Extracellular vesicle-mediated secretion of chlorophyll biosynthetic intermediates in the cyanobacterium Leptolyngbya boryana.

Extracellular vesicles (EVs) are derived from the outer membrane (OM) in Gram-negative bacteria and have diverse physiological functions. EV-mediated secretion of monovinyl protochlorophyllide (MV-Pchlide), the chlorophyll a (Chl) biosynthetic intermediate, was previously reported in a mutant lacking dark-operative Pchlide reductase in the cyanobacterium Leptolyngbya boryana. This study showed a detailed characterization of EVs from the wild-type (WT) of L. boryana grown under photoautotrophic and dark heterotrophic conditions, focusing on the accumulation of Chl intermediates. WT L. boryana cells produce two types of EVs, low-density EVs (L-EVs) and high-density EVs (H-EVs), both under light and dark conditions. L-EVs and H-EVs showed distinct morphological features and protein compositions. L-EVs from cells grown under both light and dark conditions commonly contained carotenoids, ketomyxol glycoside, and zeaxanthin, as major pigments. Based on the protein compositions of EVs and other cellular membrane fractions, L-EVs and H-EVs are probably derived from low-density OM and high-density OM interacting with cell walls, respectively. Fluorescence detection of pigments was applied to EVs, and the two Chl intermediates, protoporphyrin IX and protoporphyrin IX monomethyl ester, were commonly detected in both L-EVs from light- and dark-grown cells, whereas L-EVs from dark-grown cells contained additional MV-Pchlide, MV-protopheophorbide, and pheophorbide. The pigment ratios of L-EVs to the total culture medium of the Chl intermediates were much higher than those of carotenoids, suggesting an active transport of the Chl intermediates from the thylakoid membrane to L-EVs. Cyanobacterial EVs may play a novel role in alleviating the accumulation of Chl intermediates in cells. (248 words).

Genetic Engineering and Innovative Cultivation Strategies for Enhancing the Lutein Production in Microalgae.

Carotenoids, with their diverse biological activities and potential pharmaceutical applications, have garnered significant attention as essential nutraceuticals. Microalgae, as natural producers of these bioactive compounds, offer a promising avenue for sustainable and cost-effective carotenoid production. Despite the ability to cultivate microalgae for its high-value carotenoids with health benefits, only astaxanthin and ß-carotene are produced on a commercial scale by Haematococcus pluvialis and Dunaliella salina, respectively. This review explores recent advancements in genetic engineering and cultivation strategies to enhance the production of lutein by microalgae. Techniques such as random mutagenesis, genetic engineering, including CRISPR technology and multi-omics approaches, are discussed in detail for their impact on improving lutein production. Innovative cultivation strategies are compared, highlighting their advantages and challenges. The paper concludes by identifying future research directions, challenges, and proposing strategies for the continued advancement of cost-effective and genetically engineered microalgal carotenoids for pharmaceutical applications.

Production of Fucoxanthin from Microalgae Isochrysis galbana of Djibouti: Optimization, Correlation with Antioxidant Potential, and Bioinformatics Approaches.

Fucoxanthin, a carotenoid with remarkable antioxidant properties, has considerable potential for high-value biotechnological applications in the pharmaceutical, nutraceutical, and cosmeceutical fields. However, conventional extraction methods of this molecule from microalgae are limited in terms of cost-effectiveness. This study focused on optimizing biomass and fucoxanthin production from Isochrysis galbana, isolated from the coast of Tadjoura (Djibouti), by testing various culture media. The antioxidant potential of the cultures was evaluated based on the concentrations of fucoxanthin, carotenoids, and total phenols. Different nutrient formulations were tested to determine the optimal combination for a maximum biomass yield. Using the statistical methodology of principal component analysis, Walne and Guillard F/2 media were identified as the most promising, reaching a maximum fucoxanthin yield of 7.8 mg/g. Multiple regression models showed a strong correlation between antioxidant activity and the concentration of fucoxanthin produced. A thorough study of the optimization of I. galbana growth conditions, using a design of experiments, revealed that air flow rate and CO2 flow rate were the most influential factors on fucoxanthin production, reaching a value of 13.4 mg/g. Finally, to validate the antioxidant potential of fucoxanthin, an in silico analysis based on molecular docking was performed, showing that fucoxanthin interacts with antioxidant proteins (3FS1, 3L2C, and 8BBK). This research not only confirmed the positive results of I. galbana cultivation in terms of antioxidant activity, but also provided essential information for the optimization of fucoxanthin production, opening up promising prospects for industrial applications and future research.

