Zeaxanthin Content Research Articles

A reflection-spectroscopy measured skin carotenoid score strongly correlates with plasma concentrations of all major dietary carotenoid species except for lycopene

Skin carotenoids can be measured non-invasively using spectroscopy methods to provide a biomarker of total dietary carotenoid and carotenoid-rich fruit and vegetable intake. However, the degree to which skin carotenoid biomarkers reflect intakes of specific carotenoids must be determined for specific devices. Previously, findings were mixed regarding the correlation between reflection spectroscopy (RS)-assessed skin carotenoids and individual plasma carotenoid concentrations. The current study expands on prior analyses to examine the cross-sectional associations between adult RS-assessed skin carotenoids and individual carotenoid species intakes and plasma concentrations, controlling for potential covariates. We hypothesized that RS-assessed skin carotenoid scores would strongly correlate with all major plasma carotenoid species other than lycopene. Cross-sectional data from two prior studies (n = 213 and n = 162) examining the validity and sensitivity of RS-assessed skin carotenoids as a biomarker of fruit and vegetable intake were used. Skin carotenoids were assessed using the Veggie Meter ®, which quantifies combined skin carotenoid concentrations. Plasma concentrations of α-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein and zeaxanthin were determined using high-performance liquid chromatography. Self-reported carotenoid intake was estimated from validated food frequency questionnaires. Skin carotenoid scores correlated moderately to strongly with individual plasma carotenoid species (Pearson's r=0.52 – r=0.78) except for lycopene (r=0.04 to r=0.07). Low correlations between skin carotenoid score and lycopene plasma concentrations and intake could be due to differential deposition, preferential oxidation/degradation, and/or device measurement bias. Validating skin carotenoid measurement techniques relative to other concentration biomarkers informs the interpretation of skin carotenoid biomarkers.

Carotenoid and Phenolic Compositions and Antioxidant Activity of 23 Cultivars of Corn Grain and Corn Husk Extract.

As a byproduct of corn processing, corn husk is usually burned or disposed of. To make a better use of corn husk, its bioactive components need to be further explored. In this work, the carotenoids and phenolics of the extracts from the corn grain and corn husk of 15 different yellow corn and 8 different waxy corn were identified and quantified, and their antioxidant activities were assessed. The results showed many considerable variations in carotenoid contents. Four types of carotenoids were observed only in both yellow corn and black waxy corn. The highest lutein and zeaxanthin contents were both observed in yellow corn husks. Lutein dominates in yellow corn, ranging from 494.5 μg/g dw to 2870.8 μg/g dw, which is followed by zeaxanthin, ranging from 63.0 μg/g dw to 360.2 μg/g dw, and finally β-cryptoxanthin and β-carotene. The total content of polyphenols (TPC) and flavonoids (TFC) of the husk from 13 yellow corn cultivars, as well as the TPC of husk from 8 waxy corn cultivars, were all higher than those of their corn grain, with the highest TPC found in waxy corn husk. Additionally, a total of 20 phenolic compounds were identified, and ferulic acid showed the highest content and reached 1101.9 µg/g dw in a waxy corn husk. The average antioxidant activity of a waxy corn husk was 25-65% higher than that of a yellow corn husk, and the highest values were observed in the husk of the waxy corn cultivar Huhong 1. These results suggested that corn husk is a rich source of lutein and phenolics and provided excellent cultivars as a reference for functional food products in agriculture and the food industry.

Impact of pasture feeding cows and seasonality on the concentration of selected fat-soluble compounds in milk and their ability to be used as biomarkers of “Grass-Fed” dairy

This study investigated the impact of proportion of pasture in the cow diet on the concentration of selected fat-soluble compounds in milk including β-carotene, lutein, retinol (vitamin A), α-tocopherol (vitamin E) and zeaxanthin. Bulk tank milk samples (n = 102) were collected weekly (n = 34) across an entire lactation from three herds operating either a high (GRS), medium (PMR) or no pasture allowance (TMR) feeding system. Concentrations of β-carotene and lutein increased significantly with increasing pasture allowance, with a > 2 fold increase of β-carotene in milk, between high and no pasture allowance treatments. GRS feeding system resulted in milks with higher concentrations of retinol, α-tocopherol, and zeaxanthin, compared to both PMR and TMR systems. A biomarker model based on the fat-soluble compounds concentration in milk, demonstrated excellent differentiation of high pasture allowance derived milks from that of medium and no pasture milks, with area under the curve scores of 0.955 and 0.971 respectively. Strong correlations were observed between the concentrations of lutein and zeaxanthin in milk and the milks corresponding yellow colour, while a significant correlation was exhibited between β-carotene and b*-value. Such correlations with milk colour may have a significant impact on the consumer preference of milk and dairy products produced therefrom.

