Carotenoid Pigments Research Articles

Degradation of Argan Oils Used in Edible and Cosmetic Applications After Exposure to UV Light.

This study investigates for the first time the effects of UV light exposure on the chemical composition of artisanal and cold-pressed culinary and cosmetic argan oils, as well as their quality and biological activities. We ascertained the oxidative stability of both types of oil through measurements of the peroxide value, acidity, UV-spectrophotometric indexes (E232 and E270), and iodine value. Over the course of eight hours at room temperature, the impact of UV light on the breakdown of tocopherols, polyphenols, chlorophylls, and carotenoid pigments was examined. The findings showed that during photo-oxidation, acidity, peroxide value, and particular extinction coefficients (E232 and E270) gradually increased. On the other hand, a decline in the content of polyphenols, tocopherols, carotenoid, and chlorophyll was noted. Interestingly, iodine levels failed to improve. Although after an eight-hour degradation, the physicochemical profile of Argan oils remained exceptional. DPPH• (1,1-Diphenyl-2-picrylhydrazyl) antioxidant activity tests showed a gradual decrease in radical inhibition over time, which was attributed to lower levels of tocopherol and polyphenol. However, roasted oils showed antifungal action against Botrytis cinerea fungus, while Argan vegetable oils showed no activity against Escherichia coli, Microbacterium resistens, Staphylococcus saprophyticus, and Raoultella ornithinolytica, according to antimicrobial assays.

Multi-omics analysis provides insights into the mechanism underlying fruit color formation in Capsicum

Fruit color is a crucial attribute of fruit quality in peppers (Capsicum spp.). However, few studies have focused on the mechanism of color formation in immature pepper fruits. In this study, the light-yellow color observed in immature CSJ009 fruits compared to CSJ010 could be attributed to decreased chlorophyll and carotenoid pigments. Through integrated analysis of the transcriptome and metabolome of CSJ009 and CSJ010, we identified 23,930 differentially expressed genes (DEGs) and 345 differentially accumulated metabolites (DAMs). Furthermore, integrated analysis revealed a strong correlation between the HCT-like gene and metabolite MWS0178 (chlorogenic acid). Paraffin section assay revealed that the epidermal cells of immature CSJ010 fruits exhibited a more compact arrangement with significantly greater length than those of CSJ009. Quantitative determination of carotenoids showed that lutein emerged as the predominant carotenoid in immature pepper fruits. Additionally, missense mutation of LCYB2 is likely to lead to a decrease in β-carotene content in immature CSJ009 fruits, whereas CCS may directly catalyze the conversion of lycopene to β-carotene in mature fruits. The null mutation in CCS promoted the biosynthesis of β,ϵ-branch carotenoids leading to lutein being the most abundant carotenoid found in orange CSJ010 fruits. These findings provide important insights into the mechanism underlying color formation in pepper fruits and establish a foundation for the further exploration of color-related genes.

Spread of yellow-bill-color alleles favored by selection in the long-tailed finch hybrid system

Carotenoid pigments produce the yellow and red colors of birds and other vertebrates. Despite their importance in social signaling and sexual selection, our understanding of how carotenoid ornamentation evolves in nature remains limited. Here, we examine the long-tailed finch Poephila acuticauda, an Australian songbird with a yellow-billed western subspecies acuticauda and a red-billed eastern subspecies hecki, which hybridize where their ranges overlap. We found that yellow bills can be explained by the loss of C(4)-oxidation, thus preventing yellow dietary carotenoids from being converted to red. Combining linked-read genomic sequencing and reflectance spectrophotometry measurements of bill color collected from wild-sampled finches and laboratory crosses, we identify four loci that together explain 53% of variance in this trait. The two loci of largest effect contain the genes CYP2J19, an essential enzyme for producing red carotenoids, and TTC39B, an enhancer of carotenoid metabolism. A paucity of protein-coding changes and an enrichment of associated upstream variants suggest that the loss of C(4)-oxidation results from cis-regulatory evolution. Evolutionary genealogy reconstruction indicates that the red-billed phenotype is ancestral and that yellow alleles at CYP2J19 and TTC39B first arose and fixed in acuticauda approximately 100 kya. Yellow alleles subsequently introgressed into hecki less than 5 kya. Across all color loci, acuticauda-derived variants show evidence of selective sweeps, implying that yellow bill coloration has been favored by natural selection. Our study illustrates how evolutionary transitions between yellow and red coloration can be achieved by successive selective events acting on regulatory changes at a few interacting genes.

