Dietary Carotenoids Research Articles

Physicochemical and nutritional properties of yogurt emulsion with lycopene during chilled storage.

Lycopene is a highly potent antioxidant that is prevalent among dietary carotenoids. However, its use in food formulations is restricted due to its poor water-solubility and proneness to oxidation. The aim of this research was to encapsulate lycopene in yogurt using emulsion technology for improving its stability during processing and storage, in order to diversify a widely consumed food product and enhance its nutritional value. Confocal laser microscopy data showed that the incorporation of oil droplets with emulsification did not have a negative effect on the formation and microstructure of yogurt. Syneresis of lycopene-fortified yogurt samples was approximately twice as high compared with plain yogurt at day 7; the ability to retain water was significantly improved with storage time for all emulsified samples. Additionally, storage reduced the Turbiscan Stability Indices (TSI) for all yogurt samples, which suggests that physical stability improved at 4°C. Emulsification resulted in increased oxidation levels due to increased oil content. This effect was ameliorated by lycopene encapsulation, which effectively protected corn oil from oxidation and prevented degradation. This study indicates that emulsification is a promising method for lycopene encapsulation and can be used for developing yogurt with desirable nutritional properties.

Systematic review of carotenoid concentrations in human milk and infant blood.

Dietary carotenoid intake is associated with vitamin A status and healthy visual and cognitive function in early life. To date, however, only limited population-level data on the concentrations of carotenoids in human milk or infant blood have been available to assess the dietary exposure of infants to carotenoids. This systematic review seeks to define worldwide carotenoid concentrations in human milk and infant blood. The PubMed, Embase, and Web of Science databases were searched for original research articles published before February 2021. Dietary carotenoid concentrations in human milk and in blood plasma or serum from healthy infants (≤1 year of age), along with study location, infant age, and lactation stage, were extracted. Means and 95%CIs were analyzed within and across variables. Publications on carotenoid concentrations in infant blood (47 publications, n = 4553 unique individuals) and human milk (65 publications, n = 2871 unique individuals) described populations from 22 and 31 countries, respectively. Carotenoid species concentrations ranged from 0.3 to 20 µg/dL in blood and from 0.1 to 30 µg/dL in human milk, with carotenoid concentrations generally decreasing in milk across lactation stages and increasing in blood with infant age. Concentrations of the major dietary carotenoids-β-carotene, lycopene, lutein, β-cryptoxanthin, zeaxanthin, and α-carotene-have been reported in both infant blood and human milk across infant ages and lactation stages, with β-carotene, lutein, and lycopene tending to be more abundant than other carotenoids. Despite heterogeneous amounts of data available for each outcome, infants worldwide are exposed to a variety of dietary carotenoids. The estimates of dietary carotenoids in human milk and infant blood can facilitate the interpretation of future studies and the design of nutritionally relevant experiments on dietary carotenoids and infant health.

Carotenoid intake during early life mediates ontogenetic colour shifts and dynamic colour change during adulthood

Carotenoids play an import role as one of the most prevalent pigments in animals. Carotenoid-based coloration accounts for striking sexually and naturally selected colour adaptations. Several anurans (frogs and toads) change body coloration either slowly and permanently between life stages (ontogenetic colour change), or rapidly and temporarily within minutes or hours (dynamic colour change). We investigated ontogenetic colour change from orange to green morphs in the Wallace's flying frog, Rhacophorus nigropalmatus , and tested the influence of dietary carotenoids on colour change during postmetamorphic development. At the age of 9 months, while all individuals still possessed orange-red body coloration, a 20-week-long feeding experiment was performed by supplying the frogs with either no carotenoid supplements or dietary carotenoids once or four times per week. A high carotenoid diet resulted in a faster increase in green colour chroma as well as higher levels of green and carotenoid chroma of back coloration. Less or no carotenoid supplementation led to an increase in UV-blue chroma, contributing to a dull turquoise appearance often observed in captive-bred and captive-raised anurans. In addition, we showed for the first time that Wallace's flying frogs also perform dynamic colour changes. We tested dynamic changes triggered either by 2 min tactile handling or varying 1 h dark and light conditions. Our results demonstrate that a high carotenoid diet facilitates rapid and reversible change of body coloration in response to a tactile stressor, an adaptation absent in frogs receiving no carotenoids. Dynamic colour changes were likewise observed in response to changing light conditions presumably camouflaging individuals and providing protection from UV irradiation. The ontogenetic and dynamic pigmentation changes are discussed in relation to mechanism and as a likely strategy to avoid predation both at different life stages and in different environments. • Dietary carotenoids impact the development of the green back coloration of frogs. • Lack of carotenoids increase UV-blue chroma, contributing to turquoise appearance. • Early life acquisition of carotenoids regulates dynamic colour change behaviour. • Light conditions mediate reversible full and partial body colour change of frogs.