Effect of supplementation with lutein, zeaxanthin, and omega-3 fatty acids on macular pigment and visual function in young adults with long-term use of digital devices: study protocol for a randomized double-blind placebo-controlled study.

Growing evidence emphasizes the importance of xanthophyll carotenoids and omega-3 fatty acids in eye health. However, the beneficial effects of such supplementation have not been thoroughly discussed among adults with high screen exposure. Current trial evidence on lutein bioavailability is contradictory, and the interactions of dietary intervention with host-related factors remain elusive. This study aims to investigate the comparative effectiveness of supplementation with macular xanthophylls and omega-3 fatty acids on macular pigment optical density (MPOD) and visual function, access the bioavailability of free lutein and lutein ester, and explore the complex interplay between genetic variations, intestinal microbiota, and the dietary intervention in Chinese adults with long-term exposure to digital devices. The Lutein, Zeaxanthin, and Omega-3 (LZO) clinical trial is a 24-week multicenter, randomized, double-blind, placebo-controlled trial of 600 participants recruited from research centers, universities, and communities. Individuals are eligible to participate if they are aged over 18 years and use digital devices for over 8 h daily in the last 2 years, and will be randomized to six arms. A total of three visits will be scheduled at baseline, 12 and 24 weeks. The primary outcome is the change in MPOD over the 24-week intervention. The secondary outcomes are changes in visual function (visual acuity, best-corrected visual acuity, contrast and glare sensitivity, critical flicker fusion, reaction time, visuognosis persistence, symptoms and signs of dry eye, retinal thickness, and optical quality), and changes in serum lutein and zeaxanthin concentrations, and erythrocyte membrane omega-3 fatty acids. Genetic variations will be determined using genome-wide genotyping at baseline. 16S rRNA gene sequencing will be utilized to assess microbiome compositional changes before and after intervention. The trial is anticipated to establish early interventions to prevent photochemical ocular damage and delay the onset of vision impairment in young adults with long-term repeated exposure to screen-based electronic devices, and provide valuable insights for the development of precision nutrition strategies for maintaining eye health. www.clinicaltrials.in.th, Identifier, TCTR20220904002.

Carotenoid accumulation in aerial microalga Coelastrella rubescens KGU-H009 in light- and nitrogen-stress conditions

Some natural carotenoids remain unexplored in terms of their function because they occur only in trace amounts, or their stereochemistry is unclear. It is expected that scientists will discover new physiological activities that have a positive impact on human heath by analysis of such carotenoids. The purpose of this study was to analyze the carotenoids synthesized by the novel aerial microalga Coelastrella rubescens KGU–H009, and the dynamics of their accumulation. Cultivation experiments were conducted for 7 days at 25 °C, combining different light conditions with the presence or absence of nitrate ions. Short-term (2-h) cultivation was also performed, and tests were conducted with the addition of the inhibitor of photosynthesis 3-(3,4-dichlorophenyl)-1, 1-dimethylurea (DCMU). Strain KGU-H009 exhibited its highest carotenoid content (34.5 mg g−1) in the presence of nitrogen sources and strong light. Upon nitrogen source depletion, the content of zeaxanthin and β-carotene decreased, while the content of astaxanthin and adonixanthin increased. Strain KGU-H009 exhibited reversible control of the xanthophyll cycle to adapt to changes in light intensity, but the xanthophyll cycle was inhibited by the addition of DCMU. Strain KGU-H009 demonstrated the ability to synthesize carotenoids involved in both light harvesting and photoprotection, suggesting its adaptability to environmental change.