The sugary enhancer1 (se1) Allele Is Associated with Significant Decreases in Carotenoids and Tocotrienols in Yellow (Y1) sugary1 (su1) Sweet Corn

A distinctive phenotype of homozygous sugary enhancer1 (se1) sweet corn (Zea mays) inbreds and hybrids is a light-yellow color in mature kernels. Carotenoid pigments contribute to yellow endosperm color in maize and are of nutritional importance in the human diet along with the related tocochromanols, the E vitamins. Tocochromanols, including both tocopherols and tocotrienols, are antioxidants important in human nutrition and cardiovascular health. Effects of the presence of sugary enhancer1 allele on carotenoid and tocochromanol levels in homozygous su1, Y1 endosperm were evaluated in the Wisconsin Sweet Corn Diversity Panel. Although population structure was present in the panel, the majority of variation in carotenoid levels was explained by genotype at the se1 locus. se1 was associated with significant decreases in the amount of lutein (34%) and zeaxanthin (36%) and decreases of tocotrienols by 12% to 65%. There were no significant differences in β-carotene and tocopherol levels between the two groups. Given that the biosynthesis pathways for carotenoids and tocochromanols are well defined, these differences in carotenoids and tocotrienols between su1Se1 and su1se1 inbreds point to a broader role of se1 alleles in metabolic pathways beyond endosperm starch production.

Portuguese Grapevine Leaves: A Neglected By-Product with High Potential

In Portugal, grapevine leaves are generally treated as agro-industrial waste, despite being rich in bioactive compounds that offer benefits to human health. This study compiles the most relevant and current data on the phytochemical composition and bioactive properties of grape leaves from both red and white varieties cultivated in the country. These by-products are abundant in flavonoid and non-flavonoid phenolic compounds, such as flavonols, derivatives of hydroxycinnamic acids, carotenoid pigments, and chlorophylls, as well as fatty acids, which have scientifically proven antioxidant, antimicrobial, anti-inflammatory, antidiabetic, cardio-, neuro- and hepatoprotective properties, among others. The combination of these beneficial properties, along with the low toxicity of their compounds, makes grapevine leaves a by-product with great potential for use in the food, pharmaceutical, and cosmetic industries. The key challenge is to develop sustainable methods to reintegrate this by-product into the supply chain, in alignment with the sustainability goals of the 2030 Agenda.

Optimization, characterization and biosafety of carotenoids produced from whey using Micrococcus luteus

