Differences In Carotenoid Content Research Articles

Physicochemical and sensory evaluation of the quality of crude palm oil (Elaeis guineensis) produced artisanally and industrially in Brazil

Palm oil is primarily used in the crude form in northeastern Brazil's cuisine. Most of its production is carried out by small manufacturers, who use the profits from sales as a subsidy to supplement their family income. Evaluating the physicochemical and sensory quality of palm oil is essential to help producers develop higher-quality artisanal products. This study aimed to analyze samples of crude palm oil produced and sold in the city of Taperoá (BA) and other industrialized brands sold in Salvador (BA). Seven palm oil samples underwent physicochemical analysis (acidity, carotenoid content, instrumental color, iodine value, peroxide value, Kreis reaction, saponification value) and sensory analysis (acceptance and ranking tests). Our findings revealed significant variation in the evaluated parameters, with most samples showing inadequate results for the regulatory parameters of acidity and iodine values, as well as unsatisfactory results for carotenoids and the Kreis reaction across all samples. Variations in color analysis were likely associated with differences in carotenoid content among the samples. The acceptance tests showed that most samples scored above average for all evaluated characteristics, except for the industrial sample from Taperoá (sample 06), which showed the lowest averages for color (4.5), odor (5.2), viscosity (3.2), and overall impression (4.3). In the ranking test, sample 02 from artisanal production (Taperoá-BA) was the most preferred in all categories, while sample 06 from industrial production (Nazaré-BA) was the least preferred in all categories. These results indicate opportunities for improving both traditional and industrial crude palm oil production methods, which could lead to an increase in income for the population that depends on this product.

Carotenoid content in Ulva lactuca cultivated under aquaculture conditions and collected from intertidal beds in southeastern Brazil: biotechnological implications for biomass use and storage

Ulva lactuca is an edible green macroalga (Chlorophyta) that can be produced in cultivation systems; it is a natural source of high-value molecules. Ulva lactuca produces metabolites including carotenoids, which are pigments with antioxidant properties that are in high demand in the health and nutraceutical industries and improve the nutritional quality of U. lactuca biomass. We studied the carotenoid and chlorophyll content in U. lactuca thalli collected in 3 different environments in the state of Rio de Janeiro, Brazil: the intertidal beds of the urban beaches of Arpoador and Boa Viagem and a continental integrated multi-trophic aquaculture (IMTA) facility. Carotenoid conservation was evaluated during 1 week, 2 weeks, and 4 weeks of storage. We compared the molecules in fresh U. lactuca collected during the dry season (July 2018) and rainy season (February 2019). The content of carotenoids, such as β-carotene + zeaxanthin, lutein + antheraxanthin, violaxanthin, neoxanthin, and their derivatives (aurochrome and auroxanthin), were analyzed in 100% acetone extracts by ultraviolet visible (UV/vis) spectrophotometry and monitored by thin layer chromatography (TLC) and proton nuclear magnetic resonance (1H-NMR). The extracts of dried U. lactuca produced in the IMTA facility presented higher pigment yields than the dried biomass collected from intertidal beds. Over 4 weeks of storage, carotenoids were well conserved in U. lactuca produced in the IMTA facility, in contrast to what was observed in U. lactuca collected from the intertidal beds, which showed carotenoid losses. In addition, we observed differences in carotenoid content between the dry and rainy seasons in U. lactuca collected from Boa Viagem Beach. However, the U. lactuca collected from Arpoador Beach or produced by the IMTA facility only exhibited significant differences in chlorophyll content. We conclude that U. lactuca produced by the IMTA facility constitutes a potential source of pigments such as β-carotene, lutein, and violaxanthin.

Effect of hydrogen sulfide (H2S) on the growth and development of tobacco seedlings in absence of stress