Inclusion of Lutein and Zeaxanthin in Standard or Omega-3 Fatty Acids Enriched Laying Hens Diets: Effects on Performance, Egg Quality Parameters, Fatty Acid Composition and Individual Carotenoids Concentration of Egg Yolk

The effects of lutein (L) and zeaxanthin (Z) inclusion to standard or omega-3 fatty acids enriched laying hens’ diets, on performance, egg quality parameters, fatty acids and individual carotenoids of egg yolk was investigated. The dietary treatments were designed as: standard (S) diet, 50 mg/kg L plus 50 mg/kg Z (S+L/Z (50+50)) or 100 mg/kg lutein plus 100 mg/kg zeaxanthin (S+L/Z (100+100)) added to S diet, Omega-3 fatty acids enriched (OM3) diet, 50 mg/kg lutein plus 50 mg/kg zeaxanthin (OM3+L/Z (50+50) or 100 mg/kg lutein plus 100 mg/kg zeaxanthin (OM3+L/Z (100+100)) added to OM3 diet. Hens with a mean live weight of 1525.88 ± 31.19 g were divided into six treatment groups. During the experimental period, there was not any mortality rate recorded. Dietary inclusion of L/Z (50+50 or 100+100) either in S or OM3 diets did not alter performance parameters. Eggs from hens fed enriched diet (OM3) significantly increased (P<0.05) the albumen index and Haugh unit. The type of dietary fat source (F), equal dose of L/Z or F×L/Z on egg yolk lutein, unknown carotenoids and total carotenoid concentration were found to be significant. However, the F on zeaxanthin concentration was not significant (P>0.05). The yolk color a* value was significantly increased by inclusion of L/Z (50+50 or 100+100) to diets (S or OM3) (P<0.05) and this was correlated with increased (P<0.05) concentration of individual carotenoids. The major changes in egg yolk fatty acid MUFA and PUFA composition occurred when laying hen fed with OM3 diet. Key words: Egg yolk, omega-3, carotenoids, lutein, zeaxanth

Comparison of multi-type chemical compounds in fruits of Lycium and correlations between compounds and traits

To comprehensively reveal and utilize the plant resources of Lycium in China, this study determined and compared the content of monosaccharides, polysaccharides, proteins, carotenoids, organic acids, and phenols in the dried fruits of 8 different Lycium species. Furthermore, the traits including the hundred-fruit weight, shape index, and the ratio of seed to fruit were measured, and the correlations between the content of chemical compounds and fruit traits were assessed. The results showed that L. truncatum, L. barbarum var. auranticarpum, and L. dasystemum var. rubricaulium were the species with high content of monosaccharides. L. barbarum and L. barbarum var. auranticarpum were the species with high content of total polysaccharides, and L. barbarum was the species with high content of carotenoids. L. yunnanense and L. chinense var. potaninii had high content of soluble proteins. L. truncatum, L. dasystemum, and L. barbarum showed high content of organic acids and phenols. L. barbarum and L. barbarum var. auranticarpum demonstrated high fruit weight, while L. yunnanense and L. chinense had high ratios of seed to fruit. The multivariate statistical analysis indicated that polysaccharides, carotenoids, hundred-fruit weight, ratio of seed to fruit, scopolamine, fructose, 5-O-feruloylquinic acid, kaempferol-3-O-rutinoside, scopoletin, cryptochlorogenic acid, and caffeic acid were the main differential compounds in the fruits among different species of Lycium. Moreover, the results of correlation ananysis showed strong correlations between fruit traits and compound content. Specifically, the hundred-fruit weight had positive correlations with the content of total polysaccharides and scopola-mine. The ratio of seed to fruit was negatively correlated with the content of rutin, kaempferol-3-O-rutinoside, fructose, and glucose and positively correlated with the content of succinic acid, soluble proteins, and zeaxanthin. The results implied that chemical compounds presented different distribution patterns in the fruits of 8 Lycium species. This study provides a basis for the comprehensive development and utilization, targeted breeding, and value-added application of Lycium plants.

