Nutritional and clinical relevance of lutein in human health

Carotenoids: From Plants to Food and Feed Industries

In this review, carotenoids from plants are described, and their natural existence is addressed. Carotenoids are 40-carbon isoprenoid molecules that produce the red, yellow, and orange pigmentation found in nature. Various plants, microalgae, bacteria, and fungi are natural sources of carotenoids and are presented in detail. The chemistry of carotenoids and their classification is also described along with the effect of carotenoids on human health which is explained with focus on lutein-zeaxanthin, astaxanthin, canthaxanthin, capsanthin, and lycopene. Clinical studies suggest that carotenoid consumption is associated with lower risk of cardiovascular disease, cancer, and eye disease. Finally, another issue discussed is the role of carotenoids in animals and their feed with focus on birds, fish and crustaceans, livestock, and poultry.

Preparative Recovery of Carotenoids from Microalgal Biomass

Carotenoids are widespread substances with important physiological roles, and some of them, such as lutein, astaxanthin, or vaucherioxanthin, are high-value products that can be used as high-quality food color and antioxidants, and some have an alleged role in the prevention of disorders such as AMD. Carotenoid extracts are currently obtained from plant sources, but microalgae have been demonstrated to be a competitive source likely to become an alternative. The extraction of carotenoids from microalgae possesses specific problems that arise from the different structure and composition of the source biomass. Here is presented a method for the recovery of carotenoid extracts from microalgal biomass in the kilogram scale.

Carotenoids Production: A Healthy and Profitable Industry

Carotenoids relevance as natural pigments is mainly due to their uses as colorants, feed supplements, nutraceuticals and for medical, cosmetic, and biotechnological purposes. Since they have putative health beneficial effects, the demand and market of carotenoids are growing significantly. There is a diversity of natural and synthetic carotenoids, but only a few of them are commercially produced, including carotenes (β-carotene and lycopene) and xanthophylls (astaxanthin, canthaxanthin, lutein, zeaxanthin, and capsanthin). Some biotechnological processes for carotenoids production were established some years ago, but new strains and technologies are being developed nowadays for carotenoids widely in demand. This chapter shows a revision of the main carotenoids from a commercial point of view.

Lutein and zeaxanthin isomers modulates lipid metabolism and the inflammatory state of retina in obesity-induced high-fat diet rodent model

Background

Several studies associated high-fat intakes with a high incidence of age-related macular degeneration (AMD). Lutein and Zeaxanthin isomers (L/Zi) may counteract reactive oxygen species produced by oxidative stress. The present study was conducted to determine the possible effects of L/Zi administration on lipid profile, protein genes associated with oxidative stress and inflammation pathways in the obesity induced by a high-fat diet (HFD) in rodents.

Methods

Twenty-eight male Wistar rats were allocated into four groups as follows: (i) Control, (ii) Control + L/Zi, (iii) High Fat Diet (HFD), and (iv) HFD+ L/Z. L/Zi was administrated for 8 weeks at a daily dose of 100 mg/kg BW.

Results

L/Zi administration significantly reduced insulin and free fatty acid (FFA) levels (P < 0.001) and ameliorated the oxidative damage by reducing malondialdehyde (MDA) concentration and increasing antioxidant enzymes activities of retina induced by HFD. In addition, supplementation decreased the levels of vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB) and intercellular adhesion molecule-1 (ICAM) (P < 0.001, respectively) and improved nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) gene proteins in retinal tissues (P < 0.001).

Conclusion

Rats fed with HFD exhibited increased oxidative stress and upregulation of inflammatory indicators. However, L/Zi supplementation modulates genes involved oxidative stress and inflammation including NF-κB and Nrf2 signaling pathways in the retina which may contribute to ameliorating retinal damage induced by HFD.