BackgroundHydrogen sulfide (H2S) is a novel signaling molecule involved in the growth and development of plants and their response to stress. However, the involvement of H2S in promoting the growth and development of tobacco plants is still unclear.ResultsIn this study, we explored the effect of pre-soaking or irrigating the roots of tobacco plants with 0.0, 2.0, 4.0, 6.0, and 8.0 mM of sodium hydrosulfide (NaHS) on endogenous H2S production, antioxidant enzymatic and cysteine desulfhydrase activities, seed germination, agronomic traits, photosynthetic pigments contents, and root vigor. The results revealed that exogenous NaHS treatment could significantly promote endogenous H2S production by inducing gene expression of D/L-CD and the activities of D/L-CD enzymes. Additionally, a significant increase in the agronomic traits and the contents of photosynthetic pigments, and no significant difference in carotenoid content among tobacco plants treated with 0.0 to 8.0 mM of NaHS was observed. Additionally, a significant increase in the germination speed, dry weight, and vigor of tobacco seeds, whereas no significant effect on the percentage of seed germination was observed on NaHS treatment. Furthermore, NaHS treatment could significantly increase the activity of superoxide dismutase (SOD) and peroxidase (POD) enzymes, which reduces damage due to oxidative stress by maintaining reactive oxygen species homeostasis.ConclusionsThese results would aid in enhancing our understanding of the involvement of H2S, a novel signaling molecule to promote the growth and development of tobacco plants.

Genetic and physiological responses to light quality in a deep ocean ecotype of Ostreococcus, an ecologically important photosynthetic picoeukaryote.

Phytoplankton are exposed to dramatic variations in light quality when cells are carried by upwelling or downwelling currents or encounter sediment. We investigated the potential impact of light quality changes in Ostreococcus, a key marine photosynthetic picoeukaryote, by analysing changes in its transcriptome, pigment content, and photophysiology after acclimation to monochromatic red, green, or blue light. The clade B species RCC809, isolated from the deep euphotic zone of the tropical Atlantic Ocean, responded to blue light by accelerating cell division at the expense of storage reserves and by increasing the relative level of blue-light-absorbing pigments. It responded to red and green light by increasing its potential for photoprotection. In contrast, the clade A species OTTH0595, which originated from a shallow water environment, showed no difference in photosynthetic properties and minor differences in carotenoid contents between light qualities. This was associated with the loss of candidate light-quality responsive promoter motifs identified in RCC809 genes. These results demonstrate that light quality can have a major influence on the physiology of eukaryotic phytoplankton and suggest that different light quality environments can drive selection for diverse patterns of responsiveness and environmental niche partitioning.

Subcutaneous and Orbital Adipose Tissues: Intrinsic Differences in Carotenoid Contents and Lipidomic Compositions.

The color difference in human subcutaneous fat (SF) and orbital fat (OF) is apparent, but the reasons have been rarely elaborated. We speculate that differences in carotenoid and lipid contents may account for the discrepancy in color. In this study, the intrinsic differences in SF and OF were analyzed using ultrahigh-performance liquid chromatography coupled with Q-Exactive liquid chromatography mass spectrometry/mass spectrometry (UPLC-QE Plus LC-MS/MS). Lipid profiling was performed in an independent batch. The morphology between orbital septum and SF differed statistically in the size of adipocytes and the distribution area of adipocytes. We compared carotenoid contents between two groups (seven samples) and found that lutein was more abundant in SF than that in OF with a p-value of 0.0409, suggesting that lutein could be mainly responsible for the yellow color of adipose tissue. Lipidomic results proved that SF and OF were well differentiated. Totally, 402 lipid features were detected, with 349 features in the positive ion mode and 53 features in the negative ion mode. Features (99.9%) in the positive ion mode and features (98.7%) in the negative ion mode well described various separation patterns in principal component analysis. Thirty-two features selected by variable importance in projection might account for the diversity of compounds in SF and OF. In conclusion, SF and OF differed from each other in carotenoids and lipidome. It is helpful to study the metabolism process of lipid droplets in adipocytes.

Carotenoid Profiling of Yellow-Flesh Peach Fruit.

In this study, the carotenoid profiles and content in 132 cultivars of yellow-flesh peach having different fruit developmental periods (short, middle, and long), fruit surface indumenta (glabrous and pubescent skin), and flesh colors (yellow, golden, and orange) were investigated. We simultaneously analyzed and compared the levels of five carotenoids (lutein, zeaxanthin, β-cryptoxanthin, α-carotene, and β-carotene) through high-performance liquid chromatography. Large differences in carotenoid content among germplasms were observed, with coefficients of variation ranging from 21.24% to 67.78%. The carotenoid content, from high to low, was as follows: β-carotene > zeaxanthin > α-carotene > β-cryptoxanthin > lutein. We screened several varieties with high carotenoid content, including zeaxanthin in ‘Ruiguang2’, β-cryptoxanthin in ‘NJN76’ and ‘TX4F244C’, and β-carotene and total carotenoids in ‘Jintong7’, ‘77-26-7’, and ‘77-20-5’. A longer fruit developmental period was associated with greater β-carotene accumulation but lowered the zeaxanthin and β-cryptoxanthin accumulation. The zeaxanthin, β-carotene, and total carotenoid concentrations significantly increased as the flesh color deepened, but the lutein and α-carotene levels remained similar among the three flesh colors. The classification index of the indumenta significantly affected the β-carotene and total carotenoid content (p < 0.05) and was higher in pubescent than glabrous skin.