Response of the phytoplankton size fractions along environmental gradients from an oxygen minimum zone in the central Mexican Pacific

The marine phytoplankton community responds to latitudinal, longitudinal (coast to ocean), and vertical environmental gradients, an important subject in Oxygen minimum zones (OMZ). The phytoplankton structure and the effect of environmental gradients along the central Mexican Pacific, an area within an OMZ, were studied, especially the importance of size fractions and taxonomic groups. A combination of various methods and protocols, such as microscopic analysis, flow cytometer, and pigment analysis, were followed in this study. Oceanographic conditions included thermal gradients along the study area and unreported evidence of a weak upwelling in the southern zone (Acapulco). Vertical distribution of chlorophyll a showed subsurface maxima (SCM, 15-45 m depth) in all stations, and deeper chlorophyll-a maxima (DCM, 85-95 m depth) in more oceanic stations. Chain-forming diatoms dominated in the northern zone stations. Prochlorococcus, Synechococcus, and picoeukaryotes abundances ranged between 0.01 to 21.7 cells×104 mL-1, although most samples showed the highest contribution to biomass (47.95 μg C L-1) by picoeukaryotes. Expected tendencies of Prochlorococcus distribution were observed: highest densities coincided with the DCM and divinyl chlorophyll-a distribution at oceanic stations. Fucoxanthin had the highest concentrations, whereas fucoxanthin and zeaxanthin concentrations were higher at SCM depths. We documented the co-dominance of the pico- and microplankton: picoplankton was important at the DCM, related to oligotrophic and more stratified water column, whereas microplankton prevailed in coastal stations, with mixed water column, high nutrient concentrations, and diatoms as the dominant group. Picoeukaryotes abundances were related to the concentration of prasinoxanthin, which suggests an important mamiellophyte component not previously revealed.

Systems Metabolic Engineering for Efficient Violaxanthin Production in Yeast.

Violaxanthin is a plant-derived orange xanthophyll with remarkable antioxidant activity that has wide applications in various industries, such as food, agriculture, and cosmetics. In addition, it is the key precursor of important substances such as abscisic acid and fucoxanthin. Saccharomyces cerevisiae, as a GRAS (generally regarded as safe) chassis, provides a good platform for producing violaxanthin production with a yield of 7.3 mg/g DCW, which is far away from commercialization. Herein, an integrated strategy involving zeaxanthin epoxidase (ZEP) source screening, cytosol redox state engineering, and nicotinamide adenine dinucleotide phosphate (NADPH) regeneration was implemented to enhance violaxanthin production in S. cerevisiae. 58aa-truncated ZEP from Vitis vinifera exhibited optimal efficiency in an efficient zeaxanthin-producing strain. The titer of violaxanthin gradually increased by 17.9-fold (up to 119.2 mg/L, 15.19 mg/g DCW) via cytosol redox state engineering and NADPH supplementation. Furthermore, balancing redox homeostasis considerably improved the zeaxanthin concentration by 139.3% (up to 143.9 mg/L, 22.06 mg/g DCW). Thus, the highest reported titers of violaxanthin and zeaxanthin in S. cerevisiae were eventually achieved. This study not only builds an efficient platform for violaxanthin biosynthesis but also serves as a useful reference for the microbial production of xanthophylls.

Exogenous salicylic acid promotes carotenoid accumulation and antioxidant capacity in germinated maize kernels by regulating carotenoid biosynthetic pathway

Salicylic acid (SA), as an endogenous plant growth regulator, plays a crucial role in growth and development of plants. This study investigated the influence of varying concentrations of exogenous SA on the physiological and biochemical properties, antioxidant capacity, carotenoid content, and gene expression levels of germinated maize kernels. The results showed that the highest total phenolic and vitamin C contents were found with 0.10 mmol/L of SA, while the highest soluble protein, free amino acid and proline contents were found with 0.50 mmol/L of SA. The content of lutein and zeaxanthin reached the highest under 0.05 mmol/L of SA treatment, which were 18% and 22% higher than that of the control group, respectively. Meanwhile, the expression of seven key genes involved in carotenoid synthesis exhibited different degrees of up-regulation or down-regulation, which may be the reason for promoting carotenoid enrichment in germinated maize kernels. In addition, the antioxidant enzyme activities and antioxidant capacity in germinated maize kernels reached the highest value under the 0.1 mmol/L of SA treatment. Moreover, the correlation analysis results showed the transcription levels of some carotenogenic genes were significantly correlated with carotenoid content or antioxidant capacity. In summary, exogenous SA increased the content of bioactive components, especially carotenoids, and enhanced the antioxidant activity of germinated maize. Therefore, exogenous SA treatment may be used as an efficient germination method to improve the quality of germinated maize.

Comparison of Body Characteristics, Carotenoid Composition, and Nutritional Quality of Chinese Mitten Crab (Eriocheir sinensis) with Different Hepatopancreas Redness.