The Pharmacological Effects of Lutein and Zeaxanthin on Visual Disorders and Cognition Diseases

Lutein (L) and zeaxanthin (Z) are dietary carotenoids derived from dark green leafy vegetables, orange and yellow fruits that form the macular pigment of the human eyes. It was hypothesized that they protect against visual disorders and cognition diseases, such as age-related macular degeneration (AMD), age-related cataract (ARC), cognition diseases, ischemic/hypoxia induced retinopathy, light damage of the retina, retinitis pigmentosa, retinal detachment, uveitis and diabetic retinopathy. The mechanism by which they are involved in the prevention of eye diseases may be due their physical blue light filtration properties and local antioxidant activity. In addition to their protective roles against light-induced oxidative damage, there are increasing evidences that L and Z may also improve normal ocular function by enhancing contrast sensitivity and by reducing glare disability. Surveys about L and Z supplementation have indicated that moderate intakes of L and Z are associated with decreased AMD risk and less visual impairment. Furthermore, this review discusses the appropriate consumption quantities, the consumption safety of L, side effects and future research directions.

Biomarkers of carotenoid bioavailability

The use of biomarkers constitutes an essential tool to assess the bioavailability of carotenoids in humans. The present article aims to review several methodological, host-related and modulating factors relevant on assessing and interpreting carotenoid bioavailability. Markers for carotenoid bioavailability can be broadly divided into direct, biochemical or "analytical" markers and indirect, physiological or "functional" indicators. Analytical markers usually refer to biochemical indicators of intake and/or status (short and long term exposure) while functional measures may be interpreted in terms of cumulative exposure, biological effect (bioactivity) or modification of risk factors. Both types of markers display advantages and limitations but, in general, a relationship exists among the type of marker, the biological specimen needed and the time required for a change. Humans may absorb a wide range of carotenes and xanthophylls and many of them may be found in serum and tissues. However, under physiological conditions, the several classes of dietary carotenoids may behave unequally leading to a different systemic profile and, moreover, they can be selectively accumulated at target tissues. In addition, some carotenoids may be chemically and enzymatically modified generating different oxidative metabolites and apocarotenoids. Quantitatively, the biological response upon carotenoid intervention (assessed by analytical and functional markers) is highly variable but the use of large doses and long-term protocols may lead to saturation effects and the loss of linearity in the response. Also, despite carotenoid exposition is considered to be safe, markers of overexposure include clinical signs (i.e. carotenodermia, corneal rings and retinopathy) and biochemical indicators (hypercarotenemia, xanthophyll esters). Overall, both host-related and methodological factors may influence analytical and functional markers to assess carotenoid bioavailability although the different subclasses of carotenoids may not be equally affected.

Interaction of light quality and fertility on biomass, shoot pigmentation and xanthophyll cycle flux in Chinese kale

BACKGROUND

Nutritionally important carotenoids in 21-day-old brassica microgreens increase following short and long-term exposure to narrow-band wavelengths from light-emitting diodes (LED). The present study aimed to measure the impact of: (1) fluorescent/incandescent light and different percentages of blue/red LED light and (2) different levels of nutrient fertility on biomass and pigment concentrations in 30-day-old 'Green Lance' Chinese kale (Brassica oleracea var. alboglabra). Kale plants were exposed to four light treatments and two fertility levels and were harvested 30 days after seeding and analyzed for nutritionally important shoot pigments.

RESULTS

Kale under the fluorescent/incandescent light treatment had a significantly higher shoot fresh and dry mass. The shoot tissue concentrations of most pigment were significantly higher under blue/red LED light treatments. The higher fertility level resulted in higher concentrations for most pigments. Interestingly, the pool of xanthophyll cycle pigments and de-epoxidized xanthophylls was higher under all LED treatments.

CONCLUSION

The results obtained in the present study support previous data demonstrating the stimulation of nutritionally important shoot tissue pigment concentrations following exposure to sole source blue/red LEDs compared to traditional lighting. Xanthophyll cycle flux was impacted by LEDs and this may support the role of zeaxanthin in blue light perception in leafy specialty crops. © 2016 Society of Chemical Industry.

