Search Results (120)

Herbs are valued for their antioxidant richness and traditional use in cuisine and medicine. This study analysed wild herbs (e.g., Achillea, Lamium) and cultivated spices (Salvia, Artemisia) for their bioactive compounds. It was found that antioxidant profiles varied notably among species, even within the same family. Helichrysum italicum and Salvia officinalis had the highest polyphenol levels, while Achillea millefolium and Ocimum basilicum had the lowest. Total polyphenols did not always correlate with antioxidant activity. For instance, Petroselinum hortense and Salvia rosmarinus showed high antioxidant activity despite low polyphenol levels, whereas Levisticum officinale and Artemisia dracunculus combined both. Mentha spicata, M. x citrata, Origanum vulgare, and S. officinalis were rich in carotenoids, while H. italicum showed high α-carotene but low levels of other carotenoids. Most Lamiaceae accumulated a high amount of chlorophylls and polyphenols. Cultivated herbs like M. spicata, M. x citrata, and S. officinalis exhibited stronger and more diverse properties than wild species. It can be concluded that taxonomy alone does not predict antioxidant potential. The differences observed may be attributed to species-specific metabolic pathways, ecological adaptations, or environmental factors influencing phytochemical expression. These findings highlight the importance of conducting species-level screenings in the search for plant-derived antioxidants with potential therapeutic applications. Full article

Biomass-derived growth stimulants are widely recognized as green and economical solutions that can significantly enhance microalgae culture efficiency and optimize the biomanufacturing process of target products. In this paper, we investigated the effect of ethanol synergized with guaiacol (GA) on biomass and β-1,3 glucan accumulation in edible microalgae, namely Euglena gracilis. The ethanol-induced mixotrophic mode significantly increased biomass and paramylon production by 12.68 and 6.43 times, respectively, compared to the autotrophic control group. GA further exerted toxic excitatory effects (hormesis) on top of ethanol mixotrophic nutrition. At the optimal concentration of 10 mg·L⁻¹ GA, chlorophyll a, carotenoids, and paramylon production increased by 8.96%, 11.75%, and 16.67%, respectively, compared to the ethanol-treated group. However, at higher concentrations, the biomass and paramylon yield decreased significantly. This study not only establishes an effective combinatorial strategy for enhancing paramylon biosynthesis but also provides novel insights into the hormesis mechanism of phenolic compounds in microalgae cultivation. The developed approach demonstrates promising potential for sustainable production of high-value algal metabolites while reducing cultivation costs, which could significantly advance the commercialization of microalgae-based biorefineries in food and pharmaceutical industries. Full article

Global fruit production is excessive, and fruit wine is a significant outcome of fruit processing. The pigment in fruit wine gives it a vibrant color and affects its quality, taste, and marketing. The pigments in fruit wines are commonly divided into three categories: anthocyanins, carotenoids, and chlorophylls. They are naturally synthesized pigments in plants that undergo complex biochemical changes that eventually tend to be stable in mature fruit wine, showing the color properties desired by consumers. Under normal circumstances, pigment molecules are unstable and have isomers, which makes it difficult to accurately identify and control them. In addition, biochemical changes produce a series of chemical derivatives that affect bioavailability and biological functions. This review summarizes the chemical basis, formation process, influencing factors, identification techniques, bioavailability, and bioactivity of fruit wine pigments, providing an important reference for the utilization of fruit resources and the development of high-quality fruit wine products. Full article

Oxidative stress and its relation to the onset of several chronic diseases have been increasingly highlighted in recent years. In parallel, there has been an increasing interest in the antioxidant properties of phytochemicals. Phytochemicals are products of plant secondary metabolism, including structural polysaccharides, unsaturated fatty acids, pigments (chlorophylls, carotenoids, and anthocyanins), or phenolic compounds. Phytochemicals can be obtained from lower and higher plants, their fruits, and even from macro- or microalgae. Their diverse structural features are linked to different beneficial effects through various molecular mechanisms, contributing to disease prevention. Beyond antioxidant activity, many phytochemicals also display anti-inflammatory, antidiabetic, anti-obesity, and neuroprotective effects, which can be intertwined. Beyond these, other natural antioxidants can also be obtained from animal, fungal, and bacterial sources. Thus, a wide range of antioxidants have the potential to be used as nutraceuticals with chemopreventive effects on the onset of various diseases related to antioxidant stress. Given their enormous structural and sourcing diversity, the present work provides an updated insight into the therapeutic and preventive potential of plant-derived antioxidants and nutraceuticals. Full article