A Comparative Analysis on Impact of Extraction Methods on Carotenoids Composition, Antioxidants, Antidiabetes, and Antiobesity Properties in Seagrass Enhalus acoroides: In Silico and In Vitro Study.

Enhalus acoroides, a tropical seagrass, is known for its significant contribution to marine ecosystems and its potential health benefits due to bioactive compounds. This study aims to compare the carotenoid levels in E. acoroides using green extraction via ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) and to evaluate the biological properties of these extracts against oxidative stress, diabetes, and obesity through in silico and in vitro analyses. E. acoroides samples were collected from Manado City, Indonesia, and subjected to UAE and MAE. The extracts were analyzed using UHPLC-ESI-MS/MS to identify carotenoids, including ß-carotene, lutein, lycopene, ß-cryptoxanthin, and zeaxanthin. In silico analysis was conducted to predict the compounds' bioactivity, toxicity, and drug-likeness using WAY2DRUG PASS and molecular docking with CB-Dock2. The compounds C3, C4, and C7 demonstrated notable interactions, with key metabolic proteins and microRNAs, further validating their potential therapeutic benefits. In vitro assays evaluated antioxidant activities using DPPH and FRAP assays, antidiabetic properties through α-glucosidase and α-amylase inhibition, and antiobesity effects via lipase inhibition and MTT assay with 3T3-L1 cells. Results indicated that both UAE and MAE extracts exhibited significant antioxidant, antidiabetic, and antiobesity activities. MAE extracts showed higher carotenoid content and greater biological activity compared to UAE extracts. These findings suggest that E. acoroides, mainly when extracted using MAE, has promising potential as a source of natural bioactive compounds for developing marine-based antioxidant, antidiabetic, and antiobesity agents. This study supplements existing literature by providing insights into the efficient extraction methods and the therapeutic potential of E. acoroides carotenoids.

Characterization and functions of Myeloblastosis (MYB) transcription factors in cucurbit crops.

Myeloblastosis (MYB) is one of the largest family of transcription factors (TFs) in plants. It plays a key role in plant life activities, such as metabolic regulation, stress resistant, as well as helpful for plant growth and development. In China, cucurbit is an important and nutrients rich vegetable crop, which have high medicinal and socio-economic values. In this review, we discussed the structure and characterization of MYB TFs and how do regulate flower development, fruit maturity, fruit quality, and flavonoid biosynthesis. Furthermore, we highlight the effect and contribution of MYB TFs in the regulation of biotic and abiotic stress resistance. This comprehensive review will provide a new reference for the more effective application of MYB TF in quality control, stress resistance research and molecular breeding of cucurbit crops.

Exogenous application of selenium on sunflower (Helianthus annuus L.) to enhance drought stress tolerance by morpho-physiological and biochemical adaptations.

Drought stress poses a significant obstacle to agricultural productivity, particularly in the case of oilseed crops such as sunflower (Helianthus annuus L.). Selenium (Se) is a fundamental micronutrient that has been recognized for its ability to enhance plant resilience in the face of various environmental stresses. The FH-770 sunflower variety was cultivated in pots subjected to three stress levels (100% FC, 75% FC, and 50% FC) and four Se application rates (0 ppm, 30 ppm, 60 ppm, and 90 ppm). This research aimed to investigate the effect of exogenously applied Se on morpho-physiological and biochemical attributes of sunflower to improve the drought tolerance. Foliar Se application significantly lowered H2O2 (hydrogen peroxide; ROS) (20.89%) accumulation that markedly improved glycine betaine (GB) (74.46%) and total soluble protein (Pro) (68.63%), improved the accumulation of ascorbic acid (AA) (25.51%), total phenolics (TP) (39.34%), flavonoids (Flv) (73.16%), and anthocyanin (Ant) (83.73%), and improved the activity of antioxidant system superoxide dismutase (SOD) (157.63%), peroxidase (POD) (100.20%), and catalase (CAT) (49.87%), which ultimately improved sunflower growth by 36.65% during drought stress. Supplemental Se significantly increased shoot Se content (93.86%) and improved calcium (Ca2+), potassium (K+), and sodium (Na+) ions in roots by 36.16%, 42.68%, and 63.40%, respectively. Selenium supplements at lower concentrations (60 and 90 ppm) promoted the growth, development, and biochemical attributes of sunflowers in controlled and water-deficient circumstances. However, selenium treatment improved photosynthetic efficiency, plant growth, enzymatic activities, osmoregulation, biochemical characteristics, and nutrient balance. The mechanisms and molecular processes through which Se induces these modifications need further investigation to be properly identified.