Environment and genotype effects on antioxidant properties of organically grown wheat varieties: a 3-year study

BACKGROUND

Wheat grain (Triticum aestivum L.) possesses significant amounts of antioxidants that contribute to the dietary antiradical protection against a number of chronic diseases. Despite the increasing interest in organic food among both consumers and scientists, the availability of literature studies concerning the environment effect under organic management is still scarce. The aim of this study was to evaluate the antioxidant properties of wheat varieties by considering the genotype response to different environmental factors under biodynamic management.

RESULTS

The soluble fraction of phenolic compounds was mainly determined by the environment, whereas a major genotypic effect was observed for the bound forms, which were present at higher amounts in red grain varieties. Moreover, a predominant effect of genotype was observed for yellow pigment content and antioxidant activity determined by the FRAP method. Despite some changes induced by environment, most genotypes had stable antioxidant properties and different phenolic profiles as determined by high-performance liquid chromatography-mass spectrometry, except for the old variety Inallettabile, which was the most sensitive to environmental fluctuations.

CONCLUSION

The red grain varieties Andriolo, Gentil rosso and Verna were identified as the most promising breeding material for the development of varieties with high nutraceutical value under low-input management. © 2016 Society of Chemical Industry.

Development of an Advanced HPLC-MS/MS Method for the Determination of Carotenoids and Fat-Soluble Vitamins in Human Plasma

The concentration of carotenoids and fat-soluble vitamins in human plasma may play a significant role in numerous chronic diseases such as age-related macular degeneration and some types of cancer. Although these compounds are of utmost interest for human health, methods for their simultaneous determination are scarce. A new high pressure liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS) method for the quantification of selected carotenoids and fat-soluble vitamins in human plasma was developed, validated, and then applied in a pilot dietary intervention study with healthy volunteers. In 50 min, 16 analytes were separated with an excellent resolution and suitable MS signal intensity. The proposed HPLC-MS/MS method led to improvements in the limits of detection (LOD) and quantification (LOQ) for all analyzed compounds compared to the most often used HPLC-DAD methods, in some cases being more than 100-fold lower. LOD values were between 0.001 and 0.422 µg/mL and LOQ values ranged from 0.003 to 1.406 µg/mL, according to the analyte. The accuracy, precision, and stability met with the acceptance criteria of the AOAC (Association of Official Analytical Chemists) International. According to these results, the described HPLC-MS/MS method is adequately sensitive, repeatable and suitable for the large-scale analysis of compounds in biological fluids.

Development of an Advanced HPLC-MS/MS Method for the Determination of Carotenoids and Fat-Soluble Vitamins in Human Plasma

The concentration of carotenoids and fat-soluble vitamins in human plasma may play a significant role in numerous chronic diseases such as age-related macular degeneration and some types of cancer. Although these compounds are of utmost interest for human health, methods for their simultaneous determination are scarce. A new high pressure liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS) method for the quantification of selected carotenoids and fat-soluble vitamins in human plasma was developed, validated, and then applied in a pilot dietary intervention study with healthy volunteers. In 50 min, 16 analytes were separated with an excellent resolution and suitable MS signal intensity. The proposed HPLC-MS/MS method led to improvements in the limits of detection (LOD) and quantification (LOQ) for all analyzed compounds compared to the most often used HPLC-DAD methods, in some cases being more than 100-fold lower. LOD values were between 0.001 and 0.422 µg/mL and LOQ values ranged from 0.003 to 1.406 µg/mL, according to the analyte. The accuracy, precision, and stability met with the acceptance criteria of the AOAC (Association of Official Analytical Chemists) International. According to these results, the described HPLC-MS/MS method is adequately sensitive, repeatable and suitable for the large-scale analysis of compounds in biological fluids.