Optimization of total carotenoids extraction from pequi pulp (Caryocar brasiliense Camb.) using a mixture planning method/ Otimização da extração de carotenoides totais da polpa de pequi (Caryocar brasiliense Camb.) usando método de planejamento de misturas

The pequi is a native fruit of the Brazilian Savanna and the consumption of its carotenoid-rich pulp has been associated with several health benefits. However, there are considerable differences in carotenoid content reported for this fruit, mainly due to the diversity of extraction methods used in the recovery of these compounds from pequi pulp. The objective of this study was to evaluate the efficiency of different organic solvents and mixtures in the extraction of total carotenoids from pequi pulp. For the carotenoids extraction, pure solvents and the mixtures of acetone, ethyl alcohol and petroleum ether were used. The mixture planning was used to determine the proportions of the solvents in each treatment. To our knowledge, this is the first study to identify that the most efficient treatment for total carotenoid extraction from pequi pulp is pure petroleum ether solvent (234.40 μg/g). In contrast, ethyl alcohol was the solvent that extracted the lowest concentration of total carotenoids (124.03 μg/g). Pure acetone, one of the most used solvents in the extraction of carotenoids from pequi, showed intermediate efficiency (166.07 μg/g). Thus, pure petroleum ether is the solvent recommended for total carotenoid extraction, mainly in the samples rich in carotenoid and lipids, such as pequi pulp.

2A-linked bi-, tri-, and quad-cistrons for the stepwise biosynthesis of β-carotene, zeaxanthin, and ketocarotenoids in rice endosperm

Foot-and-mouth disease virus (FMDV) 2A constructs have been successfully used for the production of “Golden Rice”, a β-carotene producing rice strain. However, to allay public fears and opposition to plants carrying a mammalian pathogenic viral sequence, 2A-like synthetic sequences from Thosea asigna virus and Infectious myonecrosis virus were used to coordinate the coexpression of carotenoid biosynthetic genes. Here, up to four carotenogenic genes encoding PSY, CRTI, BCH and BKT were concatenated and produced β-carotene, zeaxanthin, and ketocarotenoids (astaxanthin and adonixanthin) in transgenic rice seeds displaying color variation due to the difference in carotenoid content and composition.

Rhodotorula mucilaginosa C2.5t1 Modulates Carotenoid Content and CAR Genes Transcript Levels to Counteract the Pro-Oxidant Effect of Hydrogen Peroxide.

In order to contribute to the elucidation of the biological role of carotenoids, the cellular response to hydrogen peroxide was analyzed in the red yeast R. mucilaginosa. For that, the wild strain C2.5t1, that produces β-carotene, torulene, and torularhodin, and the albino mutant 200A6 that is incapable of producing detectable amounts of these carotenoids, were grown in the presence of increasing concentrations of hydrogen peroxide. In spite of the difference in carotenoid content, the two strains presented comparable resistance to the pro-oxidant that showed a minimum inhibitory concentration of 6 mM. When subject to 1 h treatment with 16 mM hydrogen peroxide the two strains increased catalase but not superoxide activity, suggesting that catalase plays a major role in cell protection in both the wild strain and the albino mutant. Moreover, C2.5t1 reduced its carotenoid content by about 40% upon hydrogen peroxide treatment. This reduction in carotenoids was in agreement with a significant decrease of the transcript levels of genes involved in carotenoid biosynthesis. Since an excess of β-carotene may enhance reactive oxygen species toxicity, these results suggest that C2.5t1 modulates carotenoid content to counteract the pro-oxidant effect of hydrogen peroxide.