Tunisian Opuntia ficus-indica fruit peels: biochemical and microbiological characterization and possible applications

In Tunisia, the number of prickly pear seed oil companies is currently increasing. However, a large amount of prickly pear fruit by-products is discarded. Proper utilization of these by-products, in particular fruit peels, could lead to the obtaining of a new important source of nutraceutical compounds. This investigation was aimed at conducting a phytochemical screening and assessing the antibacterial properties of prickly pear peels cultivar ‘orange’. These samples were analyzed fresh and oven-dried at 45 °C to develop concepts for applications in the food industry as potential sources of fibers and antimicrobial “green” additives. The proximate compositions of both prickly pear peels were determined along with total phenolic compounds, carotenoids, and antioxidant activity. Free phenolic compounds were determined using liquid chromatography coupled with mass spectrometry. Furthermore, the antibacterial effectiveness of the prickly pear peel extracts was tested against selected foodborne pathogens. The highest concentrations of dietary fiber (22.7 g/100 g d.m.) and carotenoids 10.90 mg/100 g d.m. were observed in oven-dried prickly pear peels, which also showed the highest inhibition of the DPPH radicals. The antibacterial activities showed a relevant growth inhibition against Bacillus cereus and a partial inhibition against Staphylococcus aureus. Prickly pear peel is a neglected nutritional and antibacterial source that should be widely valued as food additive.

Role of Dietary Carotenoids in Frailty Syndrome: A Systematic Review.

Unbalanced diets and altered micronutrient intake are prevalent in the aging adult population. We conducted a systematic review to appraise the evidence regarding the association between single (α-carotene, β-carotene, lutein, lycopene, β-cryptoxanthin) or total carotenoids and frailty syndrome in the adult population. The literature was screened from study inception to December 2021, using six different electronic databases. After establishing inclusion criteria, two independent researchers assessed the eligibility of 180 retrieved articles. Only 11 fit the eligibility requirements, reporting five carotenoid entries. No exclusion criteria were applied to outcomes, assessment tools, i.e., frailty constructs or surrogates, recruitment setting, general health status, country, and study type (cohort or cross-sectional). Carotenoid exposure was taken as either dietary intake or serum concentrations. Cross-sectional design was more common than longitudinal design (n = 8). Higher dietary and plasma levels of carotenoids, taken individually or cumulatively, were found to reduce the odds of physical frailty markedly, and the evidence showed consistency in the direction of association across all selected studies. Overall, the methodological quality was rated from moderate (27%) to high (73%). Prevention of micronutrient deficiencies has some potential to counteract physical decline. Considering carotenoids as biological markers, when monitoring micronutrient status, stressing increased fruit and vegetable intake may be part of potential multilevel interventions to prevent or better manage disability.

Association of dietary and plasma carotenoids with urinary F2-isoprostanes.