Comprehensive lipidomic insights of differentially accumulating lipids in large pigmented rice sprout collection and the changes in the starch composition upon germination.

Germination represents a vital bioprocess characterized by numerous biochemical transformations that significantly influence the nutritional characteristics of rice. The mobilization of starch and lipids during germination plays a pivotal role in altering the dietary profile of rice, thus potentially addressing the nutritional requirements of populations heavily reliant on rice as a staple food. To explore this potential, a comprehensive analysis encompassing lipidomics and starch composition was conducted on a diverse collection of pigmented rice sprouts. High-resolution mass spectrometry unveiled substantial shifts in the lipidome of pigmented rice sprouts, showcasing a notable enrichment in carotenoids and unsaturated triglycerides, with potential human health benefits. Notably, purple rice sprouts exhibited heightened levels of alpha- and beta-carotene. Analysis of starch composition revealed slight changes in amylose and amylopectin content; however, a consistent increase in digestible carbohydrates was observed across all rice varieties. Germination also led to a reduction in resistant starch content, with purple rice sprouts demonstrating a pronounced two-fold decrease (p < 0.05). These changes were corroborated by a 1.33% decrease in gelatinization enthalpy and a 0.40% reduction in the melting of the amylose-lipid complex. Furthermore, pasting property analysis indicated a substantial 42% decrease in the complexation index post-germination. We posit that the insights garnered from this study hold significant promise for the development of novel products enriched with health-promoting lipids and characterized by unique flour properties.

Oral Administration of Carotenoid-Rich Dunaliella salina Powder Inhibits Colon Carcinogenesis via Modulation of Wnt/ß-catenin Signaling Cascades in a Rat Model.

The present study aims to investigate the oral therapeutic and molecular role of carotenoid-rich Dunaliella salina powder (DSP) against 1,2-dimethylhydrazine (DMH)-triggered colon carcinogenesis. In this study, thirty six male Wistar rats were categorized into six distinct groups (G1-G6): G1 group with no intervention, G2 group received only DSP (1000 mg/kg), G3 group received only DMH carcinogen (20 mg/kg), and G4-G6 group received both DMH and DSP at various phases (pre-initiation, post-initiation and entire phases) for 32 weeks. Body weight, tumor incidence, tumor volume, histopathological examination, antioxidants, and detoxification enzymes activities were analyzed in the experimental rats. In addition, the protein expression profile of components involved in the Wnt/ß-catenin signaling pathway was determined by western blot analysis. Matrix metalloproteinases (MMP-7 and MMP-9), proliferation marker (PCNA), and pro-apoptotic (Bcl-2 and Bax) proteins were analyzed using immunohistochemistry. Colorimetric assay was used to determine the levels of anti-inflammatory (iNOS and COX-2) and apoptotic proteins (Caspase-3 and Caspase-9). Results showed that concomitant administration of DSP with DMH significantly reduced tumor progression and prevented colon carcinogenesis in rats. However, treatment with DSP before or after DMH exposure did not significantly prevent colon carcinogenesis. DMH and DSP treatment group showed increased activities of antioxidant enzymes with significant reduction in the oxidative stress. Additionally, the detoxification enzymes and colonic histopathology of those rats were restored to that of control rats. The administration of DSP to rats exposed to DMH exhibited antitumor effects via inhibition of the Wnt/ß-catenin signaling pathway with induced apoptosis through the Bcl-2/Bax/caspases signaling cascades. Moreover, the same group also showed significant anti-inflammatory activity via regulating iNOS and COX-2 biomarkers. Our findings revealed molecular chemopreventive activity of carotenoid-rich DSP through regulating Wnt/beta-catenin and intrinsic apoptotic pathways. Thus, DSP is propound to function as a potent antioxidant, anti-proliferative, and anti-inflammatory therapeutic agent against colon carcinogenesis.