Investigation of chromoplast ultrastructure and tissue-specific accumulation of carotenoids in citrus flesh

Citrus flesh color due to the accumulation of carotenoids in chromoplasts is one of the most important traits for breeding. However, the relationship between carotenoids and chromoplast ultrastructure in citrus is largely unclear. Thus, in this study fourteen representative citrus cultivars including those with yellow, orange, and red flesh were comparatively analyzed by light microscopy, exhibiting three types of chromoplasts (i.e. globular, fusiform and crystalloid). Significant differences in carotenoid content and cell wall thickness were found in sub-divided tissues of three grapefruits by high performance liquid chromatography and transmission electron microscopy. Based on our findings, it could be inferred that the accumulation of lycopene was closely related to the formation of crystalline chromoplasts. In the meantime, 'Flame' grapefruit with high content of carotenoids and cells with thin cell wall would have greater bio-accessibility, which indicated that 'Flame' grapefruit was superior to 'Star Ruby' grapefruit in the processing of citrus pulp juice. In conclusion, bio-accessibility influenced by chromoplasts and cell wall should be taken into consideration in citrus nutritional breeding, and differences in carotenoid accumulation and chromoplast morphology with tissue-specific characteristics would provide a new insight for further research.

Changes in phytochemical composition, bioactivity and in vitro digestibility of guayusa leaves (Ilex guayusa Loes.) in different ripening stages.

Guayusa (Ilex guayusa Loes.) leaves, native of the Ecuadorian Amazon, are popularly used for preparing teas. This study aimed to assess the influence of leaf age on the phenolic compounds and carotenoids and the bioactivity and digestibility (in vitro) of aqueous and hydroalcoholic leaf extracts. In total, 14 phenolic compounds were identified and quantified. Chlorogenic acid and quercetin-3-O-hexose were the main representatives of the hydroxycinnamic acids and flavonols respectively. Seven carotenoids were quantified, lutein being the main compound. Ripening affected phenolic content significantly, but there was no significant difference in carotenoid content. Antioxidant capacity, measured by the DPPH• method, was also significantly affected by leaf age. The measurement of in vitro digestibility showed a decrease in phenolic content (59%) as well as antioxidant capacity, measured by the ABTS•+ method, in comparison with initial conditions of the guayusa infusion. Antibacterial and anti-inflammatory activities were assayed with young leaves owing to their higher phenolic contents. Guayusa did not show any antibacterial activity against Escherichia coli ATCC 25922 or Staphylococcus aureus ATCC 25923. Finally, the hydroalcoholic and aqueous extracts exhibited high in vitro anti-inflammatory activity (>65%). Young guayusa leaves have potential applications as a functional ingredient in food and pharmaceutical industries. © 2017 Society of Chemical Industry.

Carotenoid gene expression explains the difference of carotenoid accumulation in carrot root tissues.

Main conclusion Variations in gene expression can partially explain the difference of carotenoid accumulation in secondary phloem and xylem of fleshy carrot roots. The carrot root is well divided into two different tissues separated by vascular cambium: the secondary phloem and xylem. The equilibrium between these two tissues represents an important issue for carrot quality, but the knowledge about the respective carotenoid accumulation is sparse. The aim of this work was (i) to investigate if variation in carotenoid biosynthesis gene expression could explain differences in carotenoid content in phloem and xylem tissues and (ii) to investigate if this regulation is differentially modulated in the respective tissues by water-restricted growing conditions. In this work, five carrot genotypes contrasting by their root color were studied in control and water-restricted conditions. Carotenoid content and the relative expression of 13 genes along the carotenoid biosynthesis pathway were measured in the respective tissues. Results showed that in orange genotypes and the purple one, carotenoid content was higher in phloem compared to xylem. For the red one, no differences were observed. Moreover, in control condition, variations in gene expression explained the different carotenoid accumulations in both tissues, while in water-restricted condition, no clear association between gene expression pattern and variations in carotenoid content could be detected except in orange-rooted genotypes. This work shows that the structural aspect of carrot root is more important for carotenoid accumulation in relation with gene expression levels than the consequences of expression changes upon water restriction.

Effects of long-term olive mill wastewater spreading on the physiological and biochemical responses of adult Chemlali olive trees (Olea europaea L.)