In this study, we investigated the body characteristics, carotenoid composition, and nutritional quality of Eriocheir sinensis with different hepatopancreas redness (a*). We distributed the crabs into two groups based on the hepatopancreas a* values and compared their body characteristics, chroma, carotenoid composition, and protein, lipid, total sugar, amino acid, and fatty acid content via paired t-test. The results revealed that the relationships between hepatopancreas a* values and crab quality are sex specific. In female crabs, the differences in nutritional characteristics were evident mainly in the hepatopancreases and ovaries. In the redder hepatopancreases, the content of zeaxanthin and β-carotene increased, and the levels of C22:6n3 and C20:5n3 decreased (p < 0.05). In the ovaries, the content of astaxanthin, canthaxanthin, β-carotene, umami, and sweet amino acids were lower in the redder hepatopancreas crabs (p < 0.05). In male crabs, there were positive relationships between hepatopancreas a* and amino acid and fatty acid content. The content of leucine, arginine, and total umami amino acids in muscles and of unsaturated fatty acids and n-6 polyunsaturated fatty acids in hepatopancreases and testicles increased with increasing hepatopancreas a* values (p < 0.05). Therefore, the redder the hepatopancreas, the higher the nutritional quality of male crabs.

High-Pressure Processing of Fruit Smoothies Enriched with Dietary Fiber from Carrot Discards: Effects on the Contents and Bioaccessibilities of Carotenoids and Vitamin E.

The effects of high-pressure processing (HPP) (450 MPa/600 MPa/3 min) on the carotenoid and vitamin E contents of smoothies made from strawberry, orange juice, banana and apple, and the same smoothies enriched with dietary fiber from discarded carrots were compared. The contents and bioaccessibilities of these compounds were also evaluated over the course of 28 days at 4 °C. The application of HPP in the formulations significantly increased the contents of β-cryptoxanthin, α-carotene and β-carotene and retained the contents of lutein, zeaxanthin and vitamin E compared to untreated samples. A decreasing trend in the content of each compound was observed with an increase in storage time. The application of HPP initially led to reductions in the bioaccessibility of individual compounds. However, overall, during storage, there was an increase in bioaccessibility. This suggests that HPP influences cell structure, favoring compound release and micelle formation. HPP is a sustainable method that preserves or enhances carotenoid extractability in ready-to-drink fruit beverages. Furthermore, the incorporation of dietary fiber from carrot processing discards supports circular economy practices and enhances the health potential of the product.

Relationship of Physical Properties and Macronutrient Composition with Carotenoid Profile in Maize Hybrids

Maize hybrids with higher vitreousness contain a higher carotenoid content; however, the relationship between the carotenoid profile and the physical and chemical properties related to vitreousness has not been investigated. The aim of this study was to investigate the relationship among the physical properties (kernel size, hardness, density and bulk density), macronutrient composition (crude protein and fat, starch, amylose, amylopectin and zein) and carotenoid profile (individual, total, α- and β-branch carotenoids and xanthophylls) in the grain of 15 maize hybrids. The tested hybrids displayed high variability for most analyzed traits. Three hybrids were characterized by the predominance of β-branch over α-branch carotenoids, while others showed a more uniform content of both fractions. The kernel hardness was associated with the bulk density, flotation index, kernel sphericity, crude protein and zein content. Hybrids with a higher kernel hardness and associated traits had a higher content of zeaxanthin and other β-branch carotenoids, as well as the total carotenoids. In contrast, lutein and α-branch carotenoids were related to the crude protein and amylopectin content only. The findings of the present study confirmed that kernel hardness is associated with β-branch carotenoids and provided further insight into the relationship between the carotenoid profile and commonly analyzed grain quality properties in maize hybrids. The production of higher quality maize hybrids implies a higher nutritional value of the grain due to the higher carotenoid content.