Carotenoids may protect against chronic diseases including cancer and cardiometabolic disease by mitigating oxidative stress and/or inflammation. We cross-sectionally evaluated associations between carotenoids and biomarkers of oxidative stress or inflammation. From 2003 to 2009, the Sister Study enrolled 50,884 breast cancer-free US women aged 35-74. Post-menopausal participants (n = 512) were randomly sampled to measure carotenoids and biomarkers of oxidative stress. Dietary carotenoid consumption was assessed using a validated 110-item Block 1998 food frequency questionnaire; use of β-carotene-containing supplements was also assessed. Plasma carotenoids were quantified, adjusting for batch. Urinary markers of lipid peroxidation, 8-iso-prostaglandin F2α (8-iso-PGF2α) and its metabolite (8-iso-PGF2α-M) were also measured. Since the biomarker 8-iso-PGF2α can reflect both oxidative stress and inflammation, we used a modeled 8-iso-PGF2α to prostaglandin F2α ratio approach to distinguish effects reflecting oxidative stress versus inflammation. Multivariable linear regression was used to assess the associations of dietary and plasma carotenoids with the estimated biomarker concentrations. Total plasma carotenoids were inversely associated with 8-iso-PGF2α-M concentrations (P for trend across quartiles = 0.009). Inverse trends associations were also seen for α-carotene and β-carotene. In contrast, lutein/zeaxanthin showed associations with both 8-iso-PGF2α and 8-iso-PGF2α-M concentrations. The inverse association for total carotenoids appeared to be specific for oxidative stress (chemical 8-iso-PGF2α; Phighest vs. lowest quartile = 0.04 and P for trend across quartiles = 0.02). The pattern was similar for α-carotene. However, lutein/zeaxanthin tended to have a stronger association with enzymatic 8-iso-PGF2α, suggesting an additional anti-inflammatory effect. Supplemental β-carotene was inversely associated with both 8-iso-PGF2α and 8-iso-PGF2α-M concentrations, as well as with both chemical and enzymatic 8-iso-PGF2α. Dietary carotenoids were not associated with either biomarker. Plasma carotenoids and supplemental β-carotene were associated with lower concentrations of 8-iso-PGF2α metabolite. Plasma carotenoids associations may reflect antioxidant effects.

The Effects of Lutein and Zeaxanthin Supplementation on Cognitive Function in Adults With Self-Reported Mild Cognitive Complaints: A Randomized, Double-Blind, Placebo-Controlled Study.

BackgroundLutein and zeaxanthin are fat-soluble, dietary carotenoids with high concentrations in human brain tissue. There have been a number studies confirming an association between lutein and zeaxanthin and cognitive function.PurposeExamine the effects of lutein and zeaxanthin supplementation on cognitive function in adults with self-reported cognitive complaints.Study DesignTwo-arm, parallel-group, 6-month, randomized, double-blind, placebo-controlled trial.MethodsNinety volunteers aged 40–75 years received either 10 mg of lutein and 2 mg of zeaxanthin, once daily or a placebo. Outcome measures included computer-based cognitive tasks, the Cognitive Failures Questionnaire, Behavior Rating Inventory of Executive Function, Profile of Mood States, and the Patient-Reported Outcomes Measurement Information System-29.ResultsCompared to the placebo, lutein and zeaxanthin supplementation was associated with greater improvements in visual episodic memory (p = 0.005) and visual learning (p = 0.001). However, there were no other statistically-significant differences in performance on the other assessed cognitive tests or self-report questionnaires. Lutein and zeaxanthin supplementation was well-tolerated with no reports of significant adverse effects.ConclusionThe results from this trial suggest that 6-months of supplementation with lutein and zeaxanthin may improve visual memory and learning in community-dwelling adults with self-reported cognitive complaints. However, it had no other effect on other computer-based measures of cognitive performance or self-report measures of cognition, memory, mood, or physical function.

Lutein and Zeaxanthin and Their Roles in Age-Related Macular Degeneration-Neurodegenerative Disease.

Lutein and zeaxanthin belong to the xanthophyll family of carotenoids, which are pigments produced by plants. Structurally, they are very similar, differing only slightly in the arrangement of atoms. Key sources of these carotenoids include kale, savoy cabbage, spinach, broccoli, peas, parsley, corn, and egg yolks. The recommended daily intake of lutein is approximately 10.0 mg and that of zeaxanthin is 2 mg. Lutein intake in adults varies, with average intakes being 1–2 mg/day. Due to the lack of synthesis of consumption of these compounds in humans, these substances are extremely important for the proper functioning of certain organs of the body (eye, skin, heart, intestines). Eating a lot of dark leafy vegetables and some fruits can help to prevent our bodies from developing diseases. The protective effects of carotenoids are mainly related to their defense against oxidative stress and their ability to scavenge free radicals. Lutein and zeaxanthin are the only dietary carotenoids that accumulate in the retina, specifically the macula, and are called macular pigments. These carotenoids are concentrated by the action of specific binding proteins such as StARD3, which binds lutein, and GSTP1, which binds zeaxanthin and its dietary metabolite, mesozeaxanthin. It has been shown that supportive therapy with lutein and zeaxanthin can have a beneficial effect in delaying the progression of eye diseases such as age-related macular degeneration (AMD) and cataracts. This article presents the current state of knowledge on the role of lutein and zeaxanthin, especially from human studies targeting their metabolism and bioavailability, with recommendations to consume xanthophyll-rich foods.