The rising demand for alternative solutions to diabetes mellitus has prompted significant interest in the exploration of plant-derived anti-diabetic compounds, especially within a circular economy framework that seeks sustainable and profitable reuse options. In this context, red (RSGO) and white (WGSO) grape seed oils, by-products of Sicilian vineyards, were prepared, analyzed for their fatty acid, polyphenol, carotenoid, and chlorophyll content, and evaluated for their glucose-lowering ability on HepG2 cells. Utilizing cytochemical techniques, flow cytometry, and protein blotting, we explored the effects of non-toxic oil dilutions on (i) glycogen storage, (ii) glucose consumption/uptake, (iii) GLUT-2, GLUT-4, and hepatocyte nuclear factor-1α (HNF1α) expression levels, and (iv) AMP-activated protein kinase (AMPK), insulin receptor substrate-1 (IRS-1), AKT, and PKCζ phosphorylation states, which are involved in insulin-mediated and -independent regulation of GLUT-4 membrane exposure. RGSO and WGSO, despite adopting slightly varying molecular strategies, were both proven to be effective stimulators of glucose absorption and glycogenesis. Specifically, RSGO promoted GLUT-2 and GLUT-4 up-regulation, whereas the WGSO-induced effect was associated with an increase in GLUT-4 levels alone. Moreover, the oils activated both pathways responsible for GLUT-4 translocation. Therefore, these wine-making residues have substantial potential as anti-diabetic solutions, holding promise for integration into the biomedical and food sectors. Full article

Phycobiliproteins and pigments derived from cyanobacteria hold significant potential for diverse applications in the food, pharmaceutical, and chemical industries. The filamentous cyanobacterium Anabaena cylindrica serves as a valuable resource for extracting these compounds. This study develops a simplified, safe, and cost-effective extraction method that eliminates toxic solvents and minimizes processing steps. This makes the method applicable for all users and allows the easy integration of the extraction into biorefinery concepts in which the biomass is to be used as a fertilizer, for example. Utilizing salts such as ammonium sulfate and calcium chloride (15 gL⁻¹ each) enables the effective extraction of phycocyanin (PC) and allophycocyanin, achieving a PC concentration of 192.34 $\mathrm{mg}{\mathrm{g}}_{\mathrm{CDW}}^{-1}$ and 209.44 $\mathrm{mg}{\mathrm{g}}_{\mathrm{CDW}}^{-1}$, respectively. Ethanol was introduced as a less toxic alternative to methanol for pigment extraction, increasing chlorophyll a and carotenoid recovery by 21% and 37%, respectively. Full article

The current research aims to monitor the physicochemical changes in various varieties of extra virgin olive oils (EVOOs) supplemented with exogenous polyphenolic extract from olive fruit, enriched with hydroxytyrosol (HTyr) and its derivatives, compared to numerous refined olive oils, sunflower oil, and high oleic sunflower oil under different deep-frying conditions (170–210 °C for 3 to 6 h, with/without added HTyr. Acidity, K₂₃₂, K₂₇₀, ∆K, peroxide value (PV), anisidine value (AnV), TOTOX, refractive index (RI), carotenoids, chlorophyll, and antioxidant capacity using DPPH (2,2-diphenyl-1-picrylhydrazyl) approach were evaluated. The results show that EVOO varieties generally exhibit lower acidity and thermal degradation compared to refined olive oils, particularly when deep-fried at 170 °C for 3 h with exogenous HTyr (the best treatment). Royuela, Koroneiki, Empeltre, Manzanilla, and Arbosana EVOO varieties demonstrated lower K₂₃₂ values (1.36, 1.67, 1.79, 1.82, and 1.81, respectively). Under optimal deep-frying conditions, all EVOO varieties fell within the standard K₂₃₂ limit for EVOO (≤2.5), except for Cornicabra. Regarding K₂₇₀, only Royuela (0.11) and Manzanilla (0.22) were below the standard limit of ≤0.22. These two varieties also exhibited the lowest ΔK values (0.00). The findings further revealed that Royuela, Koroneiki, and Manzanilla had the lowest TOTOX values, with 20.76, 23.38, and 23.85, respectively. Moreover, Koroneiki and Arbosana had the highest carotenoid ratios, with values of 17.5 mg/kg and 13.7 mg/kg, respectively. Koroneiki, Arbosana, and olive oil 1° also displayed the highest chlorophyll concentrations, with values of 50.2, 53.7, and 47.5 mg/kg, respectively. Furthermore, the findings from the best deep-frying treatment indicated that all olive oil categories exhibited high scavenging radical activity toward DPPH, even in refined olive oil categories and low-quality original olive oil due to the addition of HTyr. In conclusion, deep-fried EVOOs enriched with HTyr at 170 °C/3 h are thermally stable, exhibiting low hydrolysis, low oxidation, higher antioxidant potential, and stable chlorophyll and carotenoid levels. The addition of HTyr to deep-frying oils not only enhances the health benefits of EVOO, supporting EFSA health claims but also acts as a promising stabilizer for the olive oil industry, particularly under high-temperature processing conditions over prolonged periods. This highlights its potential for industrial use as a natural alternative to synthetic antioxidants, not only for olive oil but also for other edible oils, with practical applications in the food industry to improve the quality and stability of frying oils. Full article

