Blue maize with pigmented germ: Phytochemical compounds and tortilla color.

Blue maize is used in the production of various traditional foods, and its phytochemical composition has been claimed to possess health benefits. In this study, two blue maize hybrids with pigmented germ grown in five environments were studied under the hypothesis that the germ could have a different anthocyanin profile from that of anthocyanins synthesized in the aleurone layer, and that those in the germ could increase the total anthocyanin content in the whole grain. The percentage of pigmented germ, total anthocyanin content (TA) and total soluble phenols in the germ, whole grain and tortilla were evaluated to determine how tortilla color is modified. For the first time, the anthocyanin and fatty acid profiles of pigmented germ were determined. In the anthocyanin profile, anthocyanins derived from peonidin stood out, making 50.7 %. The most abundant fatty acid was linoleic acid (40.6 %). Whole kernel TA content increased when the maize had a higher percentage of pigmented germ, with minimal changes when grain was transformed to tortilla, resulting in darker tortillas. The large variation in TA among environments highlights the importance of identifying the environments that most favor anthocyanin synthesis.

Transcriptome analysis reveals biosynthesis and regulation of flavonoid in common bean seeds during grain filling.

The Andean domesticated common beans (Phaseolus vulgaris) are significant sources of phenolic compounds associated with health benefits. However, the regulation of biosynthesis of these compounds during bean seed development remains unclear. To elucidate the gene expression patterns involved in the regulation of the flavonoid pathway, we conducted a transcriptome analysis of two contrasting Chilean varieties, Negro Argel (black bean) and Coscorron (white bean), at three developmental stages associated with seed color change, as well as different flavonoid compound accumulations. Our study reveals that phenolic compound synthesis initiates during seed filling, although it exhibits desynchronization between both varieties. We identified 10,153 Differentially Expressed Genes (DEGs) across all comparisons. The KEGG pathway 'Flavonoid biosynthesis' showed enrichment of induced DEGs in Negro Argel (PV172), consistent with the accumulation of delphinidin, petunidin, and malvidin hexosides in their seeds, while catechin glucoside, procyanidin and kaempferol derivatives were predominantly detected in Coscorrón (PV24). Furthermore, while the flavonoid pathway was active in both varieties, our results suggest that enzymes involved in the final steps, such as ANS and UGT, were crucial, inducing anthocyanin formation in Negro Argel. Additionally, during active anthocyanin biosynthesis, the accumulation of reserve proteins or those related to seed protection and germination was induced. These findings provide valuable insights and serve as a guide for plant breeding aimed at enhancing the health and nutritional properties of common beans.

Ultrasound-assisted extraction of anthocyanins from grape pomace using acidified water: Assessing total monomeric anthocyanin and specific anthocyanin contents.

This study aimed to optimize the ultrasound-assisted extraction (UAE) of anthocyanins from oven-dried and freeze-dried Vitis labrusca grape pomace, using acidified water as the solvent. The effects of power density (8.3-16.7 W/mL), pulse interval (0-2 s), and extraction time (1-5 min) on both total and specific anthocyanins were investigated. The findings suggested that acidified water can be a viable alternative to conventional solvents and that oven drying was an effective method for drying the pomace. Using response surface methodology, the study identified power density and extraction time as key factors influencing total anthocyanin content, with extracts reaching contents up to 2.56 mg/g. The analysis using LC-MS identified 14 anthocyanins, while NMR quantified 3 and malvidin diglucoside was generally the most abundant. However, higher power and longer extraction times were found to reduce its content while increasing malvidin monoglucoside content, suggesting ultrasound-induced anthocyanin hydrolysis. In conclusion, this study presents a sustainable method for extracting anthocyanins using acidified water, contributing to the valorization of Vitis labrusca grape pomace for industrial use.

Green Synthesis of Silver Nanoparticles from Anthocyanin Extracts of Peruvian Purple Potato INIA 328-Kulli papa.