Dietary effects on the reproductive performance of the sea urchin Tripneustes gratilla l: Implications for broodstock conditioning

Broadcast spawning animals often display differential parental contributions within aquaculture environments, which can influence offspring performance through a loss of genetic variation in cultured populations. This study aimed to assess the effect of different feeding regimes on the reproductive performance of Tripneustes gratilla. To achieve this, broodstock animals were conditioned on four diets [formulated feed, kelp (Ecklonia maxima), green seaweed (Ulva lacinulata) and mixture of the three diets] for four months, and various broodstock traits, including gonad development, gonad coloration, gamete (egg and sperm) quality, egg energetic components and egg fatty acids were assessed. In this study, broodstock animals fed natural feeds and a mixed feeding regime had greater gonad and egg redness indices, possibly as a result of dietary carotenoids being incorporated into their gonads. These pigments have known antioxidant, anti-inflammatory, pro-vitamin A, photoprotection and immunity-related roles. Results from this study showed that a formulated feed (20U) should not be fed in isolation for reproductive purposes, as these broodstock animals displayed lower gonad and egg quality indices. Furthermore, this diet showed poor fatty acid provisioning, with an excess linoleic acid being detected in eggs. In contrast, animals fed a mixed diet displayed the most diverse egg fatty acid profile, with a high proportion of fatty acids commonly found in sea urchins, such as palmitic acid, myristic acid and the omega-3 eicosapentaenoic acid. These results indicate that conditioning broodstock on natural feeds is advantageous for sea urchin gonad development and reproductive performance.

Transcriptome and co-expression network analyses provide insights into fruit shading that enhances carotenoid accumulation in pomelo (Citrus grandis)

Carotenoids are indispensable for human health, and citrus fruit are a crucial source of dietary carotenoids. Bagging, an important orchard practice to enhance fruit economic value, is widely used in many horticultural crops, including citrus fruit. The bagged ‘Majiayou’ pomelo (Citrus grandis) produces vivid deeper red pulp, a fantastic agronomic trait, but the underlying molecular regulatory mechanism remains largely unexplored. Here, the enhancement of carotenoids, especially lycopene, was confirmed by HPLC analysis of carotenoids in the pulp of bagged fruit and controls. qRT-PCR analysis of the 14 carotenoid pathway genes further revealed that upregulated PSY and downregulated CCD1 expression in bagged fruit could directly enhance the accumulation of carotenoids. In addition, RNA-seq analysis identified 311 differentially expressed genes (DEGs) in the bagged fruit and controls in five developmental stages. Weighted gene co-expression network analysis (WGCNA) identified 13 critical candidate genes among the DEGs, which are closely associated with lycopene accumulation. The underlying regulatory mechanism of these candidate genes on the transcription of carotenoid pathway genes in the bagged fruit was discussed. Considering that the candidate genes were involved in the corresponding metabolic pathways, the increase in sucrose content and decrease in ABA in bagged fruit were also identified, implying that these candidate genes may be indirectly related to carotenoid enhancement in pulp by regulating phytohormones, primary metabolism, and stress responses. The results provide new insights into the potential regulatory mechanism of lycopene enhancement in the pulp of bagged ‘Majiayou’ pomelo, facilitating breeding and orchard management efforts to improve the nutritional quality and esthetic value of citrus, and perhaps other fruit crops.