Industrial hemp (Cannabis sativa L.) is a versatile and sustainable multipurpose plant for agroecology services and a zero-waste circular economy. While the focus has traditionally been on primary products like fiber and seeds, nowadays there is an increasing awareness of the potential value of the by-products generated during hemp cultivation and processing. This article explores various methods of valorizing industrial hemp wastes, focusing on their mineral and biochemical composition, highlighting the benefits of utilizing what was once considered a mere by-product. The apical and the basal leaves of 12 industrial hemp varieties, six monoecious, and six dioecious, representing the main by-product of fiber supply chain, were assessed for their mineral (N, K, Na, Ca; Mg, Cu, Mn, Fe, and Zn), chlorophyll, carotenoids, and total soluble phenols contents, as well as for their antioxidant activity. The same parameters were also evaluated in the inflorescences; the main waste was derived from both hemp fiber and seed harvesting, which were collected at three stages of flower development for four selected genotypes, together with the yield and chemical composition of their essential oils. Differences in the evaluated parameters among genotypes and tissues were highlighted, showing the potential for diversifying the utilization of industrial hemp wastes. The possible uses of these residual biomasses are discussed based on their composition. Full article

Carotenoids play a crucial role in the photosynthesis process in plants. Estimating and modeling the carotenoid content in Populus pruinosa leaves via high-spectrum technology is highly important for health status monitoring. This study involved acquiring the spectral reflectance of Populus pruinosa leaves at different times, followed by smoothing the data with a Savitzky—Golay filter, and then using methods such as first derivative (FD), continuous wavelet transform (CWT), and first-order derivative combined with continuous wavelet transform (CWT+FD), creating three spectral transformation methods. Two- and three-dimensional vegetation indices were then constructed in a unified manner. Two modeling methods, backpropagation neural network (BPNN) and support vector regression (SVR), were employed to estimate the leaf carotenoid density by combining the vegetation indices. The results show that after the spectral reflectance of the canopy of Populus pruinosa is processed by FD, CWT, and CWT+FD on the basis of SG smoothing, it can effectively highlight the spectral characteristics of Populus pruinosa leaves, and the local spectral absorption features are more significant. Compared with the three spectral preprocessing methods, the results showed that the correlation between the values processed by the FD + CWT method and the leaf carotenoid density is the highest. The constructed three-band vegetation index exhibited a 4.26% stronger correlation with carotenoid density than did the two-band vegetation index. Among the three-band index-based models, the SVR model outperforms the BPNN model. For chlorophyll density, the SVR model based on the three-band index processed using CWT+FD achieves the best performance. The coefficient of determination (R²) for the SVR model set was 0.782, the root-mean-square error (RMSE) was 0.022, and the relative percentage deviation (RPD) was 0.206. For the validation set, the (R²) value was 0.648, the RMSE was 0.023, and the RPD was 1.526, indicating the best model accuracy. Full article

Although the mechanisms underlying albino phenotypes have been examined in model plants and major crops, our knowledge of bract albinism is still in its infancy. Davidia involucrata, a relic plant called dove tree, is best known for the intriguing trait with a pair of white bracts covering the capitula. Here, comparative physiological, cytological, proteomic, and metabolomic analyses were performed to dissect the albinism mechanism of D. involucrata bracts. The bracts exhibited low chlorophyll and carotenoid contents, reduced photosynthetic efficiency, and impaired chloroplast structure. The severe deficiency of photosynthetic pigments and the substantial decrease in cuticle thickness made the bracts light-sensitive. In total, 1134 differentially expressed proteins (DEPs) were obtained between bracts and leaves. Pathway enrichment analysis of DEPs revealed that photosynthetic pigment biosynthesis and photosynthesis were suppressed, whereas protein processing in endoplasmic reticulum, flavonoid biosynthesis, and the ubiquitin–proteasome system (UPS) were activated in bracts. Strikingly, DEPs implicated in chloroplast development, including PPR and AARS proteins, were mainly down-regulated in bracts. We further investigated albinism-induced metabolic changes and detected 412 differentially abundant metabolites (DAMs). Among them, enhanced flavonoids accumulation can plausibly explain the role of bracts in pollinator attraction. Amino acids and their derivatives in bracts showed remarkably increased abundance, which might be causally linked to enhanced UPS function. Our work could lay foundations for understanding albinism mechanisms and adaptive significance of plant bracts and facilitate future utilization of D. involucrata resources. Full article