This study aimed to optimize the production of carotenoid pigments from Micrococcus luteus (ATCC 9341) through the statistical screening of media components and the characterization of antimicrobial, antioxidant, cytogenetic and cytotoxic activities. A BOX-Behnken design was used to assess the effects of whey concentration, inoculum size, pH, temperature, and agitation speed on carotenoid yield. The optimum combination increased production to 2.19 g/L, with a productivity of 0.045 g L-1 h−1 and a productivity yield of 0.644 g/g, as confirmed by an observed carotene production of 2.19 g/L. The final response surface model fitting the data had an R2 of 0.9461. High-performance liquid chromatography (HPLC) analysis identified 12 carotenoid pigment compounds produced by M. luteus. The extracts displayed moderate antimicrobial efficacy against Gram-positive bacteria such as Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 6538), and E. faecalis (ATCC 19433), with inhibition zone diameters (IZD) of 29.0, 14.0, and 37.0 mm, respectively, at 1000 μg/mL. However, its effectiveness against Gram-negative bacteria is limited. In comparison, tetracycline exhibited greater antimicrobial potency. The IC50 value of carotenoids was used to indicate the antioxidant activity. IC50 value from the DPPH assay was 152.80 mg/100mL. An IC50 cytotoxicity value greater than 300 μg/mL was found against normal mouse liver cells, with over 68% cell viability even at 300 μg/mL, indicating low toxicity. Histological structure studies revealed normal myocardial muscle tissue, lung tissue, and kidney tissue sections, whereas liver tissue sections revealed ballooning degeneration of hepatocytes and disorganization of hepatic cords. Cytogenetic parameters revealed that the carotene treatment group had a mitotic index (70%) lower than that of the control but higher than that of the positive control, mitomycin, and did not substantially increase numerical (1.2%) or structural aberrations compared with those of the control, suggesting a lack of genotoxic effects under the experimental conditions. In conclusion, optimized culture conditions enhanced carotenoid yields from M. luteus, and the extracts displayed promising bioactivity as moderate antibiotics against certain gram-positive bacteria and as antioxidants. The high IC50 values demonstrate biosafety. Overall, this bioprocess for enhanced carotenoid production coupled with bioactivity profiling and low cytotoxicity support the application of M. luteus carotenoids.

Conserved carotenoid pigmentation in reproductive organs of Charophyceae.

Sexual reproduction in Charophyceae abounds in complex traits. Their gametangia develop as intricate structures, with oogonia spirally surrounded by envelope cells and richly pigmented antheridia. The red-probably protectant-pigmentation of antheridia is conserved across Charophyceae. Chara tomentosa is, however, unique in exhibiting this pigmentation and also in vegetative tissue. Here, we investigated the two sympatric species, C. tomentosa and Chara baltica, and compared their molecular chassis for pigmentation. Using reversed phase C30 high performance liquid chromatography (RP-C30-HPLC), we uncover that the major pigments are β-carotene, δ-carotene and γ-carotene; using headspace solid-phase microextraction coupled to gas chromatography equipped with a mass spectrometer (HS-SPME-GC-MS), we pinpoint that the unusually large carotenoid pool in C. tomentosa gives rise to diverse volatile apocarotenoids, including abundant 6-methyl-5-hepten-2-one. Based on transcriptome analyses, we uncover signatures of the unique biology of Charophycaee and genes for pigment production, including monocyclized carotenoids. The rich carotenoid pool probably serves as a substrate for diverse carotenoid-derived metabolites, signified not only by (i) the volatile apocarotenoids we detected but (ii) the high expression of a gene coding for a cytochrome P450 enzyme related to land plant proteins involved in the biosynthesis of carotenoid-derived hormones. Overall, our data shed light on a key protection strategy of sexual reproduction in the widespread group of macroalgae. The genetic underpinnings of this are shared across hundreds of millions of years of plant and algal evolution. This article is part of the theme issue 'The evolution of plant metabolism'.

Astaxanthin: a novel antioxidant for polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is a multifactorial endocrine disorder and the most prevalent gynecological condition among women of reproductive age. Current treatment options primarily focus on managing symptoms and fail to fully prevent long-term complications. Astaxanthin (ASX), a red carotenoid pigment, is known for its potent antioxidant, anti-inflammatory, anti-proliferative, and anti-apoptotic properties. This review aims to evaluate the efficacy of astaxanthin supplementation in PCOS management. Our team conducted a comprehensive search of relevant databases up to May 2024, including human clinical trials and animal studies investigating astaxanthin’s effects on PCOS. Of the 45 articles retrieved, 8 met the inclusion criteria (4 animal studies and 4 clinical trials). The majority of the studies demonstrated that astaxanthin has a beneficial impact on ovarian histo morphology and follicular development, with notable reductions in oxidative stress and inflammation among patients with PCOS. Although astaxanthin showed improvement in dyslipidemia, it had no significant effect on weight loss. It is suggested that astaxanthin’s therapeutic potential in PCOS is primarily due to its antioxidant and anti-inflammatory properties rather than its effects on weight. Thus, astaxanthin may be considered a promising therapeutic agent for alleviating PCOS complications; however, further research is warranted due to the limited availability of high-quality clinical trials.