Overall skin tone and skin-lightening-improving effects with oral supplementation of lutein and zeaxanthin isomers: a double-blind, placebo-controlled clinical trial

Purpose

Carotenoids, especially lutein and zeaxanthin isomers (L/Zi), filter blue light and protect skin from environmental factors including high-energy sources. These carotenoids may be able to block the formation of melanin pathways, decrease cytokines, and increase antioxidants.

Subjects and methods

This is a randomized, double-blind, placebo-controlled clinical trial over a 12-week supplementation period. Fifty healthy people (50 healthy subjects were recruited and 46 subjects completed the study) (males and females, age: 18–45 years) with mild-to-moderate dry skin were included in this study. Skin type of the subjects was classified as Fitzpatrick skin type II–IV scale. Subjects were administered with either an oral dietary supplement containing 10 mg lutein (L) and 2 mg zeaxanthin isomers (Zi) (L/Zi: RR-zeaxanthin and RS (meso)-zeaxanthin) or a placebo daily for 12 weeks. The minimal erythemal dose and skin lightening (L*) were measured via the Chromameter^®. The individual typological angle was calculated. Subjective assessments were also recorded.

Results

Overall skin tone was significantly improved in the L/Zi group compared to placebo (P<0.0237), and luminance (L*) values were significantly increased in the L/Zi group. Mean minimal erythemal dose was increased with L/Zi supplementation after 12 weeks of supplementation. L/Zi supplementation significantly increased the individual typological angle.

Conclusion

L/Zi supplementation lightens and improves skin conditions.

Lutein and zeaxanthin supplied by red/orange foods and fruits are more closely associated with macular pigment optical density than those from green vegetables in Spanish subjects

Lutein and zeaxanthin (L+Z) accumulate in the retina. Although vegetables are major contributors to their intake, a stronger association between fruits and macular pigment optical density (MPOD) has been reported. We hypothesized that L+Z intake from fruits would have a stronger association with L+Z status markers (MPOD, serum concentrations) than intake from vegetables or eggs, and that those associations would also differ according to plant foods color. One hundred eight subjects (57 men; age groups, 20-35 and 45-65 years) were enrolled in a cross-sectional study. L+Z intake from fruits, vegetables, and eggs was determined using three 24-hour diet recalls and a country-specific carotenoid database. Vegetables were the major contributors (75%) to L+Z intake, followed by eggs (10%) and fruits (4%). Vegetables supplied 86% and 84% of the LandZ intake, respectively, and fruits supplied 3% and 16%. Green foods supplied 78% and 52% of LandZ, respectively, followed by red/orange (9% and 38%) and white/yellow (14% and 9%). Factorial analysis showed associations in older subjects. The explained variance of the first 2 principal components was 54% considering L+Z intake from fruits, vegetables, and eggs, and 55% considering L+Z intake from plant foods grouped by color. Macular pigment optical density is related to L+Z intake from fruits (0.264, P=.003) and is independent of that from vegetables and eggs. It is related to L+Z intake from red/orange foods (0.320, P=.000) and the serum concentrations to that from green foods (0.222, P=.11). Although vegetables and green foods of plant origin are the major contributors to L+Z intake, red/orange foods and fruits have the strongest relationship to MPOD in study participants (45-65 years of age).

Assessment of lutein and zeaxanthin status and dietary markers as predictors of the contrast threshold in 2 age groups of men and women