In this work, AgNPs were synthesized using an anthocyanin extract from Peruvian purple potato INIA 328-Kulli papa. The anthocyanin extract was obtained through a conventional extraction with acidified ethanolic aqueous solvent. This extract acted as both a reducing and stabilizing agent for the reduction of silver ions. Optimization of synthesis parameters, including pH, reaction time, and silver nitrate (AgNO3) concentration, led to the optimal formation of AgNPs at pH 10, with a reaction time of 30 min and an AgNO3 concentration of 5 mM. Characterization techniques such as X-ray diffraction (XRD) and dynamic light scattering (DLS) revealed that the AgNPs had a crystallite size of 9.42 nm and a hydrodynamic diameter of 21.6 nm, with a zeta potential of -42.03 mV, indicating favorable colloidal stability. Fourier Transform Infrared (FTIR) analysis confirmed the presence of anthocyanin functional groups on the surface of the AgNPs, contributing to their stability. Furthermore, the bacterial activity of the AgNPs was evaluated by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). For E. coli, the MIC was 0.5 mM (0.05 mg/mL) and the MBC was 4.5 mM (0.49 mg/mL). Similarly, for S. aureus, the MIC was 0.5 mM (0.05 mg/mL) and the MBC was 4.0 mM (0.43 mg/mL). These results highlight the potential benefits of AgNPs synthesized from Peruvian purple potato anthocyanin extract, both in biomedical and environmental contexts.

Efficient Anthocyanin Recovery from Black Bean Hulls Using Eutectic Mixtures: A Sustainable Approach for Natural Dye Development.

There is a growing interest in exploring new natural sources of colorants. This study aimed to extract anthocyanins from broken black bean hulls (Phaseolus vulgaris L.) by modifying water with a eutectic mixture (choline chloride:citric acid (ChCl:Ca)). Ultrasound-assisted extraction (UAE) was employed and optimized in terms of temperature (30-70 °C), ultrasound power (150-450 W), and eutectic mixture concentration in water (1-9% (w/v)), resulting in an optimal condition of 66 °C, 420 W, and 8.2% (w/v), respectively. The main quantified anthocyanins were delphinidin-3-O-glycoside, petunidin-3-O-glycoside, and malvidin-3-O-glycoside. The half-life of the anthocyanins at 60 °C increased twelvefold in the eutectic mixture extract compared to the control, and when exposed to light, the half-life was 10 times longer, indicating greater resistance of anthocyanins in the extracted eutectic mixture. Additionally, the extracts were concentrated through centrifuge-assisted cryoconcentration, with the initial cycle almost double the extract value, making this result more favorable regarding green metrics. The first concentration cycle, which showed vibrant colors of anthocyanins, was selected to analyze the color change at different pH levels. In general, the technology that uses eutectic mixtures as water modifiers followed by cryoconcentration proved to be efficient for use as indicators in packaging, both in quantity and quality of anthocyanins.

Targeted Anthocyanin Profiling of Fruits from Three Southern Highbush Blueberry Cultivars Propagated in Colombia.

The blueberry, a deciduous shrub in the Ericaceae family, is celebrated for its delightful flavor, sweetness, and abundance of anthocyanins and antioxidants, qualities that have garnered significant attention for their potential health benefits. Blueberries grown in diverse environments and exhibit varied anthocyanin profiles, often influenced by factors such as altitude and climate. Varietal groups worldwide have been bred and categorized based on their growth habits and specific cold requirements, particularly with southern highbush cultivars thriving in temperate climates, demonstrating tolerance to higher altitudes or cooler climates-a result of hybridizations involving various Vaccinium species. In the Colombian Andes, southern highbush blueberries thrive in unique high-altitude conditions, leading to exceptional quality due to the region's cool climate and specific soil characteristics. In this context, this study aimed to chemically characterize and differentiate three southern highbush blueberry cultivars (i.e., 'Biloxi,' 'Legacy' and 'Sharpblue') cultivated in a Colombian Andean plateau and compare them to three commercially available highbush blueberries. This comprehensive evaluation involved examining total phenols, flavonoids, anthocyanin content, and DPPH· free-radical scavenging capacity, as well as conducting anthocyanin-targeted profiling via HPLC-DAD-HRMS. Through supervised multivariate analyses such as sPLS-DA, this study delved into the pattern recognition of those anthocyanins that could potentially serve as markers for quality and cultivar-related chemical trait determination. These findings locate blueberry-derived anthocyanins in a metabolic context and afford some insights into southern highbush blueberry cultivar differentiation to be used for further purposes.