Physicochemical and Color Changes During Fruit Ripening in Pepper Species (C. annuum L., C. baccatum L., and C. chinense Jacq.) Exposed to Salt Stress

This study examines the impact of salt stress on the physicochemical and color characteristics of three pepper species (Capsicum annuum L., Capsicum baccatum L., and Capsicum chinense Jacq.) at different ripening periods. Peppers were exposed to 0 mM, 50 mM, and 100 mM NaCl during the green, breaking, and red ripening periods. The results showed that salt stress significantly influenced moisture content, total ash, pH, titratable acidity, water activity, and color parameters. C. chinense had the highest moisture content and water activity, while C. annuum demonstrated a higher total ash content and pigment density (ASTA value). As fruits ripened, moisture content decreased, and total ash content increased. Salt stress caused reductions in water activity, pH, and titratable acidity, with high salt concentrations leading to increased water loss and a decline in fruit quality. Furthermore, salt stress reduced color parameters and ASTA values, indicating suppressed carotenoid pigment synthesis. The study highlights the importance of developing salt-tolerant pepper varieties, as salt stress negatively impacts the physiological and biochemical quality of peppers. These findings suggest that appropriate agronomic strategies and careful environmental monitoring are essential for sustainable pepper production, particularly in areas with saline soils. The results provide valuable insights into the mechanisms through which salt stress affects pepper fruit quality and suggest avenues for improving crop resilience.

Unbalanced Expression of Structural Genes in Carotenoid Pathway Contributes to the Flower Color Formation of the Osmanthus Cultivar 'Yanzhi Hong'.

Carotenoids are important natural pigments that are responsible for the fruit and flower colors of many plants. The composition and content of carotenoid can greatly influence the color phenotype of plants. However, the regulatory mechanism underling the divergent behaviors of carotenoid accumulation, especially in flower, remains unclear. In this study, a new cultivar Osmanthus fragrans 'Yanzhi Hong' was used to study the regulation of carotenoid pigmentation in flower. Liquid chromatograph-mass spectrometer (LC-MS) analysis showed that β-carotene, phytoene, lycopene, γ-carotene, and lutein were the top five pigments enriched in the petals of 'Yanzhi Hong'. Through transcriptome analysis, we found that the expression of the structural genes in carotenoid pathway was imbalanced: most of the structural genes responsible for lycopene biosynthesis were highly expressed throughout the flower developmental stages, while those for lycopene metabolism kept at a relatively lower level. The downregulation of LYCE, especially at the late developmental stages, suppressed the conversion from lycopene to α-carotene but promoted the accumulation of β-carotene, which had great effect on the carotenoid composition of 'Yanzhi Hong'. Ethylene response factor (ERF), WRKY, basic helix-loop-helix (bHLH), v-myb avian myeloblastosis viral oncogene homolog (MYB), N-Acetylcysteine (NAC), auxin response factor (ARF), and other transcription factors (TFs) have participated in the flower color regulation of 'Yanzhi Hong', which formed co-expression networks with the structural genes and functioned in multiple links of the carotenoid pathway. The results suggested that the cyclization of lycopene is a key link in determining flower color. The modification of the related TFs will break the expression balance between the upstream and downstream genes and greatly influence the carotenoid profile in flowers, which can be further used for creating colorful plant germplasms.

