also facilitated by ethylene-mediated mechanisms. Notably, chlorophyll levels, crucial for the observed colour changes, were likely controlled by MdGLK1, a transcription factor involved in chloroplast biogenesis, working in coordination with ethylene-dependent catabolic enzymes. Overall, understanding the cultivar-specific hormonal regulation of apple colour provides valuable insights for developing preharvest and postharvest strategies to ensure an optimal fruit colour aligned with consumer preferences.

Non-iridescent magnetite photonic crystal films and pigments with enhanced magnetic coupling effect

Non-iridescent structural color films and pigments with novel enhanced microwave absorption characteristics are successfully fabricated at room temperature for the first time. The quasi-uniform magnetite nanoparticles (CV = 0.10 ∼ 0.20) with high refractive index (n = 2.42) and broad light absorption provide evident low-angle-independent property for the structural color pigments. More importantly, a universal technical protocol is developed for preparation of photonic crystals with inorganic nanoparticles, i.e., through designing of the binding strength between nanoparticles and mediated molecules, the slurry modulus is increased to 105 Pa, which effectively drives the nanoparticles to rapidly assemble into closely packed ordered arrays by our-designed powerful assembly technique. Additionally, the structural color materials are subjected as photonic crystal pigments (∼20 wt%) embedding in a transparent polymer matrix to form color coatings. Remarkably, the photonic crystal pigments exhibit strong magnetic coupling effect and enhanced microwave absorption performance due to the regular arrangement, with superior reflection loss (RLmin) values of −14.97 dB (increase by 65.8 % compared with randomized magnetic nanoparticles), and the effective absorption bandwidth (EAB) of 2.15 GHz. This new kind of photonic crystal pigment, combining visual color and radar wave absorption, provides a novel idea for developing of multi-wave-band high-performance stealth materials.

Valorization of waste seashells as bioadsorbent for sunflower oil bleaching

AbstractIn this study, the performance of waste seashells (SS) in adsorbing color and oxidation parameters during the bleaching process of sunflower oil was evaluated and compared with that of commercial clay. Seashell activation methods included microwave treatment (900 W for 30 min), acid treatment (7 N H2SO4), and a combination of both. Interestingly, the unactivated SS demonstrated superior adsorption performance compared with the activated SS. SS, which have the ability to eliminate color pigments like chlorophyll and carotenoid, were found to be effective in this regard. However, their effectiveness in reducing the peroxide and p‐anisidine value was not as successful as that of commercial clay. Free acidity content remained constant across all treatments. SS emerged as a cost‐effective alternative adsorbent, promising in preventing environmental pollution. Their use signifies a valuable contribution to sustainability. This study sheds light on SS potential as an eco‐friendly solution in industrial processes, warranting further exploration and application.Practical applicationsBiowaste valorization is a process that involves converting organic waste materials into valuable products, energy, or resources, instead of simply disposing of them in landfills or incinerating them. This approach has gained significance owing to its potential to address environmental, economic, and social challenges. In this respect, this study presents that bioadsorbent obtained from waste SS can be utilized for bleaching of sunflower oil.

Tyrosinase Inhibitory Activity of n-Hexane, Ethyl Acetate and Methanol Extracts of Padina sp