Nutritional, Fatty Acids, (Poly)phenols and Technological Properties of Flower Powders from Fuchsia hybrida and Alcea rosea.

Fuchsia hybrida (pena pena) and Alcea rosea L. (malvagoma) are predominant flowers in the "Horchata" infusion, a traditional beverage in southern Ecuador, to which some medicinal properties are attributed. However, there is very little published information about these two flower species. The current study aimed to obtain two dehydrated powders of these flowers and to determine their chemical composition, physicochemical and technological properties, polyphenols, and fatty acids profile. In both powdered flowers, carbohydrates predominated, with a significant content of dietary fiber and fructose. The fat content was low, mainly comprising polyunsaturated fats (62% pena pena and 52% malvagoma), with a significant presence of omega-3 (C18:3n-3,6,9) and omega-6 (C18:2n-6,9) fatty acids, showing a better n-6/n-3 balance in the malvagoma flowers. Pena pena flowers are highlighted by high anthocyanin and ellagic acid amounts, whereas malvagoma contains a high content of flavanones. In conclusion, the studied powder flowers, could be used in the formulation of new foods or as source of anthocyanins as food colorants.

Delphinidins from Maqui Berry (Aristotelia chilensis) ameliorate the subcellular organelle damage induced by blue light exposure in murine photoreceptor-derived cells.

BACKGROUND: Blue light exposure is known to induce reactive oxygen species (ROS) production and increased endoplasmic reticulum stress, leading to apoptosis of photoreceptors. Maqui berry (Aristotelia chilensis) is a fruit enriched in anthocyanins, known for beneficial biological activities such as antioxidation. In this study, we investigated the effects of Maqui berry extract (MBE) and its constituents on the subcellular damage induced by blue light irradiation in mouse retina-derived 661W cells. METHODS: We evaluated the effects of MBE and its main delphinidins, delphinidin 3-O-sambubioside-5-O-glucoside (D3S5G) and delphinidin 3,5-O-diglucoside (D3G5G), on blue light-induced damage on retinal cell line 661W cells. We investigated cell death, the production of ROS, and changes in organelle morphology using fluorescence microscopy. The signaling pathway linked to stress response was evaluated by immunoblotting in the whole cell lysates or nuclear fractions. We also examined the effects of MBE and delphinidins against rotenone-induced mitochondrial dysfunction. RESULTS: Blue light-induced cell death, increased intracellular ROS generation and mitochondrial fragmentation, decreased ATP-production coupled respiration, caused lysosomal membrane permeabilization, and increased ATF4 protein level. Treatment with MBE and its main constituents, delphinidin 3-O-sambubioside-5-O-glucoside and delphinidin 3,5-O-diglucoside, prevented these defects. Furthermore, MBE and delphinidins also protected 661W cells from rotenone-induced cell death. CONCLUSIONS: Maqui berry may be a useful protective agent for photoreceptors against the oxidative damage induced by exposure to blue light.

Anthocyanin-enriched extract from Ribes nigrum inhibits triglyceride and cholesterol accumulation in adipocytes.

Aim: Obesity is a chronic pathology of epidemic proportions. Mature adipocytes from a 3T3-L1 cell line were used as in vitro obesity model to test different bioactive compounds. We aim to evaluate cassis (Ribes nigrum) extract antioxidant activity and its antiadipogenic effect on mature adipocytes. Results: We produced an extract by using enzyme that combines cellulase and pectinase; we obtained high yield of the bioactive compound anthocyanin. Extract showed high antioxidant capacity. We conducted in vitro assays by adding the extract to adipocytes culture medium. Extract reduced intracellular levels of triglyceride by 62% and cholesterol by 32%. Conclusion: Enzymatic extract's high antioxidant activity was likely attributable to its high concentration of anthocyanin. This extract inhibits lipid accumulation in adipocytes.