A novel mutation in non-constitutive lycopene beta cyclase (CstLcyB2a) from Crocus sativus modulates carotenoid/apocarotenoid content, biomass and stress tolerance in plants.

MAIN CONCLUSION: Mutation at A126 in lycopene-ß-cyclase of Crocus (CstLcyB2a) sterically hinders its binding of δ-carotene without affecting lycopene binding, thereby diverting metabolic flux towards ß-carotene and apocarotenoid biosynthesis. Crocus sativus, commonly known as saffron, has emerged as an important crop for research because of its ability to synthesize unique apocarotenoids such as crocin, picrocrocin and safranal. Metabolic engineering of the carotenoid pathway can prove a beneficial strategy for enhancing the quality of saffron and making it resilient to changing climatic conditions. Here, we demonstrate that introducing a novel mutation at A126 in stigma-specific lycopene-ß-cyclase of Crocus (CstLcyB2a) sterically hinders its binding of δ-carotene, but does not affect lycopene binding, thereby diverting metabolic flux towards ß-carotene formation. Thus, A126L-CstLcyB2a expression in lycopene-accumulating bacterial strains resulted in enhanced production of ß-carotene. Transient expression of A126L-CstLcyB2a in C. sativus stigmas enhanced biosynthesis of crocin. Its stable expression in Nicotiana tabacum enhanced ß-branch carotenoids and phyto-hormones such as abscisic acid (ABA) and gibberellic acids (GA's). N. tabacum transgenic lines showed better growth performance and photosynthetic parameters including maximum quantum efficiency (Fv/Fm) and light-saturated capacity of linear electron transport. Exogenous application of hormones and their inhibitors demonstrated that a higher ratio of GA4/ABA has positive effects on biomass of wild-type and transgenic plants. Thus, these findings provide a platform for the development of new-generation crops with improved productivity, quality and stress tolerance.

Assessing the carotenoid profiles and allelic diversity of yellow maize inbred lines adapted to mid-altitude subhumid maize agroecology in Ethiopia.

Biofortification of provitamin A in maize is an attractive and sustainable remedy to the problem of vitamin A deficiency in developing countries. The utilization of molecular markers represents a promising avenue to facilitate the development of provitamin A (PVA)-enriched maize varieties. We screened 752 diverse tropical yellow/orange maize lines using kompetitive allele-specific PCR (KASP) makers to validate the use of KASP markers in PVA maize breeding. To this end, a total of 161 yellow/orange inbred lines, selected from among the 752 lines, were evaluated for their endosperm PVA and other carotenoid compounds levels in two separate trials composed of 63 and 98 inbred lines in 2020 and 2021, respectively. Significant differences (p < 0.001) were observed among the yellow maize inbred lines studied for all carotenoid profiles. An inbred line TZMI1017, introduced by the International Institute of Tropical Agriculture (IITA) showed the highest level of PVA (12.99 µg/g) and ß-carotene (12.08 µg/g). The molecular screening showed 43 yellow maize inbred lines carrying at least three of the favorable alleles of the KASP markers. TZMI1017 inbred line also carried the favorable alleles of almost all markers. In addition, nine locally developed inbred lines had medium to high PVA concentrations varying from 5.11 µg/g to 10.76 µg/g and harbored the favorable alleles of all the KASP PVA markers. Association analysis between molecular markers and PVA content variation in the yellow/orange maize inbred lines did not reveal a significant, predictable correlation. Further investigation is warranted to elucidate the underlying genetic architecture of the PVA content in this germplasm. However, we recommend strategic utilization of the maize-inbred lines with higher PVA content to enhance the PVA profile of the breeding program's germplasm.

Vitamin A carotenoids, but not retinoids, mediate the impact of a healthy diet on gut microbial diversity.