Drum drying of whole maize flour enhances bioaccessibility of zeaxanthin, α-tocopherol, phytosterols, phenolics and flavonoids

The aim of the present study was to investigate the effect of drum drying of maize flour at slurry concentration of 30%–40% on phytonutrients content and their bioaccessibility. Content of tocopherols (TP), tocotrienol (TT), carotenoids, phytosterols, polyphenols and flavonoids, and antioxidant activity in drum dried maize was decreased. Bioaccessible content of stigmasterol, β-sitosterol and flavonoids was increased in drum dried maize. Bioaccessible content of campesterol and total phenolics was comparable to the bioaccessible content in raw maize. Bioaccessible content of TP, TT, lutein, zeaxanthin and β-carotene decreased in drum dried samples. DPPH + radical scavenging activity of bioaccessible fraction of drum dried maize was increased. The ferric reducing power was stable and total antioxidant activity decreased in bioaccessible fraction of drum dried sample. Percentage bioaccessibility of α-TP, phytosterols, zeaxanthin, phenolics, flavonoids and antioxidant activity was increased. Bioaccessibility of lutein and β-carotene retained, and γ-TP, δ-TP, α-, γ-, δ-TT decreased in drum dried sample. Overall, phytonutrients content was found to be low in drum dried samples, but there was retention of components in bioaccessible fraction which resulted higher percentage bioaccessibility of maize phytonutrients.

Comparative metabolomics reveals complex metabolic shifts associated with nitrogen-induced color development in mature pepper fruit.

Pigments derived from red pepper fruits are widely used in food and cosmetics as natural colorants. Nitrogen (N) is a key nutrient affecting plant growth and metabolism; however, its regulation of color-related metabolites in pepper fruit has not been fully elucidated. This study analyzed the effects of N supply (0, 250, and 400 kg N ha-1) on the growth, fruit skin color, and targeted and non-target secondary metabolites of field-grown pepper fruits at the mature red stage. Overall, 16 carotenoids were detected, of which capsanthin, zeaxanthin, and capsorubin were the dominant ones. N application at 250 kg ha-1 dramatically increased contents of red pigment capsanthin, yellow-orange zeaxanthin and β-carotene, with optimum fruit yield. A total of 290 secondary metabolites were detected and identified. The relative content of most flavonoids and phenolic acids was decreased with increasing N supply. Correlation analysis showed that color parameters were highly correlated with N application rates, carotenoids, flavonoids, phenolic acids, lignans, and coumarins. Collectively, N promoted carotenoid biosynthesis but downregulated phenylpropanoid and flavonoid biosynthesis, which together determined the spectrum of red color expression in pepper fruit. Our results provide a better understanding of the impact of N nutrition on pepper fruit color formation and related physiology, and identification of target metabolites for enhancement of nutritional quality and consumer appeal.

Building food composition tables: extraction methods to measure lutein and zeaxanthin concentrations in select Australian foods

SummaryThe lutein and zeaxanthin (L/Z) in food composition tables has infrequently utilised methods optimised for L/Z and comprehensive data are absent, such as in Australia. These absences limit quality dietary intake research. This study investigated optimisation of extraction methods for lutein and zeaxanthin in five Australian foods analysed by high‐performance liquid chromatography and photodiode array detection. The foods were broccoli, broccolini, baby spinach, baby orange capsicum, and dried goji berry. Twelve variations in extraction methods were investigated, including saponification, sonication, and solvent choice. L/Z concentrations differed by up to more than 125% between variations. Variation nine was best for all foods except zeaxanthin in broccoli where variation five or seven were best. The L/Z concentrations measured differed in Australian and United States data; existing data may therefore not be representative of the current food supply. Development of local Australian food composition data for lutein and zeaxanthin is warranted.

Comparative Responses of Orange-Foot and Common-Foot Haliotis gigantea to Carotenoid-Enriched Diets: Survival, Heat Tolerance, and Bacterial Resistance.

Carotenoids, known to enhance survival, heat tolerance, and bacterial resistance, play an essential role in the nutrition of economically important aquatic animals. This study specifically examined their impact as feed additives on the abalone Haliotis gigantea. We prepared 13 compound feeds with varying levels of astaxanthin, zeaxanthin, and β-carotene, and administered them to both common-footed and orange-footed H. gigantea. The survival rate of H. gigantea was about 70-80%, with no significant differences in survival observed among the various carotenoid-supplemented feeding groups or when compared with the control group, nor between orange-footed and common-footed individuals. In heat attachment duration experiments, orange-foot abalones exhibited longer attachment durations with certain concentrations of astaxanthin and zeaxanthin, whereas common-foot abalones showed extended durations with astaxanthin, zeaxanthin, and β-carotene, indicating that common-foot abalones might benefit more from these carotenoids. Additionally, our results showed similar patterns and levels of Vibrio harveyi AP37 resistance in both orange-footed and common-footed H. gigantea, suggesting a uniform response to carotenoid supplementation in their bacterial defense mechanisms. This study suggests the potential benefits of carotenoid supplementation in H. gigantea and contributes to the theoretical basis for developing high-quality artificial compound feeds.