Obesity is a disease all over the world. By 2030, nearly 20% of adults are predicted to be obese. The consumption of processed foods is related to obesity in some countries such as Argentina. More natural food is needed. There are many different anti-obesity medicines but there is no good one to lose weight. We took extracts from cassis fruits and tested whether they could decrease fats like cholesterol within fat cells. We found that these extracts could successfully reduce the fat levels in the cells. Our results indicate that natural compounds like cassis fruit extract may be helpful in preventing future obesity epidemics.

Obtaining and characterizing polyphenol extracts based on anthocyanins from Melinis minutiflora inflorescences and Plinia cauliflora fruits and application in gelatins.

Anthocyanins are a class of compounds potentially used as food dyes. Thus, this study aimed to obtain and characterize natural extracts from Melinis minutiflora inflorescence (M), Plinia. cauliflora peel (JP) and P. cauliflora peel and seeds (JPS) and apply them as natural food dyes in gelatins. The extracts did not show statistically significant differences in pH values and water activity. The M and JPS extracts showed similar values of anthocyanins and total phenolic compounds and were higher than those from the JP extract. The M and JPS extracts showed a bathochromic effect, which was not observed for the JP extract. The bathochromic effect may indicate a possible complexation of anthocyanins. The color composition analysis revealed that the JP extract has a higher absorbance at a wavelength of 520 nm, indirectly suggesting the presence of more monomeric anthocyanins in its composition. The extract application test in gelatin did not change the texture properties of the gelatins. In addition, our findings revealed that the JPS extract had the best color stability after ten days of analysis, indicating that anthocyanin complexation with the phenolic compounds of P. cauliflora seeds contributed more effectively to anthocyanin stability in the model used.

Bioactive Compounds and Antioxidant Activity in Seeds of Bred Lines of Common Bean Developed from Interspecific Crosses.

Knowledge is limited about the level of bioactive compounds and antioxidant activity of seeds from bred lines of common beans developed from interspecific crosses using four different Phaseolus species (P. vulgaris L., P. coccineus L., P. acutifolius A. Gray. Gray., and P. dumosus). In this study, differences in the nutritional quality of seeds among 112 bean genotypes were evaluated by measuring the levels of phenolic compounds, pigments, antioxidant activity, and sugars. The bean genotypes were grown under high temperatures and acid soil conditions in the Amazon region of Colombia. Five typology groups of bean genotypes were identified based on the level of bioactive compounds and their functional capacity: (1) highly bioactive and functional (HBF); (2) moderately bioactive and functional (MBF); (3) moderate antioxidant content with pigment influence (MACP); (4) moderately antinutritional with limited antioxidant potential (MALAP); and (5) antinutritional, low bioactive, and functional (ALBF). We developed a nutritional quality index (NQI) with values ranging from 0 to 1 based on the nutritional and anti-nutritional balance of each genotype and the higher values of the NQI of a genotype indicating greater nutritional quality. We found three interspecific bred lines (SER 212, SER 213, and RRA 81), with NQI values higher than 0.8. These three lines belong to the typology group of HBF. The superior nutritional quality of these three interspecific bred lines is attributed to a greater level of bioactive compounds and antioxidant capacity. These three bred lines may serve as useful parents to develop nutritionally superior and stress-resilient beans from bean breeding programs. Further research is needed to explore the role of testa color in improving the nutritional quality of seeds of common bean genotypes grown under different climatic conditions.

Stability of Phenolic Compounds, Antioxidant Activity and Color Parameters in Colored-Flesh Potato Chips.

Potato (Solanum tuberosum) chips are the most consumed snacks worldwide today. Colored potato chips prepared from potato cultivars with red and purple flesh are a novel alternative to traditional potato chips because of their higher phenolic compound content, such as anthocyanins and hydroxycinnamic acid derivatives (HCADs), which might make these chips healthier compared with traditional chips. There is little information on the stability of these compounds. In this study, the nutritional value of these chips was evaluated by determining phenolic profiles, antioxidant activity and color parameters with liquid chromatography diode array and mass spectrometry detection (HPLC-DAD-ESI-MS/MS) and spectrophotometric methods during storage for four months. Five anthocyanins and three HCADs were detected, with the latter compounds being the most abundant, with concentrations on average between the first (97.82 mg kg-1) and the last (31.44 mg kg-1) week of storage. Similar trends were observed in antioxidant activity and stability, with the CUPRAC method showing the highest response among all the methods employed. The color indices were stable throughout the storage time. Based on these results, colored-flesh potato chips are an optimal alternative for consumption because of their high retention of phenolic compounds and antioxidant activity during storage, providing potential benefits to human health.