BACKGROUND: Vitamin A is essential for physiological processes like vision and immunity. Vitamin A's effect on gut microbiome composition, which affects absorption and metabolism of other vitamins, is still unknown. Here we examined the relationship between gut metagenome composition and six vitamin A-related metabolites (two retinoid: -retinol, 4 oxoretinoic acid (oxoRA) and four carotenoid metabolites, including beta-cryptoxanthin and three carotene diols). METHODS: We included 1053 individuals from the TwinsUK cohort with vitamin A-related metabolites measured in serum and faeces, diet history, and gut microbiome composition assessed by shotgun metagenome sequencing. Results were replicated in 327 women from the ZOE PREDICT-1 study. RESULTS: Five vitamin A-related serum metabolites were positively correlated with microbiome alpha diversity (r = 0.15 to r = 0.20, p < 4 × 10-6). Carotenoid compounds were positively correlated with the short-chain fatty-acid-producing bacteria Faecalibacterium prausnitzii and Coprococcus eutactus. Retinol was not associated with any microbial species. We found that gut microbiome composition could predict circulating levels of carotenoids and oxoretinoic acid with AUCs ranging from 0.66 to 0.74 using random forest models, but not retinol (AUC = 0.52). The healthy eating index (HEI) was strongly associated with gut microbiome diversity and with all carotenoid compounds, but not retinoids. We investigated the mediating role of carotenoid compounds on the effect of a healthy diet (HEI) on gut microbiome diversity, finding that carotenoids significantly mediated between 18 and 25% of the effect of HEI on gut microbiome alpha diversity. CONCLUSIONS: Our results show strong links between circulating carotene compounds and gut microbiome composition and potential links to a healthy diet pattern.

Boosting pro-vitamin A content and bioaccessibility in leaves by combining engineered biosynthesis and storage pathways with high-light treatments.

Biofortification of green leafy vegetables with pro-vitamin A carotenoids, such as ß-carotene, has remained challenging to date. Here, we combined two strategies to achieve this goal. One of them involves producing ß-carotene in the cytosol of leaf cells to avoid the negative impacts on photosynthesis derived from changing the balance of carotenoids and chlorophylls in chloroplasts. The second approach involves the conversion of chloroplasts into non-photosynthetic, carotenoid-overaccumulating chromoplasts in leaves agroinfiltrated or infected with constructs encoding the bacterial phytoene synthase crtB, leaving other non-engineered leaves of the plant to sustain normal growth. A combination of these two strategies, referred to as strategy C (for cytosolic production) and strategy P (for plastid conversion mediated by crtB), resulted in a 5-fold increase in the amount of ß-carotene in Nicotiana benthamiana leaves. Following several attempts to further improve ß-carotene leaf contents by metabolic engineering, hormone treatments and genetic screenings, it was found that promoting the proliferation of plastoglobules with increased light-intensity treatments not only improved ß-carotene accumulation but it also resulted in a much higher bioaccessibility. The combination of strategies C and P together with a more intense light treatment increased the levels of accessible ß-carotene 30-fold compared to controls. We further demonstrated that stimulating plastoglobule proliferation with strategy P, but also with a higher-light treatment alone, also improved ß-carotene contents and bioaccessibility in edible lettuce (Lactuca sativa) leaves.

Chitosan-coated manganese ferrite nanoparticles enhanced Rhodotorula toruloides carotenoid production.

The present study aims to analyze the interaction between Rhodotorula toruloides and magnetic nanoparticles and evaluate their effect on carotenoid production. The manganese ferrite nanoparticles were synthesized without chitosan (MnFe2O4) and chitosan coating (MnFe2O4-CS) by the co-precipitation method assisted by hydrothermal treatment. XRD (X-ray diffraction), Magnetometry, Dynamic Light Scattering (DLS) and FTIR (Fourier-Transform Infrared Spectroscopy), are used to characterize the magnetic nanoparticles. The crystallite size of MnFe2O4 was 16 nm for MnFe2O4 and 20 nm for MnFe2O4-CS. The magnetic saturation of MnFe2O4-CS was lower (39.6 ± 0.6 emu/g) than the same MnFe2O4 nanoparticles (42.7 ± 0.3 emu/g), which was attributed to the chitosan fraction presence. The MnFe2O4-CS FTIR spectra revealed the presence of the characteristic chitosan bands. DLS demonstrated that the average hydrodynamic diameters were 344 nm for MnFe2O4 and 167 nm for MnFe2O4-CS. A kinetic study of cell immobilization performed with their precipitation with a magnet demonstrated that interaction between magnetic nanoparticles and R. toruloides was characterized by an equilibrium time of 2 h. The adsorption isotherm models (Langmuir and Freundlich) were fitted to the experimental values. The trypan blue assay was used for cell viability assessment. The carotenoid production increased to 256.2 ± 6.1 µg/g dry mass at 2.0 mg/mL MnFe2O4-CS. The use of MnFe2O4-CS to stimulate carotenoid yeast production and the magnetic separation of biomass are promising nanobiotechnological alternatives. Magnetic cell immobilization is a perspective technique for obtaining cell metabolites.