LC.MS-based chemical profiling of Aristotle's lantern and viscera of the sea urchin Echinometra mathaei collected from the Red Sea and evaluation of their antiviral activity

BackgroundEchinometra mathaei (family Echinometridae), is one of the sea urchins widely distributed on the Egyptian coasts in the Red Sea. This organism contains edible and non-edible parts. The present study was carried out to analyze and identify the metabolites present in the non-edible parts (Aristotle's lantern and viscera) using LC/MS. Also, the cytotoxic activity on Vero cell line and antiviral activity against herpes simplex virus type 1 were evaluated using MTT colorimetric assay.ResultsChemical profiling of the crude extracts of Aristotle's lantern and viscera using LC/MS indicated the presence of 51 and 59 compounds, respectively. The main metabolites present in both non-edible parts were phospholipids, amino acids, peptides, fatty acids and glycerol derivatives. However, the characteristic difference was the presence of carotenoid pigments only in viscera. The crude extract of Aristotle's lantern and viscera showed no cytotoxic activity on Vero cell line and significant antiviral activity against herpes simplex virus with an IC50 value equal to 115.48 ± 1.20 and 122.4 ± 0.50 µg/mL, respectively.ConclusionsIn the present study, the crude extracts of the non-edible parts of E. mathaei were analyzed using LC.MS.MS.QTOF and indicated the existence of 110 chemical compounds, with significant antiviral activity against HSV-1 and no cytotoxic activity. The diversity of the identified compounds with two main categories of compounds, phospholipids and peptides, may contribute to the antiviral activity of Aristotle's lantern and viscera. Additionally, this research focused on clarification of nutritive, pharmaceutical and economic values of these parts. As future prospects, further studies are required to isolate the metabolites and assess the detailed mechanism of antiviral activity via in vitro, in vivo and in silico studies.

The effects of trophic mode and medium composition on the biochemical profile and antioxidant capacity of Tetraselmis chuii (CCAP 66/21B)

Microalgal cultivation influences the bioaccumulation of high-value compounds such as omega-3 (ω-3) fatty acids and carotenoid pigments. Therefore, cultivation optimisation is essential to upregulate high-value compound yields. The present study investigated the effects of trophic mode (autotrophy, heterotrophy and mixotrophy) and media composition on the biochemical make-up, pigment signature, fatty acid profile, and antioxidant capacity of the marine chlorophyte, Tetraselmis chuii (CCAP 66/21 B). The 13 conditions significantly affected the biochemical profile of T. chuii (CCAP 66/21 B) with high variation in carbohydrates (78.5–151.7 mg glucose eq g−1dw), lipids (208.3–475.1 mg g−1dw) and soluble proteins (47.3–373.9 mg BSA eq g−1dw). Trophic mode influenced the yields of high-value nutraceutical carotenoids (lutein and β-carotene) with the highest returns observed in photoautotrophic conditions (e.g., 2.51 ± 0.11 mg β-car g−1dw and 1.96 ± 0.14 mg lut g−1dw for K medium). Organic supplementation also induced significant shifts in the proportions of polyunsaturated fatty acids (ω-3 and ω-6 PUFAs), monounsaturated fatty acids (MUFAs) and saturated fatty acids (SFAs). Here, heterotrophy and mixotrophy significantly upregulated MUFA content (33.2 ± 4.0%) and SFA content (31.29 ± 0.9%), respectively. Moreover, mixotrophy significantly enhanced biomass yield (6.3-fold), soluble protein content (3.9-fold) and the antioxidant capacity (5.2-fold) of T. chuii (CCAP 66/21 B) compared to obligate photoautotrophy and heterotrophy. As such, trophic mode is a principal growth parameter that can modulate the content of T. chuii (CCAP 66/21 B) for potential downstream applications such as biofuels, pharmaceuticals, nutracurticals or aquaculture probiotics.

Phytochemical Characterization of Two New Olive Oil Genotypes Growing in Southern Tunisia.