Leaky mutations in the zeaxanthin epoxidase in Capsicum annuum result in bright-red fruit containing a high amount of zeaxanthin.

Fruit color is one of the most important traits in peppers due to its esthetic value and nutritional benefits and is determined by carotenoid composition, resulting from diverse mutations of carotenoid biosynthetic genes. The EMS204 line, derived from an EMS mutant population, presents bright-red color, compared with the wild type Yuwolcho cultivar. HPLC analysis indicates that EMS204 fruit contains more zeaxanthin and less capsanthin and capsorubin than Yuwolcho. MutMap was used to reveal the color variation of EMS204 using an F3 population derived from a cross of EMS204 and Yuwolcho, and the locus was mapped to a 2.5-Mbp region on chromosome 2. Among the genes in the region, a missense mutation was found in ZEP (zeaxanthin epoxidase) that results in an amino acid sequence alteration (V291 → I). A color complementation experiment with Escherichia coli and ZEP in vitro assay using thylakoid membranes revealed decreased enzymatic activity of EMS204 ZEP. Analysis of endogenous plant hormones revealed a significant reduction in abscisic acid content in EMS204. Germination assays and salinity stress experiments corroborated the lower ABA levels in the seeds. Virus-induced gene silencing showed that ZEP silencing also results in bright-red fruit containing less capsanthin but more zeaxanthin than control. A germplasm survey of red color accessions revealed no similar carotenoid profiles to EMS204. However, a breeding line containing a ZEP mutation showed a very similar carotenoid profile to EMS204. Our results provide a novel breeding strategy to develop red pepper cultivars containing high zeaxanthin contents using ZEP mutations.

Study protocol for a 15-week randomised controlled trial assessing the independent effects of high-cholesterol and high-saturated fat diets on LDL cholesterol

IntroductionPrevious research has associated high dietary cholesterol intake with raised low-density lipoprotein cholesterol (LDL-C) and thus increased risk for cardiovascular disease (CVD). Emerging research suggests that it is saturated fat,...

Characterization of the interindividual variability of lutein and zeaxanthin concentrations in the adipose tissue of healthy male adults and identification of combinations of genetic variants associated with it.

Lutein (L) and zeaxanthin (Z) are involved in visual function and could prevent age-related macular degeneration and chronic diseases and improve cognitive performances. Adipose tissue is the main storage site for these xanthophylls (Xanth). The factors affecting their concentrations in this tissue remain poorly understood but in animal models, genetic variations in apolipoprotein E and β-carotene oxygenase 2 have been associated with adipose tissue L concentration. Therefore, the aims of this study were to better characterize the interindividual variability of adipose tissue Xanth concentration and to identify single nucleotide polymorphisms (SNPs) associated with it. Periumbilical subcutaneous adipose tissue samples were collected on 6 occasions in 42 healthy adult males and L and Z concentrations were measured by HPLC. Participants had their whole genome genotyped and the associations of 3589 SNPs in 49 candidate genes with the concentrations of L and Z were measured. Mean L and Z concentrations were 281 ± 27 and 150 ± 14 nmol g-1 proteins, respectively. There was no significant correlation between plasma and adipose tissue Xanth concentrations, although the correlation for L approached significance (Pearson's r = 0.276, p = 0.077). Following univariate filtering, 109 and 97 SNPs were then entered into a partial least squares regression analysis to identify the combination of SNPs that explained best adipose tissue concentration of L and Z, respectively. A combination of 7 SNPs in ELOVL5, PPARG, ISX and ABCA1, explained 58% of the variability in adipose tissue L concentration while 11 SNPs located in or near PPARG, ABCA1, ELOVL5, CXCL8, IRS1, ISX, MC4R explained 53% of the variance in adipose tissue Z concentration. This suggests that some genetic variations influence the concentrations of these Xanth in adipose tissue and could therefore indirectly influence the health effects of these compounds. Clinical Trial Registry: https://ClinicalTrials.gov registration number NCT02100774.