Clinical management of eye diseases: carotenoids and their nanoformulations as choice of therapeutics.

Eye diseases, such as age-related macular degeneration (AMD) and diabetic retinopathy (DR), impose a substantial health cost on a worldwide scale. Carotenoids have emerged as intriguing candidates for pharmacological treatment of various disorders. Their therapeutic effectiveness, however, is hindered by poor solubility and vulnerability to degradation. Nanocarriers, such as nanoparticles, liposomes, and micelles, provide a transformational way to overcome these limits. This review explores the pharmacological potential of carotenoids, namely lutein, zeaxanthin, and astaxanthin, to treat several ocular disorders. The main emphasis is on their anti-inflammatory and antioxidant actions, which help to counteract inflammation and oxidative stress, crucial factors in the development of AMD and DR. The review evaluates the significant benefits of nano-formulated carotenoids, such as improved bioavailability, higher cellular absorption, precise administration to particular ocular tissues, and greater biostability, which make them superior to conventional carotenoids. Some clinical studies on the beneficial properties of carotenoids in eye diseases are discussed. Furthermore, safety and regulatory concerns are also taken into account. Ultimately, carotenoids, especially when created in their nano form, have significant potential for safeguarding eyesight and enhancing the overall well-being of several individuals afflicted with vision-endangering eye diseases.

Investigating the inhibitory effects of carotenoids-fortified Helix aspersa slime on oxidative stress, collagenase and tyrosinase enzyme activities.

BACKGROUND: The investigations of snail slime and its possible biological activities have been performed recently. AIM: This study aimed to evaluate the properties of Helix aspersa snail slime (HAS), and carotenoids-fortified slime (HASC). METHODS: Snails were fed with carrots for 10 days. Slime was collected and extracted using water. Saponins identification, antioxidant, collagenase, and tyrosinase enzyme inhibition activities, carotenoids, total phenols, and flavonoids content, were determined. UHPLC-MS/MS analysis was performed for phytochemical characterization. RESULTS: Saponins were detected in the HAS extract only. However, HASC was shown to contain a higher carotenoid content than HAS (29.51 ± 0.4 vs. 18.11 ± 0.2 µg/g). similarly, total phenolic and flavonoid content were higher for the the HASC extract compared to the HAS (182.3 ± 5.2 vs. 150.28 ± 3.3 mg/g equivalent to gallic acid), and (77.62 ± 1.2 vs. 14.19 ± 0.9 mg/g equivalent to quercetin). As expected, the HASC extract exhibited higher antioxidant activity compared to the HAS, using DPPH and the ABTS assays (IC50 = 7.75 ± 0.14 vs. 20.1 ± 0.4 µg/mL), and (IC50 = 7.6 ± 0.26 vs. 19.57 ± 1.4 µg/mL). UHPLC-MS/MS analysis revealed the presence of several phytocomponents of which, hexadecanoic acid and ascorbic acid, were observed in the HASC extract. Furthermore, HASC extract exhibited superior inhibitory activity compared to HAS against collagenase and tyrosinase enzymes (IC50 = 8.4 ± 1.19 vs. 15.3 ± 1.12 µg/mL) and (IC50 = 30.1 ± 0.91 vs. 35 ± 1.3 µg/mL). CONCLUSION: These findings highlight the potential of HASC as a valuable ingredient in various pharmaceutical applications, due to their content of various phenolic, antioxidants, carotenoids, hexadecanoic, and ascorbic acids. The latter is well known for its great cosmeceutical applications used for slowing the process of skin aging.

Impact of thermal processing on polyphenols, carotenoids, glucosinolates, and ascorbic acid in fruit and vegetables and their cardiovascular benefits.