This research can be considered as the first complete survey for the valorization of new olive genotypes cultivated in the South-East of Tunisia as well as their oils. The study aimed to characterize the phytochemical composition of virgin olive oil produced from two olive cultivars, namely Nourgou and Gousalani. The pomological characterization of fruits, the quality criteria and the phytochemical profile were quantified. Additionally, antioxidant activity was evaluated using Ferric reducing antioxidant power (FRAP) and Oxygen radical absorbance capacity (ORAC) tests to also obtain a bioactive characterization of these monovarietal olive oils. The obtained results revealed that the analyzed olive oils samples can be classified into Extra Virgin category (EVOO) according to the regulated physicochemical characteristics. Our findings showed a significant variability in the chemical parameters of the analyzed EVOO likely associated with the genetic potential, mainly for chlorophylls contents (1.37-1.64 mg/kg), in carotenoids pigments (3.97-10.86 mg/kg), in α-tocopherol (175.59-186.87 mg/kg), in sterols (1036.4-1931.4 mg/kg) in oleic acid (65.33-68.73%), in palmitic acid (C16:0) (13.32-17.48%), in linoleic acid (C18:2) (11.06-13.47%). Additionally, the HPLC-MS/MS analysis showed that the two EVOOs analyzed contained appreciable amounts of total polyphenols, ranging from 348.03 up to 516.16 mg/kg, in Nourgou and Gousalani oils, respectively. Regarding the individual phenolic compounds, the EVOO samples were mainly characterized by phenolic alcohols, phenolic acids, secoiridoids, verbascoside, flavonoids and phenolic aldehydes. The prevalent simple phenolics detected were secoiridoids with the dominance of the oleuropein aglycone in Gousalani oil. In addition, findings from in vitro antioxidant assays (FRAP and ORAC) revealed that the two studied oils possessed a powerful antiradical activity and a good reducing power capacity. In conclusion, these new EVOOs exhibited a superior quality compared to other Tunisian varieties, considering their antiradical activity and reducing power capacity.

Extreme halophilic Archaea: Halobacterium salinarum carotenoids characterization and antioxidant properties

Important marine microorganisms are resources of renewable energy that may face global population growth and needs. The application of biomass metabolites, such as carotenoids and their derivatives, may solve some agro-food health problems. Herein, a new halophilic Archaea Halobacterium salinarum producing carotenoid was screened from a Tunisian solar Saltworks (Sfax). The identification of the carotenoid pigments was carried out using HPLC-MS/MS. The predominant pigments produced by this Halobacterium were bacterioruberin and its derivatives and the carotenoids production was found to be of 21.51 mg/mL. Moreover, the data revealed that the carotenoids extract exhibited a high antioxidant activity across four oxidizing assays. The present results suggested that carotenoids extracted from halophilic Archaea are interesting sources of natural antioxidants for future innovative applications in agro-food, cosmetic and health fields.

The effect of the combined application of elicitors to Salvia virgata Jacq. under salinity stress on physiological and antioxidant defense

Salinity stress is one of the most important stress barriers to crop production worldwide. Developing and implementing new strategies against salinity stress is critical for increasing agricultural productivity and supporting sustainable farming. Elicitors such as nanoparticles and Salicylic acid have recently been used potentially for better product yield. Therefore, in our research the Salvia virgata plant was exposed to salinity (NaCl) stress, and zinc oxide nanoparticles (ZnONP), salicylic acid (SA), and the ZnONP + SA combination were applied to plants divided into different groups. While salinity stress decreased the amount of chlorophyll a, chlorophyll b, and carotenoid pigments, SA, ZnONP, and SA + ZnONP elicitors combined with salinity stress enhanced the content of all three pigments. While salt stress raised MDA, H2O2, total phenolic, total flavonoid, soluble sugar and proline content, elicitor applications enhanced proline, soluble sugar, total phenolic and total flavonoid content more. Additionally, the application of NaCl + SA + ZnONP increased proline content by 21.55% and sugar content by 15.73% compared to NaCl application, while decreasing MDA content by 42.28% and H2O2 levels by 42.34%, thereby alleviating the plant's salt stress. It was revealed that DPPH, ABTS, and CUPRAC antioxidant activity sequence used to determine the total antioxidant activity displayed similarities, and it was found as NaCI + ZnONP > NaCI + SA > NaCI + SA + ZnONP > NaCI > Control. Furthermore, all elicitor applications increased CAT, GR, APX, and SOD enzyme activities while reducing oxidative stress in S. virgata plants. When all the data were evaluated, it was confirmed that SA and ZnONP had a synergistic effect and that SA and ZnONP have the potential to support plant development and growth under salinity. SA and ZnONP applications may have the capacity to least the detrimental impacts of salinity stress on plants. However, further research is needed to investigate the effectiveness of SA and ZnONPs in ameliorating salinity or different stress factors in various other plants.