Lutein and zeaxanthin (L + Z) status is associated with the macular pigment (MP). The relationship between MP and visual function is controversial. We hypothesized that, within the framework of nutrition, visual function was related to MP and nutritional and/or/dietary factors influencing it. A cross-sectional study was performed in 108 volunteers divided into 2 age groups (20-35 years; 45-65 years), each 27 women and 27 men, to assess the relationship between MP optical density (MPOD) and contrast threshold (CT), considering the influence of L + Z and, fruit and vegetable (F + V) intake. MPOD, L + Z in serum and dietary intake were determined using heterochromatic flicker photometry, high-performance liquid chromatography and 3-day food records, respectively. CT was measured with the CGT-1000 Contrast Glaretester at 6 stimulus sizes, with and without glare. Spearman correlation coefficient and a generalized linear model were used for the statistical study. MPOD and CT were higher and lower, respectively in younger than in elder individuals (P < .000) and were correlated only in the older group. CT were higher under glare conditions, at the intermediate and smaller visual angles, with greater differences in the older (P < .003) than the younger group (P < .014). In the total sample, CT correlated inversely with MPOD (correlation coefficients and P values ranging from -.245 to -.152 and from .000 to .026, respectively) and directly with F + V intake (correlation coefficients and P values ranging from -.265 to -.176 and from .000 to .010, respectively). As predictors of CT in the total sample, MPOD, F + V (every 100 g/d) and sex were identified (β coefficients ranged from -0.01 to -1.86; from 0.01 to 0.08 and from 0.01 to 0.40, respectively). CT revealed age-specific nutritional predictors: MPOD and serum lutein in the 45- to 65-year group, and F + V intake in the 20- to 35-year group.

Assessment of dietary lutein, zeaxanthin and lycopene intakes and sources in the Spanish survey of dietary intake (2009-2010)

We assessed the intake and major dietary sources of lutein, zeaxanthin and lycopene (non-provitamin A carotenoids) in Spain using food consumption data from the Spanish National Dietary Intake Survey (2009-2010). Three-day diaries and one 24-h recall were used to collect dietary data and a software application that includes HPLC data was used. Average intake of those carotenoids was 4290.8 μg/d (67.1% total carotenoid intake), mainly from vegetables (3414.0 μg/d), followed by fruits (393.5 μg/d), oils/fats (204.0 μg/d) and eggs/egg products (170.0 μg/d). Main sources of lutein and zeaxanthin were vegetables (62.9% total diet, 1235.2 μg/person/d). Lycopene intake was 3055.6 μg/d (71.2% of non-provitamin A carotenoids), mainly from tomato and by-products (86.3%) and watermelon. Red- and orange-colored fruits and vegetables were the major contributors of non-provitamin carotenoids (3219.0 μg/person/d). Balanced diets should favor fruits and vegetables over other dietary sources (oils, eggs, processed foods) that contain components to be consumed with moderation.

Lutein, Zeaxanthin, and meso-Zeaxanthin in the Clinical Management of Eye Disease

Lutein, zeaxanthin, and meso-zeaxanthin are xanthophyll carotenoids found within the retina and throughout the visual system. The retina is one of the most metabolically active tissues in the body. The highest concentration of xanthophylls is found within the retina, and this selective presence has generated many theories regarding their role in supporting retinal function. Subsequently, the effect of xanthophylls in the prevention and treatment of various eye diseases has been examined through epidemiological studies, animal studies, and clinical trials. This paper attempts to review the epidemiological studies and clinical trials investigating the effects of xanthophylls on the incidence and progression of various eye diseases. Observational studies have reported that increased dietary intake and higher serum levels of lutein and zeaxanthin are associated with lower risk of age-related macular degeneration (AMD), especially late AMD. Randomized, placebo-controlled clinical trials have demonstrated that xanthophyll supplementation increases macular pigment levels, improves visual function, and decreases the risk of progression to late AMD, especially neovascular AMD. Current publications on the preventive and therapeutic effects of lutein and zeaxanthin on cataracts, diabetic retinopathy, and retinopathy of prematurity have reported encouraging results.