Olive mill wastewater (OMW), a by-product from the olive oil extraction process, is annually produced in huge amounts in olive-growing areas and represents a significant environmental problem in Mediterranean areas. Whereas its high organic load and polyphenols concentrations are associated with troublesome environmental effects, its rich mineral and organic matter contents represent valuable nutrients. This study aimed to investigate adult ‘Chemlali’ olive trees subjected to OMW application at three doses (50, 100, and 200m3ha−1year−1) after eight successive years in an olive field. The main focus of the study was on gas exchange characteristics, photosynthetic pigments, soluble sugars, total phenolic compounds, antioxidant activity, leaf mineral nutrient and yield of the trees. The findings showed significant raises of net photosynthesis (Pn) and stomatal conductance (Gs) in OMW treated olive trees by 50 and 100m3ha−1. The lowest Pn and Gs rates were recorded in treatment with the highest OMW dose (200m3ha−1). In addition, olive trees amended with 200m3ha−1 exhibited a significant decrease of both chlorophyll (a+b) and carotenoid contents, while olive plants which received 50 and 100m3ha−1 of OMW showed higher photosynthetic pigments contents compared to the control olive trees. However, there was no significant difference in carotenoid content. Soluble sugars, total phenol contents and antioxidant activity increment were noticed in leaf plants amended with a 200m3ha−1 dose. The OMW spreading rates at 50 and 100m3ha−1 significantly increased the mineral contents of leaves (N, P, K, Ca and Mg). Nevertheless, the highest OMW application was associated with a significant reduction of olive leaf nutrient concentrations. Olive yield showed a continuous improvement of up to 100m3ha−1year−1 spread rate. The present study confirms that olive trees responses were dependent on OMW dose applied. Consequently, key physiological parameters of adult olive trees seemed to benefit from spreading OMW at moderate doses (50 and 100m3ha−1year−1) while the application of a higher dose (200m3ha−1year−1) seemed to disrupt them.

Ambient UV-B radiation inhibits the growth and physiology of Brassica napus L. on the Qinghai-Tibetan plateau

Increased amounts of ultraviolet-B (UV-B) radiation reaching the Earth's surface through stratospheric ozone depletion are expected to have a negative effect on plant responses. However, the reliability of extrapolating indoor experiments to infer plant responses under field conditions has been questioned. Here, we report the growth and physiological responses of Brassica napus L. crops grown on the Qinghai-Tibetan plateau to different levels of ambient UV-B radiation (100%, 70%, and 25%). Here, we aimed to obtain a realistic evaluation of the effect of high UV-B radiation on B. napus L. crops in this region. We used three experimental groups: control (ambient UV-B radiation), T1 (25% exclusion of solar UV-B), and T2 (70% exclusion of solar UV-B). Compared to the control, exclusion of solar UV-B radiation enhanced specific leaf weight (SLW) and caused plant height increased with a significant increase in biomass. Ambient UV-B radiation caused the UV-B absorbing compounds of the leaves to increase, while chlorophyll a, b, and (a+b) content decreased. No significant differences in carotenoid content were detected among the three groups. Compared to the control, exclusion of solar UV-B radiation reduced antioxidant enzyme activity. Moreover, the results showed that exposure to UV-B radiation caused B. napus to (i) increase UV-B absorbing compounds to reduce the transmittance of UV photons through the leaf tissue, (ii) enhance antioxidant enzyme activity to scavenge reactive oxygen species (ROS), and (iii) increase carotenoids to prevent oxidative damage. However, the bleaching of chlorophyll a and damage to the photosynthetic apparatus by solar UV-B radiation caused a reduction in the photosynthetic rate.

Differences in carotenoid content of normal elderly and Alzheimerˈs brains

Alzheimerˈs Disease (AD) is a severe neurodegenerative disease that inflicts &gt;4,500,000 US elderly. Antioxidants, such as carotenoids, have been implicated in the prevention of degenerative diseases and recent data correlates blood and macular carotenoid levels with cognition.PurposeTo measure and compare the major carotenoids in normal elderly and AD human brain.MethodsSamples of normal and AD brain tissue from frontal lobe cortex and occipital cortex were examined. Sections were dissected into gray and white matter, extracted with organic solvents, and analyzed by HPLC.ResultsAt least 16 carotenoids, 3 tocopherols, and retinol were present in human brain. Xanthophylls accounted for &gt;70% of carotenoids in the brain. Mean concentrations of carotenoids ranged from 3.5–15.3 pmol/g. Combining all brains, lutein (LUT, P&lt;0.001) and zeaxanthin (ZX, P&lt;0.02) were higher in gray vs white matter. ZX and LUT were lower in AD brain (P&lt;0.002, P&lt;0.04, respectively). Healthy brain had 2× more ZX and 30% more LUT than AD brain. Retinol and α‐tocopherol were lower in AD brain, (p&lt;0.002, P&lt;0.006).ConclusionsAD status is negatively correlated with levels of ZX, LUT, vitamins A and E in specific brain tissue.