Flowered Grain Quality and Phytochemical Content of Non-Conventional Maize Hybrids from the Mexican Subtropics across Three Growing Cycles.

Development of non-conventional hybrids responds to the demand for the Elotes Occidentales land-race for production of pozole. The effect of growing cycle (2019, 2020, and 2021) on physical characteristics, flowered grain quality, and phytochemical content of two non-conventional hybrids of pozolero maize, as well as the effect of the presence or absence of pedicel, type of pollination (open and controlled, 2019), and parents (female and male, 2020) on flowered grain quality and content of phytochemical compounds, were evaluated. Size, hardness, color, total phenols, and anthocyanins in unprocessed grain were determined. Yield, volume, and puncture force were measured in flowered grain. Results were analyzed with a factorial arrangement in a completely randomized design. There were significant differences (p ≤ 0.05) in most of the variables studied by effect of crop cycle and hybrid. Non-conventional hybrids had large grains (40 g 100 grains-1), soft endosperm (flotation index > 60), pink-purple color, and phenol and anthocyanin contents similar to those reported for the Elotes Occidentales land-race. The presence or absence of the pedicel did not affect flowered grain quality. Controlled pollination favored anthocyanin synthesis. The female parent determined the anthocyanin content of non-conventional hybrids. Thermal processing reduced anthocyanins by 60%; however, they leached into the flowering broth, so that the pozole made from non-conventional hybrids can have improved nutraceutical value, relative to that of pozole made with Cacahuacintle land-race.

Comparative Assessment of Antioxidant Activity and Functional Components of Chionanthus virginicus and Chionanthus pubescens from the Andean Region of Ecuador.

The present study aims to provide information about the antioxidant capacity and secondary metabolites from different plant parts of two species that are grown in Ecuador: Chionanthus pubescens (the Ecuadorian national tree), and Chionanthus virginicus (the fringe tree-endemic to the United States of America and adapted to Ecuador's physiographical and ecological conditions). These two species have still not been investigated for these characteristics. A comparative estimation of the antioxidant activities between the leaf, fruit, and inflorescence extracts was performed. In the quest for new medicines, the extracts were analyzed for phenolic, anthocyanin, and flavonoid content. A slight difference was observed between C. pubescens and C. virginicus flowers, the highest antioxidant activity being found in the C. pubescens leaf (DPPH IC50 = 62.8866 mg/mL, ABTS IC50 = 55.852 mg/mL, and FRAP IC50 = 2.8466 g/mL). Our results showed correlations between antioxidant activity, total phenolic content, and flavonoids. This study confirmed that the C. pubescens leaves and fruits from the Andean region of Ecuador represent a good source of antioxidants, especially due to the presence of a high content of phenolic compounds (homovanillic acid, 3,4 dimethoxyphenylacetic acid, vanillic acid, gallic acid, etc.) as determined by the HPLC-DAD method.

Anthocyanin-rich black carrot (Daucus carota ssp. sativus var. atrorubens Alef.) and red cabbage (Brassica oleracea) extracts incorporated biosensor for colorimetric detection of Helicobacter pylori with color image processing.