Melanin is a color pigment in the skin, if produced in excess will cause browning of the skin. The formation of melanin (melanogenesis) is assisted by tyrosinase through two reactions, namely monophenolase and diphenolase. Melanogenesis can be reduced through the tyrosinase enzyme inhibition mechanism. Seaweed can be used as a tyrosinase inhibitor (brightening agent), such as Padina sp containing secondary metabolites such as alkaloids, flavonoids, terpenoids, phenolics, and saponins. This study aimed to determine the tyrosinase inhibitory activity of Padina sp. The extraction method used was graded maceration with n-hexane (n-Hx), ethyl acetate (Et-OAc), and methanol (Me-OH) solvents, then carried out phytochemical screening, antioxidant test using the DPPH method, and tyrosinase inhibitory test by measuring the enzymatic reaction using L-tyrosine (monophenolase) and L-DOPA (diphenolase). Phytochemical analysis of extracts by GC-MS and in silico analysis by molecular docking were also carried out. The results showed that the total yield of the three extracts was 5.50%. The three extracts had moderate category of antioxidants. The IC50 values monophenolase of n-Hx, Et-OAc, Me-OH extracts, and Kojic acid were 937.68; 132, 92; 268.68; and 20.99μg/mL, respectively. The IC50 values diphenolase of n-Hx, Et-OAc, Me-OH extracts, and Kojic acid were 989.74; 178.33; 356, 87; and 31.76 μg/mL, respectively. The phytochemical of Et-OAc extract based on GC-MS data showed a variety of compounds that have been shown to have pharmacological effects. This data is supported by the results of molecular docking analysis, where compound Spiro(tetrahydrofuryl)2.1'(decalin), 5',5',8'a-trimethyl (1) is able to show a relatively low binding energy, namely -6.86 kcal/mol. The binding energy is even lower than the standard compound (Kojic acid) interaction which only has binding energy of -3.73 kcal/mol. Based on the study carried out, extract from Padina sp has the potential to be developed as a a skin brightening agent.

The effect of pH and extraction time on total phenolic content and antioxidant properties of coloured water extracts from Brassica Oleracea

Red cabbage (Brassica oleracea) is a rich source of phenolic content including colour pigments and have also high antioxidant capacities. The amounts of their phenolic substances and antioxidant activities change depending on the extraction conditions (pH, time, solvent, etc.). In this work, the coloured water extract was obtained from red cabbage at different pH values (pH 4-10) for both an hour and 24 hours. The extracts were evaluated regarding total phenolic contents and antioxidant activities. The results showed that the total phenolic content of red cabbage extracts in all extraction conditions ranged from 4.93±0.20 to 7.59±1.22 mg GAE/g fw. The highest total phenolic contents (7.59±1.22 mg GAE/g fw) were obtained from red cabbage at 24 h and pH=6. On the other hand, the red cabbage extracts have high DPPH (IC50 values ranged from 0.21±0.06 to 0.94±0.03 mg/mL) and ABTS (IC50 values ranged from 0.29±0.01 to 0.46±0.05 mg/mL) activities at all pH values and times. The extract obtained from red cabbage at 1 h and pH=7 exhibited the strongest DPPH activity with the IC50 values of 0.21±0.06 mg/mL, it showed the best ABTS activity with the IC50 values of 0.29±0.01 mg/mL at 1 h and pH=5 and 8.

Ensemble machine learning as a mathematical approach to predict high-voltage electric field-assisted removal of color and oxidative indices from soybean oil using the activated porous electrodes

Porous electrode materials provide a large surface area for electrochemical reactions and facilitate ion transport efficiently. By optimizing the design and properties of porous electrodes, it is possible to enhance the bleaching performance. In this research, three machine learning (ML) algorithms, namely Support Vector Regression, Ridge Regression, and Decision Tree Regression were utilized for predicting the bleaching efficiency under different conditions of HVEF-assisted bleaching (HVEFAB). Subsequently, the outcomes of these models were compared to ensemble models created by combining the algorithms as mentioned earlier using three techniques including bagging, boosting, and stacking. The levels of chlorophyll and carotenoids were reduced as a result of increased voltage, modification in the electrode surface, number of cathode-anode, and the presence of an inert electrolyte. Meanwhile, the reduction of red color and chlorophyll pigments was more significant than yellow color and carotenoid pigments. Moreover, the application of HVEFAB can potentially decrease the levels of polar compounds, such as oxidative compounds on the electrode surface. Based on the MSE, MAE, and R2 metrics, the algorithms' efficacy in forecasting outputs 1 (color index) and 2 (oxidative index) can be ordered as follows: Stacking > Boosting > Bagging > Decision Tree (DT) > Ridge > Support Vector Regression (SVR). The findings demonstrate that integrating these three models, mainly through the stacking technique, substantially improves the accuracy of the predicting model. Particle swarm optimization (PSO) and polynomial regression rather than RSM represented a superior model to predict red color removal.