Detection of a Cis eQTL Controlling BMCO1 Gene Expression Leads to the Identification of a QTG for Chicken Breast Meat Color

Classical quantitative trait loci (QTL) analysis and gene expression QTL (eQTL) were combined to identify the causal gene (or QTG) underlying a highly significant QTL controlling the variation of breast meat color in a F2 cross between divergent high-growth (HG) and low-growth (LG) chicken lines. Within this meat quality QTL, BCMO1 (Accession number GenBank: AJ271386), encoding the β-carotene 15, 15′-monooxygenase, a key enzyme in the conversion of β-carotene into colorless retinal, was a good functional candidate. Analysis of the abundance of BCMO1 mRNA in breast muscle of the HG x LG F2 population allowed for the identification of a strong cis eQTL. Moreover, reevaluation of the color QTL taking BCMO1 mRNA levels as a covariate indicated that BCMO1 mRNA levels entirely explained the variations in meat color. Two fully-linked single nucleotide polymorphisms (SNP) located within the proximal promoter of BCMO1 gene were identified. Haplotype substitution resulted in a marked difference in BCMO1 promoter activity in vitro. The association study in the F2 population revealed a three-fold difference in BCMO1 expression leading to a difference of 1 standard deviation in yellow color between the homozygous birds at this haplotype. This difference in meat yellow color was fully consistent with the difference in carotenoid content (i.e. lutein and zeaxanthin) evidenced between the two alternative haplotypes. A significant association between the haplotype, the level of BCMO1 expression and the yellow color of the meat was also recovered in an unrelated commercial broiler population. The mutation could be of economic importance for poultry production by making possible a gene-assisted selection for color, a determining aspect of meat quality. Moreover, this natural genetic diversity constitutes a new model for the study of β-carotene metabolism which may act upon diverse biological processes as precursor of the vitamin A.

Induced point mutations in the phytoene synthase 1 gene cause differences in carotenoid content during tomato fruit ripening

In tomato, carotenoids are important with regard to major breeding traits such as fruit colour and human health. The enzyme phytoene synthase (PSY1) directs metabolic flux towards carotenoid synthesis. Through TILLING (Targeting Induced Local Lesions IN Genomes), we have identified two point mutations in the Psy1 gene. The first mutation is a knockout allele (W180*) and the second mutation leads to an amino acid substitution (P192L). Plants carrying the Psy1 knockout allele show fruit with a yellow flesh colour similar to the r, r mutant, with no further change in colour during ripening. In the line with P192L substitution, fruit remain yellow until 3 days post-breaker and eventually turn red. Metabolite profiling verified the absence of carotenoids in the W180* line and thereby confirms that PSY1 is the only enzyme introducing substrate into the carotenoid pathway in ripening fruit. More subtle effects on carotenoid accumulation were observed in the P192L line with a delay in lycopene and β-carotene accumulation clearly linked to a very slow synthesis of phytoene. The observation of lutein degradation with ripening in both lines showed that lutein and its precursors are still synthesised in ripening fruit. Gene expression analysis of key genes involved in carotenoid biosynthesis revealed that expression levels of genes in the pathway are not feedback-regulated by low levels or absence of carotenoid compounds. Furthermore, protein secondary structure modelling indicated that the P192L mutation affects PSY1 activity through misfolding, leading to the low phytoene accumulation.

Variations in Bran Carotenoid Levels within and between Rice Subgroups

Rice (Oryza sativa L.) is a major grain in the human diet and carotenoids are valuable antioxidants. However, little is known about varietal differences in the carotenoid contents of the rice bran. The objective of this study is to determine the relative differences in bran carotenoid levels among all the five subgroups of rice. Measurements were made by a recently described, rapid non-destructive fluorescence quenching method. Confirmation by high performance liquid chromatography (HPLC) after solvent extraction of the bran indicated that the major carotenoid was lutein. Our data showed that carotenoid levels were stable over 10 years of storage. Tropical japonica rice, the most consumed subgroup in the United States, tended to have the lowest levels of carotenoids in the bran while temperate japonicas had the highest. These differences in carotenoid content may open up new opportunities for identifying or breeding rice varieties with higher nutritional value.