In this work, we developed novel colorimetric biosensors consisting of anthocyanin-rich either black carrot (Daucus carota ssp. sativus var. atrorubens Alef.) or red cabbage (Brassica oleracea) extracts for rapid, sensitive, and economic detection of Helicobacter pylori (H. pylori). We comparatively prepared two test solutions as biosensors including anthocyanin-rich black carrot extract (Anth@BCE) and red cabbage extract (Anth@RCE), both of which fixed to pH 2.5 and investigated their colorimetric responses based on electronic structure and electron density of anthocyanins. We successfully used anthocyanin-rich BCE and RCE as natural pH indicators in detection of H. pylori and introduced their advantages like non-toxicity, easy accessibility, and high stability compared to synthetic indicators. The BCE and RCE tests gave the best color change in the presence of 103 CFU/mL (at 60 min) and 104 CFU/mL (at 75 min) H. pylori suspensions prepared in an artificial gastric fluid. The limit of detection was down to 10 CFU/mL for RCE and BCE tests by increasing incubation time (≥ 5 h). We further made an additional study that color differences in the colorimetric responses observed by naked eyes were supported by digital image processing with RGB (Red Green Blue) and Delta-E (ΔE) analysis. It is confirmed that results evaluated by naked eyes and digital image processing are well consistent with each other. These findings proposed that these colorimetric tests can be implemented to pH dependent detection of various microorganisms and can be effectively transferred from laboratory work to clinics in the near future.

Bioactive Compounds and Antioxidant Activity in the Fruit of Rosehip (Rosa canina L. and Rosa rubiginosa L.).

Rosehips (Rosa spp., Rosaceae) are wild rose bushes with more than 100 species. Its fruits vary in colour and size, depending on the species, and are recognised for their nutritional characteristics. Ten samples of Rosa canina L. and Rosa rubiginosa L. fruits were collected at different geographical points from Southern Chile. Nutrients such as crude protein and minerals and functional properties such as phenolic compounds, ascorbic acid, and also antioxidant activities were evaluated by HPLC-DAD-ESI-MS/MS. The results revealed a high content of bioactive compounds, primarily ascorbic acid (6.0 to 8.2 mg g-1 fresh weight (FW)), flavonols (427.9 ± 0.4 µg g-1 FW) and antioxidant activity. We established a relationship between the antioxidant activity using Trolox equivalent antioxidant capacity (TEAC), cupric reducing antioxidant capacity (CUPRAC) and 2,2-diphenyl radical (DPPH) methods and the concentration of uncoloured compounds, such as flavonols and catechin. This antioxidant activity was primarily associated with the samples from Gorbea, Lonquimay, Loncoche, and Villarrica localities, and all of them were of the species Rosa rubiginosa L. The results here obtained represent novel information of rosehip fruits. In this sense, the reported information about compounds and antioxidant activities in rosehip fruits allowed us to continue new lines of research in relation to the potential formulation of new functional foods and also in the treatment and/or prevention of some diseases.

Características físico-químicas e sensoriais do queijo prato com embalagem inteligente / Physico-chemical and sensory characteristics of "prato"cheese with intelligent packaging

O objetivo da pesquisa foi comparar as características físico-químicas e sensoriais de queijos tipo prato, produzidos no Laboratório de Produtos de Origem Animal do Instituto Federal Goiano ­ Campus Rio Verde com o queijo prato industrial e avaliar a aceitabilidade de embalagens inteligentes preparadas com soro de leite e antocianina da casca de jabuticaba. Os queijos prato industriais foram adquiridos no mercado local. Foram realizadas análises de teor de água, extrato seco, cinza, pH, acidez, proteína, lipídios, gordura extrato seco, cor (L*, a*, b*, Chroma e Hue), textura, perfil do consumidor e intenção de compra. Os queijos tipo prato produzidos no laboratório apresentaram maior teor de umidade e pH em comparação com os queijos industriais; no entanto, na análise de cor por colorimetria, não houve diferença entre os parâmetros analisados. Nas análises de cinzas, proteína, lipídios e acidez, os queijos industriais apresentaram maiores valores em relação aos análogos produzidos no laboratório, enquanto maiores teores de gordura extrato seco foram determinados nos queijos análogos quando comparados aos queijos industriais. Por fim, a análise de textura demonstrou que os queijos industriais são mais firmes que seus análogos.