Evolutionary transitions of decapod crustaceans to non-marine, polar, and deep-sea environments: developmental, physiological and biochemical adaptations

Abstract In this brief, non-exhaustive essay, we review major adaptive changes in reproductive and developmental traits of decapod crustaceans, which have passed through evolutionary transitions from ancestral life in coastal marine environments to brackish, limnic, polar, or deep-sea habitats. Two major approaches can be recognised in studies of life-history evolution, focussing on: (1) developmental changes in adaptive physiological or biochemical traits of successive ontogenetic stages, comparing, for instance, osmoregulatory capabilities in larvae, juveniles, and adults (“ontogeny of adaptations” perspective); (2) adaptive changes in the modes of reproduction and development, e.g., enhanced maternal energy investment in egg production, abbreviated, non-feeding larval development (“adaptations in ontogeny”). Using both scientific approaches, Christoph D. Schubart has significantly contributed to our understanding of evolutionary transitions in crustaceans. In our essay, we pay particular attention to the significance of nutritional selection factors in relation to presumably adaptive developmental, physiological, and biochemical traits in different life-history stages. In this context, we highlight the key roles of lipids and carotenoid pigments, in particular of essential polyunsaturated fatty acids (PUFAs) and astaxanthin. While PUFAs and other lipid compounds have received wide scientific attention, we propose that future studies should further analyse also the potential role of astaxanthin and other essential carotenoids.

Studies of TLC-Chromatographic Quantification of Astaxanthin in Dietary Supplements and Its Antioxidant Activity

Astaxanthin is a red carotenoid pigment known for its strong antioxidant and immune-supporting properties, which are higher than other carotenoids. The aim of this study was the qualitative and quantitative evaluation of dietary supplements containing astaxanthin. First, optimal conditions for conducting analyses using the TLC technique with densitometric detection were developed. The mobile phase consisting of methanol: ethyl acetate: 1,4-dioxane (1:3:6 v/v/v) was selected, while the stationary phase consisted of Silica gel 60 F254. Densitometric detection was performed at 460 nm. Next, the validation process of the developed method was carried out according to the guidelines of the International Conference on Harmonization (ICH). The range of linearity tested was 0.0026–0.0100 µg/spot, and the determined LOD and LOQ values were 0.85 and 2.57 ng/μL, respectively. The variation coefficient at the level of 4.75% proves good precision. The percentage of recovery was in the range of 95.25–104.94%. The obtained results confirmed the good accuracy of the method. Subsequently, quantitative analyses of the preparations were carried out. Analysis of dietary supplements showed significant deviations from the declared astaxanthin content. Astaxanthin solutions were stable in alkaline environments and when exposed to light and oxidizing substances; however, the substance degraded in acidic environments. The performed antioxidant capacity tests confirmed the high antioxidant activity of astaxanthin.