Interspecific differences in carotenoid content and sensitivity to UVB radiation in three acanthocephalan parasites exploiting a common intermediate host

Few endoparasite species are pigmented. Acanthocephalans are an exception however, with several species being characterised by yellow to orange colouration both at the immature (cystacanth) and adult stages. However, the functional and adaptive significance of carotenoid-based colourations in acanthocephalans remains unclear. One possibility is that the carotenoid content of acanthocephalan cystacanths acts as a protective device against ultra-violet radiation (UVR) passing through the translucent cuticle of their crustacean hosts. Indeed, acanthocephalans often bring about behavioural changes in their aquatic intermediate hosts that can increase their exposure to light. Carotenoid composition and damage due to ultra-violet – B (UVB) radiation were investigated in three acanthocephalan parasite species that induce contrasting behavioural alterations in their common intermediate host, the crustacean amphipod Gammarus pulex. The fish acanthocephalans Pomphorhynchus laevis and Pomphorhynchus tereticollis both induce a positive phototaxis in gammarids, such that infected hosts spend more time out of shelters, while remaining benthic. The bird acanthocephalan Polymorphus minutus, on the other hand, induces a negative geotaxis, such that infected hosts typically swim close to the water surface, becoming more exposed to UV radiation. We show that differences in cystacanth colouration between acanthocephalan species directly reflect important differences in carotenoid content. The two fish parasites exhibit a contrasting pattern, with P. tereticollis harbouring a large diversity of carotenoid pigments, whereas P. laevis is characterised by a lower carotenoid content consisting mainly of lutein and astaxanthin. The highest carotenoid content is found in the bright orange P.minutus, with a predominance of esterified forms of astaxanthin. Exposure to UVB radiation revealed a higher susceptibility in P. laevis larvae compared with P. tereticollis and P. minutus, in terms of sublethality (decreased evagination rate) and of damage to DNA (increased cyclobutane pyrimidine dimers production). Although we found important and correlated interspecific differences in carotenoid composition and tolerance to high UVB radiation, our results do not fully support the hypothesis of adaptive carotenoid-based colourations in relation to UV protection. An alternative scenario for the evolution of carotenoid accumulation in acanthocephalan parasites is discussed.

Carotenoid Biosynthetic Pathway in the Citrus Genus: Number of Copies and Phylogenetic Diversity of Seven Genes

The first objective of this paper was to analyze the potential role of allelic variability of carotenoid biosynthetic genes in the interspecific diversity in carotenoid composition of Citrus juices. The second objective was to determine the number of copies for each of these genes. Seven carotenoid biosynthetic genes were analyzed using restriction fragment length polymorphism (RFLP) and simple sequence repeats (SSR) markers. RFLP analyses were performed with the genomic DNA obtained from 25 Citrus genotypes using several restriction enzymes. cDNA fragments of Psy, Pds, Zds, Lcy-b, Lcy-e, Hy-b, and Zep genes labeled with [alpha-(32)P]dCTP were used as probes. For SSR analyses, two primer pairs amplifying two SSR sequences identified from expressed sequence tags (ESTs) of Lcy-b and Hy-b genes were designed. The number of copies of the seven genes ranged from one for Lcy-b to three for Zds. The genetic diversity revealed by RFLP and SSR profiles was in agreement with the genetic diversity obtained from neutral molecular markers. Genetic interpretation of RFLP and SSR profiles of four genes (Psy1, Pds1, Lcy-b, and Lcy-e1) enabled us to make inferences on the phylogenetic origin of alleles for the major commercial citrus species. Moreover, the results of our analyses suggest that the allelic diversity observed at the locus of both of lycopene cyclase genes, Lcy-b and Lcy-e1, is associated with interspecific diversity in carotenoid accumulation in Citrus. The interspecific differences in carotenoid contents previously reported to be associated with other key steps catalyzed by PSY, HY-b, and ZEP were not linked to specific alleles at the corresponding loci.