Chitosan/poly-γ-glutamic acid nanoparticles improve the solubility of lutein

The aim of this study was to improve the solubility of lutein through the use of chitosan (CS)/poly-γ-glutamic acid (γ-PGA) nanoencapsulation. In terms of redispersibility, water-soluble chitosan (WsCS)/γ-PGA nanoparticles (NPs) were better than insoluble chitosan (InCS)/γ-PGA NPs. The lutein-loaded WsCS/γ-PGA NP has a spherical form with a size around 200nm and a narrow size distribution (PDI<0.1). Solubility measures showed that nanoencapsulation of lutein into WsCS/γ-PGA NPs resulted in a significant 12-fold higher solubility compared to that of non-nanoencapsulated lutein (p<0.05). The redispersibility index of the lutein-loaded NPs was 1.01, indicating that they were completely reconstituted into aqueous solution as same as original aqueous solution. These results suggest that WsCS/γ-PGA nanoencapsulation can be used to enhance the solubility of lutein and other poorly water-soluble compounds.

Phenolic profile and antioxidant potential of wild watercress (Nasturtium officinale L.)

Phenolic profile, antioxidant potential and pigment contents of wild watercress (Nasturtium officinale L.) were studied to assess the potential for future studies and its applications in neutraceuticals and bioactive functional ingredients. Different extracts of watercress (roots, stem and leaves) were analysed for pigment composition, total phenolic contents, and radical scavenging activity. The phenolic profile of the leaves and roots was studied using reversed phase HPLC-DAD. Results showed that total phenolic compounds in all samples were higher in the methanolic extracts than its corresponding aqueous extracts. The RSA of methanolic extracts was higher than aqueous extracts. Fourteen phenolic compounds were identified in the leaves, where coumaric acid and its derivatives, caftaric acid and quercetin derivatives were present in higher amounts. In roots, a total of 20 compounds was tentatively identified, with coumaric acid and its derivatives, sinapic acid, caftaric acid and quercetin derivatives were the major phenolic compounds. In conclusion, watercress has significant antioxidant activity and contains important phenolic compounds, which could be of potential biological interest.

Carotenoid Content in Organically Produced Wheat: Relevance for Human Nutritional Health on Consumption

In this study, 33 spring and winter wheat genotypes were analyzed for carotenoid content and composition. Investigated genotypes were divided into four genotype groups i.e., spelt, landraces, old cultivars and primitive wheat. The results showed a high level of variation among the genotypes in amount of carotenoids in the grain with high values (around 4 mg/Kg) especially in one of the genotypes—Öland 8. Lutein was the most common carotenoid in all the investigated genotypes, contributing 70%–90% of the carotenoids in the grain. Variation in carotenoid content and composition was found not only among genotypes, but also between genotype groups and wheat type, although there is a need to analyze more genotypes to confirm the differences found between groups and types. This study showed that 40% of the daily requirements of lutein can be achieved from the genotypes with the highest lutein content (Öland 8) produced using organic farming through the average human consumption of 200 grams of wheat per day. Furthermore, this study showed, by the use of principal component analyses, an opportunity to select genotypes combining high values of certain nutritional compounds. By a further breeding and commercial production of such genotypes, the nutritional value of wheat flour for human consumption can be improved.

Effect of ultrasonic waves on the stability of all-trans lutein and its degradation kinetics

Ultrasound treatment has been widely applied in the extraction of biologically active compounds including carotenoids. However, there are few reports on their effects on the stability of these compounds. In the present study, the stability of all-trans lutein, one of the carotenoids, was investigated under the action of ultrasound. Results showed that ultrasound induced the isomerization of all-trans lutein to its isomers, namely to 13-cis lutein, 13'-cis lutein, 9-cis lutein and 9'-cis lutein as analyzed by HPLC coupled with DAD and LC-MS; and the percentage of the isomerization increased with increasing both ultrasonic frequency and power. The stability of all-trans lutein in dichloromethane was worst among multiple kinds of solvents. Interestingly, the retention rate of all-trans lutein improved as the temperature increased, which runs counter to the Arrhenius law. Under ultrasound irradiation, the degradation mechanism might be different with various temperatures, the degradation of all-trans lutein followed first-order kinetics at 20°C, while second-order kinetics was followed at 30-50°C. As the ultrasonic reaction time prolonged, lutein epoxidation nearly occurred. Those results presented here emphasized that UAE techniques should be carefully used in the extraction of all-trans lutein.