For photosynthesis, oxygenic phototrophic organisms necessarily contain not only chlorophylls but also carotenoids. Various carotenoids have been identified in algae and taxonomic studies of algae have been conducted. In this review, the relationship between the distribution of chlorophylls and carotenoids and the phylogeny of sea and freshwater oxygenic phototrophs, including cyanobacteria, red algae, brown algae, and green algae, is summarized. These phototrophs contain division- or class-specific chlorophylls and carotenoids, such as fucoxanthin, peridinin, diadinoxanthin, and siphonaxanthin. The distribution of β-carotene and its derivatives, including β-carotene, zeaxanthin, violaxanthin, neoxanthin, diadinoxanthin, fucoxanthin, and peridinin (β-branch carotenoids), are limited to divisions of a part of Rhodophyta, Cryptophyta, Heterokontophyta, Haptophyta, and Dinophyta. Meanwhile, the distribution of α-carotene and its derivatives, such as lutein, loroxanthin, and siphonaxanthin (α-branch carotenoids), are limited to divisions of a part of Rhodophyta (macrophytic type), Cryptophyta, Euglenophyta, Chlorarachniophyta, and Chlorophyta. In addition, carotenogenesis pathways are also discussed based on the chemical structures of carotenoids and the known characteristics of carotenogenesis enzymes in other organisms. The specific genes and enzymes for carotenogenesis in algae are not yet known. Most carotenoids bind to membrane-bound pigment-protein complexes, such as reaction centers and light-harvesting complexes. Some carotenoids function in photosynthesis and are briefly summarized. Water-soluble peridinin-chlorophyll a-protein (PCP) and orange carotenoid protein (OCP) have also been characterized. This review is a summary and update from the previous review on the distribution of major carotenoids, primary carotenogenesis pathways, and the characteristics of carotenogenesis enzymes and genes. Full article

The cold-pressed oil from Japanese quince seeds (JQSO) is notable for its favorable fatty acid profile, low oxidation rate, and bioactive compounds like antioxidants, sterols, and carotenoids. This study offers a detailed molecular-level physical characterization of JQSO and its minor components using differential scanning calorimetry (DSC), Langmuir monolayer studies, and various spectroscopic methods, including UV–vis absorption, fluorescence, and FTIR. DSC analysis identified five peaks related to triglyceride (TG) fractions and provided insights into the melting and crystallization behavior of JQSO. The Langmuir monolayer studies revealed high compressibility, indicative of superior emulsification properties. Viscoelastic modulus measurements suggested strong intermolecular interactions, contributing to the oil’s resilience under stress—an attribute typical of oils high in saturated or monounsaturated fatty acids. Spectroscopic methods confirmed the presence of phenolic acids, tocopherols, carotenoids, and their derivatives. The total fluorescence spectra highlighted prominent peaks at 290 nm/330 nm and 360 nm/440 nm, while the total synchronous fluorescence spectra revealed key excitation–emission regions (10–50 nm/300 nm and 40–140 nm/360 nm), corroborating the presence of tocopherols, phenols, polyphenols, flavones, and carotenoids. No evidence of chlorophyll was detected. The ATR-FTIR spectra validated the presence of fatty acids and triacylglycerols, emphasizing a high degree of esterification and the dominance of unsaturated fatty acids in oil structures. The methods used provided the opportunity to perform a label-free, fast, and reliable determination of the properties of JQSO. The findings confirmed that crude, cold-pressed JQSO retains its valuable bioactive components, aligning with previous research on its chemical and physical properties. Full article