Bioactive compounds in fruit and vegetables have a positive impact on human health by reducing oxidative stress, inflammation, and the risk of chronic diseases such as cancer, cardiovascular (CV) diseases, and metabolic disorders. However, some fruit and vegetables must be heated before consumption and thermal processes can modify the amount of nutraceuticals, that is, polyphenols, carotenoids, glucosinolates, and ascorbic acid, that can increase or decrease in relation to different factors such as type of processing, temperature, and time but also the plant part (e.g., flower, leaf, tuber, and root) utilized as food. Another important aspect is related to the bioaccessibility and bioavailability of nutraceuticals. Indeed, the key stage of nutraceutical bioefficiency is oral bioavailability, which involves the release of nutraceuticals from fruit and vegetables in gastrointestinal fluids, the solubilization of nutraceuticals and their interaction with other components of gastrointestinal fluids, the absorption of nutraceuticals by the epithelial layer, and the chemical and biochemical transformations into epithelial cells. Several studies have shown that thermal processing can enhance the absorption of nutraceuticals from fruit and vegetable. Once absorbed, they reach the blood vessels and promote multiple biological effects (e.g., antioxidant, anti-inflammatory, antihypertensive, vasoprotective, and cardioprotective). In this review, we described the impact of different thermal processes (such as boiling, steaming and superheated steaming, blanching, and microwaving) on the retention/degradation of bioactive compounds and their health-promoting effects after the intake. We then summarized the impact of heating on the absorption of nutraceuticals and the biological effects promoted by natural compounds in the CV system to provide a comprehensive overview of the potential impact of thermal processing on the CV benefits of fruit and vegetables.

Preparation of two amphiphilic dendritic small molecule gelators based on poly (aryl ether) modified silica-based chromatographic stationary phases and molecular shape recognition for shape-restricted isomers.

Geometric isomers tend to have similar polarities and differ only in molecular shape. Vigorously developing new stationary phases to meet the requirements for the separation of isomers that have similar physicochemical properties is still an urgent topic in separation science. Poly (arylene ether)-based dendrimers are known for their multifunctional branched peripheral structures and high self-assembly properties. In this paper, two amphiphilic dendritic organic small molecule gelling agents based on poly (aryl ether), PAE-ANT and PAE-PA, were prepared and conjugated to the silica surface. SiO2@PAE-ANT and SiO2@PAE-PA were used as HPLC stationary phases for the separation of non-polar shape-restricted isomers. Both stationary phases have very high molecular shape selectivity for isomers such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), tocopherols and carotenoids. Separation of cis-trans geometric isomers such as diethylstilbestrol and polar compounds such as monosubstituted benzenes and anilines can also be achieved. These two columns offer more flexible selectivity and higher separation performance than commercial C18 and phenyl columns. There is a difference in molecular shape selectivity between the two stationary phases for the same analyte test probes. SiO2@PAE-ANT showed slightly better linear selectivity for non-polar shape-restricted isomers compared to SiO2@PAE-PA with Janus-type PAE-PA bonding phase. This separation behavior may be attributed to the ordered spatial structure formed by the gel factor on the surface of the stationary phase and the combined effect of multiple weak interaction centers (hydrophobic, hydrophilic, hydrogen bonding and π-π interactions). It was also possible to separate nucleoside and nucleobase strongly polar compounds well in the HILIC mode, suggesting that hydrophilic groups in PAE-ANT and PAE-PA are involved in the interactions, reflecting their amphiphilic nature. The results show that the ordered gelation of dendritic organic small molecule gelators on the SiO2 surface, along with multiple carbonyl-π, π-π and other interactions, play a crucial role in the separating shape-restricted isomers. The integrated and ordered functional groups serve as the primary driving force behind the exceptionally high molecular shape selectivity of SiO2@PAE-ANT and SiO2@PAE-PA phases. Alterations in the structure of dendritic organic small molecule gelators can impact both molecular orientation and recognition ability, while changes in the type of functional groups influences the separation mechanism of shape-restricted isomers.

Increase in polyunsaturated fatty acids and carotenoid accumulation in the microalga Golenkinia brevispicula (Chlorophyceae) by manipulating spectral irradiance and salinity.