Isolation and Analysis of the Cppsy Gene and Promoter from Chlorella protothecoides CS-41

Phytoene synthase (PSY) catalyzes the condensation of two molecules of geranylgeranyl pyrophosphate to form phytoene, the first colorless carotene in the carotenoid biosynthesis pathway. So it is regarded as the crucial enzyme for carotenoid production, and has unsurprisingly been involved in genetic engineering studies of carotenoid production. In this study, the psy gene from Chlorella protothecoides CS-41, designated Cppsy, was cloned using rapid amplification of cDNA ends. The full-length DNA was 2488 bp, and the corresponding cDNA was 1143 bp, which encoded 380 amino acids. Computational analysis suggested that this protein belongs to the Isoprenoid_Biosyn_C1 superfamily. It contained the consensus sequence, including three predicted substrate-Mg²⁺ binding sites. The Cppsy gene promoter was also cloned and characterized. Analysis revealed several candidate motifs for the promoter, which exhibited light- and methyl jasmonate (MeJA)-responsive characteristics, as well as some typical domains universally discovered in promoter sequences, such as the TATA-box and CAAT-box. Light- and MeJA treatment showed that the Cppsy expression level was significantly enhanced by light and MeJA. These results provide a basis for genetically modifying the carotenoid biosynthesis pathway in C. protothecoides.

A fast isocratic liquid chromatography method for the quantification of xanthophylls and their stereoisomers

A fast isocratic liquid chromatography method was developed for the simultaneous quantification of eight xanthophylls (13-Z-lutein, 13'-Z-lutein, 13-Z-zeaxanthin, all-E-lutein, all-E-zeaxanthin, all-E-canthaxanthin, all-E-β-apo-8'-carotenoic acid ethyl ester and all-E-β-apo-8'-carotenal) within 12 min, compared to 90 min by the conventional high-performance liquid chromatography method. The separation was achieved on a YMC C30 reversed-phase column (100 mm x 2.0 mm; 3 μm) operated at 20°C using a methanol/tert-butyl methyl ether/water solvent system at a flow rate of 0.8 mL/min. The method was successfully applied to quantify lutein and zeaxanthin stereoisomers in egg yolk, raw and cooked spinach, and a dietary supplement. The method can be used for the rapid analysis of xanthophyll isomers in different food products and for quality control purposes.

Forming a lutein nanodispersion via solvent displacement method: the effects of processing parameters and emulsifiers with different stabilizing mechanisms

A solvent displacement method was used to prepare lutein nanodispersions. The effects of processing parameters (addition method, addition rate, stirring time and stirring speed) and emulsifiers with different stabilizing mechanisms (steric, electrostatic, electrosteric and combined electrostatic-steric) on the particle size and particle size distribution (PSD) of the nanodispersions were investigated. Among the processing parameters, only the addition method and stirring time had significant effects (p<0.05) on the particle size and PSD. For steric emulsifiers, Tween 20, 40, 60 and 80 were used to produce nanodispersions successfully with particle sizes below 100nm. Tween 80 (steric) was then chosen for further comparison against sodium dodecyl sulfate (SDS) (electrostatic), sodium caseinate (electrosteric) and SDS-Tween 80 (combined electrostatic-steric) emulsifiers. At the lowest emulsifier concentration of 0.1%, all the emulsifiers invariably produced stable nanodispersions with small particle sizes (72.88-142.85nm) and narrow PSDs (polydispersity index<0.40).