Terpenoids, abundant and structurally diverse secondary metabolites in plants, especially in conifer species, play crucial roles in the plant defense mechanism and plant growth and development. In Pinus massoniana, terpenoids’ biosynthesis relies on both the mevalonate (MVA) pathway and the 2-methyl-D-erythritol-4-phosphate (MEP) pathway, with 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate synthase (HDS) catalyzing the sixth step of the MEP pathway. In this study, we cloned and conducted bioinformatics analysis of the PmHDS gene from P. massoniana. The results showed that PmHDS shares homology with HDS proteins from other species. Analysis of tissue expression patterns indicated that PmHDS exhibits the highest expression level in xylem tissue, followed by stems, with significantly lowest expression in the apical meristem. Treatment with NaCl, abscisic acid (ABA), ethylene (ETH), methyl jasmonate (MeJA), and salicylic acid (SA) upregulated the expression of PmHDS. Furthermore, we successfully cloned the PmHDS promoter (about 2220 bp) and integrated it into a GUS reporter vector, which resulted in GUS activity being observed in various tissues of Arabidopsis thaliana. Overexpression of the PmHDS gene in A. thaliana significantly increased the content of carotenoids, chlorophylls a and b, and related enzyme activities, as well as the levels of terpenoid derivatives such as cytokinin (CTK), gibberellic acid (GA), and ABA, thereby enhancing the resistance to those abiotic stresses. These findings suggest that PmHDS plays an important role in the terpenoid synthesis pathway. This study provides a theoretical basis for understanding the biosynthesis of terpenoids and lays a foundation for future research on the regulation of terpene synthesis and resistance in molecular breeding. Full article

Maize leaf blight (MLB), caused by the fungus Bipolaris maydis, is an important disease affecting maize production. In order to minimize the use of fungicides in agriculture, nutrient-based resistance inducers may become a promising alternative to manage MLB. The goal of this study was to investigate the potential of Semia^® (zinc (20%) complexed with a plant-derived pool of polyphenols (10%)) to hamper the infection of maize leaves by B. maydis by analyzing their photosynthetic performance and carbohydrate and antioxidative metabolism, as well as the expression of defense-related genes. Plants were sprayed with water (control) or Semia^® (referred to as induced resistance (IR) stimulus hereafter) and not inoculated or inoculated with B. maydis. The mycelial growth and conidium germination were significantly reduced by the IR stimulus in vitro. The MLB severity was significantly reduced by 76% for IR-stimulus-sprayed plants compared to plants from the control treatment. For infected and IR-stimulus-sprayed plants, the glucose, fructose, sucrose, and starch concentrations were significantly higher compared to inoculated plants from the control treatment. The activity levels of superoxide dismutase, ascorbate peroxidase, catalase, and glutathione reductase were significantly higher for the IR-stimulus-sprayed plants compared to plants from the control treatment. Less impairment on the photosynthetic apparatus (higher values for leaf gas exchange (rates of net CO₂ assimilation, stomatal conductance to water vapor, and transpiration) and chlorophyll a fluorescence (variable-to-maximum Chl a fluorescence ratio, photochemical yield, and yield for dissipation by down-regulation) parameters)) along with a preserved pool of chlorophyll a+b and carotenoids were noticed for infected and IR-stimulus-sprayed plants compared to infected plants from the control treatment. The defense-related genes IGL, CHS02, PR1, PAL3, CHI, and GLU were strongly up-regulated in the leaves of IR-stimulus-sprayed and infected plants compared to infected plants from the control treatment. These findings highlight the potential of using this IR stimulus for MLB management. Full article

Cyanobacterial blooms in lakes have increased in frequency and intensity over the past two decades, negatively affecting ecological and biogeochemical processes. This study focuses on the phytoplankton composition of Lake Maggiore, with a special emphasis on cyanobacteria detection through pigment composition. While microscopy is the standard method for phytoplankton identification, pigment-based methods provide broader spatiotemporal coverage. Between May and September 2023, five measurement campaigns were conducted in Lake Maggiore, collecting bio-geochemical and bio-optical data at 27 stations. The total Chlorophyll-a (TChl a) was measured, with concentrations ranging from 1.13 to 6.9 mg/m³. Phytoplankton pigment composition was analyzed using High-Performance Liquid Chromatography (HPLC) and the CHEMTAX approach was applied for phytoplankton classification. The results were cross-validated using Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and microscopic counts. Cyanobacteria were identified based on unique pigment markers, such as carotenoids. The HPLC-derived pigment classification results aligned well with both PCA and HCA and microscopic counts verified the accuracy of the pigment-based chemotaxonomy. The study demonstrates that pigment-based classification methods, when combined with statistical analyses, offer a reliable alternative for identifying cyanobacteria and other phytoplankton groups, with potential applications in support of remote sensing algorithm development. Full article