Microalgal biotechnology offers a promising platform for the sustainable production of diverse renewable bioactive compounds. The key distinction from other microbial bioprocesses lies in the critical role that light plays in cultures, as it serves as a source of environmental information to control metabolic processes. Therefore, we can use these criteria to design a bioprocess that aims to stimulate the accumulation of target molecules by controlling light exposure. We study the effect on biochemical and photobiological responses of Golenkinia brevispicula FAUBA-3 to the exposition of different spectral irradiances (specifically, high-fluence PAR of narrow yellow spectrum complemented with low intensity of monochromatic radiations of red, blue, and UV-A) under prestress and salinity stress conditions. High light (HL) intensity coupled to salinity stress affected the photosynthetic activity and photoprotection mechanisms as shown by maximal quantum yield (Fv/Fm) and non-photochemical quenching (NPQmax) reduction, respectively. HL treatments combined with the proper dose of UV-A radiation under salinity stress induced the highest carotenoid content (2.75 mg g dry weight [DW]- 1) composed mainly of lutein and ß-carotene, and the highest lipid accumulation (35.3% DW) with the highest polyunsaturated fatty acid content (alpha-linolenic acid (C18:3) and linoleic acid (C18:2)). Our study can guide the strategies for commercial indoor production of G. brevispicula for high-value metabolites.

Multiple Mechanisms of Haematococcus pluvialis-Derived Carotenoids to Inhibit Glycidyl Ester Formation in Rice Oil and a Chemical Model at High Temperatures.

The common presence of glycidyl esters (GEs) in refined vegetable oils has been a concern for food safety. The present study aimed to investigate the inhibitory effects of three carotenoids derived from Haematococcus pluvialis microalga on GE formation in both rice oil and a chemical model during heating. The addition of astaxanthin (AS), lutein (LU), and ß-carotene (CA) at 0.6 mg/g in rice oil can reduce GE formation by 65.0%, 57.1%, and 57.5%, respectively, which are significantly higher than those achieved by common antioxidants such as l-ascorbyl palmitate (39.0%), α-tocopherol (18.5%), tert-butyl hydroquinone (42.7%), and quercetin (26.2%). UPLC-Q-TOF-MS/MS analysis showed that two new compounds, that is, propylene glycol monoester and diester of palmitic acid, were formed in the CA-added chemical model, which provided direct experimental evidence for the inhibition of antioxidants including AS, LU, and CA against GE formation not only by indirect antioxidative action but also by direct radical reactions to competitively prevent the formation of cyclic acyloxonium intermediates. Furthermore, it was interestingly found that only AS could react with the GEs. The adduct of AS with GEs, astaxanthin-3-O-propanetriol esters, was preliminarily identified using Q-TOF-MS/MS in the heated AS-GE model, suggesting that reacting with GEs might represent another distinct mechanism of AS to eliminate GEs.

Integrating multiple statistical indices to measure the stability of photosynthetic pigment content and composition in Brassica juncea (L.) Czern germplasm under varying environmental conditions.

Understanding the stability of photosynthetic pigments is crucial for developing crop cultivars with high productivity and resilience to the environmental stresses. This study leveraged GGE biplot, WAASB, and MTSI indices to assess the stability of content and composition of photosynthetic pigments in leaves and siliques of 286 Brassica juncea (L.) Czern. genotypes across three environments. The GGE biplot analysis identified NRCQR-9901 as the best genotype in terms of chlorophyll 'a' under conditions of high irradiance and long days (E1). For chlorophyll 'b' and total chlorophyll, NC-533728 performed the best. AJ-2 and NPJ-208 had the maximum total carotenoids levels in leaves. RLC-2 was characterized by maximum values for chlorophyll a, chlorophyll b, and total chlorophyll in the siliques. The low irradiance, short days, and moderate to high temperatures (E2) seemed perfect for the synthesis of photosynthetic pigments. NPJ-182 shows the maximum concentrations of chlorophyll 'a', total chlorophyll, and total carotenoids in leaves. Conversely, IC-597869, RE-389, and IC-597894 exhibited the highest concentrations of chlorophyll 'b' under an environment characterized by low light intensity, shorter daylights, and low temperatures (E3) during flowering and siliqua formation stages. The combined analysis found NPJ-182, NC-533728, CN-105233, RLC-2, CN-101846, JA-96, PBR-357, JM-3, and DTM-34 as top performers with high stability. Comparative transcriptome analysis with two stable and high-performing genotypes (PBR-357 and DTM-34) and two average performers revealed upregulation of critical photosynthesis-related genes (ELIP1, CAB3.1, ELIP1.5, and LHCB5) in top performers. This study identified promising trait donors for use in breeding programs aimed at improving the mustard crop's photosynthetic efficiency, productivity, and stability.