Lutein production from biomass: marigold flowers versus microalgae

Microalgae have faster growth rates and more free lutein than marigold flowers, the current source of lutein. However, no commercial lutein production uses microalgae. This review compares lutein content, cultivation, harvesting, cell disruption, and extraction stages of lutein production using marigold flowers and those using microalgae as feedstock. The lutein production rate of microalgae is 3-6 times higher than that of marigold flowers. To produce 1 kg of pure lutein, marigolds need more land and water, but require less nutrients (N, P, K) and less energy than microalgae. Since lutein is tightly bound in microalgae and microalgae are small, cell disruption and subsequent extraction stages consume a considerable amount of energy. Research and development of affordable lutein production from microalgae are discussed.

Effects of nitrogen source availability and bioreactor operating strategies on lutein production with Scenedesmus obliquus FSP-3

In this study, the effects of the type and concentration of nitrogen sources on the cell growth and lutein content of an isolated microalga Scenedesmus obliquus FSP-3 were investigated. With batch culture, the highest lutein content (4.61 mg/g) and lutein productivity (4.35 mg/L/day) were obtained when using 8.0 mM calcium nitrate as the nitrogen source. With this best nitrogen source condition, the microalgae cultivation was performed using two bioreactor strategies (namely, semi-continuous and two-stage operations) to further enhance the lutein content and productivity. Using semi-continuous operation with a 10% medium replacement ratio could obtain the highest biomass productivity (1304.8 mg/L/day) and lutein productivity (6.01 mg/L/day). This performance is better than most related studies.

Role of macular xanthophylls in prevention of common neovascular retinopathies: retinopathy of prematurity and diabetic retinopathy

Retinopathy of prematurity (ROP) and diabetic retinopathy (DR) are important causes of blindness among children and working-age adults, respectively. The development of both diseases involves retinal microvascular degeneration, vessel loss and consequent hypoxic and inflammatory pathologic retinal neovascularization. Mechanistic studies have shown that oxidative stress and subsequent derangement of cell signaling are important factors in disease progression. In eye and vision research, role of the dietary xanthophyll carotenoids, lutein and zeaxanthin, has been more extensively studied in adult onset macular degeneration than these other retinopathies. These carotenoids also may decrease severity of ROP in preterm infants and of DR in working-age adults. A randomized controlled clinical trial of carotenoid supplementation in preterm infants indicated that lutein has functional effects in the neonatal eye and is anti-inflammatory. Three multicenter clinical trials all showed a trend of decreased ROP severity in the lutein supplemented group. Prospective studies on patients with non-proliferative DR indicate serum levels of lutein and zeaxanthin are significantly lower in these patients compared to normal subjects. The present review describes recent advances in lutein and zeaxanthin modulation of oxidative stress and inflammation related to ROP and DR and discusses potential roles of lutein/zeaxanthin in preventing or lessening the risks of disease initiation or progression.

An Evidence-Based Systematic Review of Lutein by the Natural Standard Research Collaboration

An evidence-based systematic review of lutein by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

Relationship between lutein and mycotoxin content in durum wheat

Levels of lutein and a number of mycotoxins were determined in seven varieties of durum wheat (Triticum durum) and two varieties of common wheat (Triticum aestivum) in order to explore possible relationships amongst these components. Durum wheat cultivars always showed both higher lutein and mycotoxin contents than common wheat cultivars. The mycotoxins detected in both common and durum wheat cultivars were produced by the genera Fusarium, Claviceps, Alternaria and Aspergillus. Fusarium was the major producer of mycotoxins (26 mycotoxins) followed by Claviceps (14 mycotoxins), which was present only in some cultivars such as Chevalier (common wheat), Lupidur and Selyemdur (both durum wheat), Alternaria (six mycotoxins) and Aspergillus (three mycotoxins). Positive correlations between the levels of lutein and mycotoxins in durum wheat cultivars were found for the following mycotoxins: deoxynivalenol (DON), its derivative DON-3-glucoside, moniliformin, culmorin and its derivatives (5-hydroxyculmorin and 15-hydroxyculmorin).