This research aimed to compare the physico-chemical and sensory characteristics of cheeses type 'prato' produced in the Laboratory of Products of Animal Origin of the Goiano Federal Institute ­ Green River Campus with 'Prato' industrial cheese and evaluate the acceptability of intelligent packings prepared with whey and anthocyanin from jabuticaba peel. Industrial 'prato' cheeses were acquired from the local market. Analyses of water content, dry extract, ash, pH, acidity, protein, lipids, dry extract fat, color (L*, a*, b*, Chroma and Hue), texture, consumer profile, and purchase intention. Cheeses type 'prato' produced in the laboratory presented higher in moisture levels and pH compared to industrial cheeses; however, in the color analysis by colorimetry there was no difference between the analyzed parameters. For analyses of ash, protein, lipids, and acidity, the industrial cheeses showed higher values in relation to the analogs produced in the laboratory, while higher contents of dry extract fat were determined in the analog cheeses when compared to the industrial cheeses. Finally, the texture analysis demonstrated that the industrial cheeses are firmer than their analogs.

Stabilization of Anthocyanins from Coffee (Coffea arabica L.) Husks and In Vivo Evaluation of Their Antioxidant Activity.

Coffee (Coffea arabica L.) is one of the most popular and widely consumed products throughout the world, mainly due to its taste, aroma, caffeine content, and natural antioxidants. Among those antioxidants, anthocyanins are one of the most important natural pigments, which can be found in coffee husks. It is widely known that anthocyanins have multiple health benefits partially linked to their antioxidant properties. However, anthocyanins have low stability and are sensitive to all types of changes. In order to prevent its degradation, anthocyanins can be stabilized with nanoparticles. Thus, the main objective of this study was to evaluate the stability of the anthocyanins extracted from coffee husks, using three different extracting agents (ethanol, methanol, and water) and stabilizing them through conjugation with zinc oxide nanoparticles. The anthocyanins extracts were mainly composed of cyanidin-3-rutinoside (97%) and the total phenolic compounds of the fresh extracts were 458.97 ± 11.32 (methanol), 373.53 ± 12.74 (ethanol), and 369.85 ± 15.93 (water) mg GAE/g. On the other hand, the total phenolic compounds of the nanoparticle-anthocyanin conjugates underwent no significant changes after stabilization as the major loss was less than 3%. Furthermore, the percentage of anthocyanins' degradation was less than 5% after 12 weeks of storage. On top of that, fresh anthocyanin extracts and anthocyanin-nanoparticle conjugates exhibited a strong protective effect against oxidative stress and increased the survival rate of Caenorhabditis elegans.

Novel Roles of SPATULA in the Control of Stomata and Trichome Number, and Anthocyanin Biosynthesis.

The bHLH transcription factor SPATULA (SPT) has been identified as a regulator during different stages of Arabidopsis development, including the control of leaf size. However, the mechanism via which it performs this function has not been elucidated. To better understand the role of SPT during leaf development, we used a transcriptomic approach to identify putative target genes. We found putative SPT target genes related to leaf development, and to stomata and trichome formation. Furthermore, genes related to anthocyanin biosynthesis. In this work, we demonstrate that SPT is a negative regulator of stomata number and a positive regulator of trichome number. In addition, SPT is required for sucrose-mediated anthocyanin biosynthesis.

Organic-Inorganic Hybrid Pigments Based on Bentonite: Strategies to Stabilize the Quinoidal Base Form of Anthocyanin.

Anthocyanins are one of the natural pigments that humanity has employed the most and can substitute synthetic food dyes, which are considered toxic. They are responsible for most purple, blue, and red pigment nuances in tubers, fruits, and flowers. However, they have some limitations in light, pH, oxygen, and temperature conditions. Combining biomolecules and inorganic materials such as clay minerals can help to reverse these limitations. The present work aims to produce materials obtained using cetyltrimethylammonium bromide in bentonite clay for incorporation and photostabilization of anthocyanin dye. Characterizations showed that the organic molecules were intercalated between the clay mineral layers, and the dye was successfully incorporated at a different pH. Visible light-driven photostability tests were performed with 200 h of irradiation, confirming that the organic-inorganic matrices were efficient enough to stabilize the quinoidal base form of anthocyanin. The pigment prepared at pH 10 was three-fold more stable than pH 4, showing that the increase in the synthesis pH promotes more stable colors, probably due to the stronger intermolecular interaction obtained under these conditions. Therefore, organobentonite hybrids allow to stabilize the fragile color coming from the quinoidal base form of anthocyanin dyes.