Production of nutritionally active compounds from Spirulina platensis under various stress conditions

The free-floating, filamentous cyanobacteria Spirulina platensis is highly valued and in great demand worldwide for its high-value colors and phytonutrients. These compounds find use in health foods, feed, medicines, and diagnostics. The primary objective of this work was to enhance the growth of Spirulina under both oxidative and physiological stress conditions in order to maximize the synthesis of phycocyanin and carotenoid pigments. Cultures were subjected to different concentrations of hydrogen peroxide (H2O2) and sodium chloride for varying temperatures and pH levels. Under lower concentrations of H2O2 (4mM), the maximum carotenoid content was increased, but the phycocyanin content was found to be stimulated at 10mM. Moreover, the synthesis of both pigments was shown to be highest under physiological stress circumstances (40mM and 60mM NaCl concentration) and at an optimal pH of 8-9, helped by a temperature range of 25-30℃. The experimental results demonstrate that both carotenoid and phycocyanin exhibit antioxidant properties even in the presence of oxidative stress. This suggests that the aforementioned circumstances can be applied in future investigations to extract different antioxidants from S. platensis.

Integrating pigment and fatty acid profiles for enhanced estimation of seston community composition

AbstractClimate change, nutrition pollution, and land use alterations influence the primary production of lakes. While light‐microscopy counting remains the standard for estimating phytoplankton community composition, its expense and time‐consuming nature necessitate cost‐effective alternatives for seston analysis. Furthermore, estimating the contribution of seston constituents other than primary producers, or non‐algal particles, is not possible with light‐microscopy counting. Biotracer approach using computational methods and chemotaxonomic biomarkers such as carotenoid pigments and fatty acids have been used as an alternative in seston analysis when species‐level taxonomy is not required. However, a comprehensive testing of how well carotenoid and fatty acids can be used in estimating a wide range of seston phytoplankton communities using different estimation methods is lacking. To assess the accuracy of a suite of state‐of‐the‐art biotracer‐based computational methods, namely CHEMTAX, FASTAR (Fatty Acid Source‐Tracking Algorithm in R), MixSIAR, and QFASA (Quantitative Fatty Acid Signature Analysis), lake water samples were collected in 2016, 2018, 2019, 2020, and 2021 for seston composition analysis in a boreal eutrophic lake with light‐microscopy counting serving as the reference for seston composition. Absolute errors between the biotracer‐based estimates were calculated to evaluate method performance. A small laboratory experiment to assess the reliability of estimating the contribution of non‐algal particles using the computational methods with fatty acids was also conducted. The closest alignment to light‐microscopy counting in terms of absolute error was achieved when both carotenoids and fatty acids were used together in the QFASA method. For CHEMTAX, FASTAR, and MixSIAR, using carotenoids alone produced the closest results. Additionally, the estimation methods accurately assessed the proportion of non‐algal particles in the seston when using fatty acid profiles, a capability not possible with light‐microscopy counting. Our findings demonstrate that the biotracer approach provides a viable and cost‐effective alternative to light‐microscopy counting when group‐level information of phytoplankton community composition suffices. Furthermore, we show that non‐algal particles can be effectively estimated together with phytoplankton when using fatty acids.

Raman spectroscopic analysis of human blood serum of glaucoma patients supplemented with macular pigment carotenoids.

As all major dietary carotenoids are contained in blood, it is a suitable substrate to evaluate their content, in vivo. Following 18-month supplementation of open-angle glaucoma patients with macula-pigment carotenoids (Lutein, Zeaxanthin and Meso-Zeaxanthin) in the European Nutrition in Glaucoma Management trial, Raman spectroscopic analysis of the carotenoid content of pre- and post-supplementation participant blood serum was carried out, to investigate the systemic impact of the supplementation regimen and explore a more direct way of quantifying this impact using routine blood tests. Using a 532 nm laser source for optimal response, a consistent increase in serum carotenoid concentration was observed in the supplemented serum, highest in patients with initial high baseline carotenoid content. A shift in the 1519 cm-1 carotenoid peak also revealed differences in the carotenoid structural profile of the two groups. The findings highlight the potential of Raman spectroscopy toquantify and differentiate carotenoids directly in blood serum.