Dietary fatty acid composition affects the apparent digestibility of algal carotenoids in diets for Atlantic salmon, Salmo salar

Astaxanthin (Axn) is the most commonly used carotenoid to enhance the flesh colouration of salmonids, which is one of the key criteria perceived to reflect the freshness and nutritional quality of the product and consequently affecting its price. However, the digestibility of astaxanthin by salmonids is highly variable, ranging between 20% and 60%. Axn digestibility can also be affected by total dietary lipid content and fatty acid (FA) composition (saturated FAs [SFA], mono-unsaturated FAs [MUFA] or poly-unsaturated FAs [PUFA]). This experiment contained four diets fed to juvenile Atlantic salmon for 2 weeks. Two diets formulated with either synthetic or algal carotenoids combined with poultry oil and two additional diets containing algal carotenoids with either tallow or canola oil. The aim of this study was to compare the feed intake, as a measure of diet palatability, and apparent digestibility (AD) of Axn between the two diets containing either synthetic or algal carotenoids. Results showed that algal carotenoids had significantly higher AD than synthetic Axn and that high levels of SFA, such as those in tallow, may inhibit the AD of algal carotenoids. Meanwhile, the high levels of MUFA and, in particular 18:1n-9, in canola oil significantly improved the AD of algal carotenoids for Atlantic salmon. This study demonstrates the utility of algal carotenoids as natural pigment alternatives for farmed salmon, particularly beneficial when combined with different oil sources that contain more 18:1n-9, such as in canola, and less SFA, such as in tallow, in order to optimize the utilization of dietary carotenoids.

Dietary Carotenoids in Head and Neck Cancer-Molecular and Clinical Implications.

Head and neck cancer (HNC) is one of the most common cancers in the world according to GLOBCAN. In 2018, it was reported that HNC accounts for approximately 3% of all human cancers (51,540 new cases) and is the cause of nearly 1.5% of all cancer deaths (10,030 deaths). Despite great advances in treatment, HNC is indicated as a leading cause of death worldwide. In addition to having a positive impact on general health, a diet rich in carotenoids can regulate stages in the course of carcinogenesis; indeed, strong epidemiological associations exist between dietary carotenoids and HNS, and it is presumed that diets with carotenoids can even reduce cancer risk. They have also been proposed as potential chemotherapeutic agents and substances used in chemoprevention of HNC. The present review discusses the links between dietary carotenoids and HNC. It examines the prospective anticancer effect of dietary carotenoids against intracellular cell signalling and mechanisms, oxidative stress regulation, as well as their impact on apoptosis, cell cycle progression, cell proliferation, angiogenesis, metastasis, and chemoprevention; it also provides an overview of the limited preclinical and clinical research published in this arena. Recent epidemiological, key opinion-forming systematic reviews, cross-sectional, longitudinal, prospective, and interventional studies based on in vitro and animal models of HNC also indicate that high carotenoid content obtained from daily supplementation has positive effects on the initiation, promotion, and progression of HNC. This article presents these results according to their increasing clinical credibility.

Effect of Dietary Carotenoids on Reproducers of Amazon River Prawn Macrobrachium amazonicum. Part 1: Metabolism, Morphometric / Zootechnical Indexes, Body Composition and Gametes

The inclusion of natural extracts and solution of synthetic astaxanthin in the Macrobrachium amazonicum diet were tested to verify their effect on performance, body indexes and total accumulation of astaxanthin in the reproductive tissues and gametes of this crustacean in comparison with newly captured wild animals. The experiment was randomized in blocks (five treatments with three replicates). Four groups were submitted, during 20 days, to diets in recirculation tanks: control diet (CONT); diet containing natural extract of “buriti” (CAR); diet with inclusion of natural “urucum” extract (BIXN), diet with synthetic astaxanthin (ASTX) and NATURAL group (not fed with ration). 180 prawns were used, with 60 males (6.08±1.96 g) and 120 females (4.55±1.03 g) distributed in five groups containing four males and eight females each. There were no significant differences in performance and body indexes. The number of released spermatozoids, live spermatozoids, body and egg pigmentation was higher in BIXN and ASTX treatments. The ASTX treatment was superior to the NATURAL group in the body pigmentation of females and eggs and release of spermatophores by males. These results demonstrate that the use of natural and artificial carotenoid pigments in the diet are beneficial for reproduction of M. amazonicum.

Effect of Dietary Carotenoids on Reproducers of Amazon River Prawn Macrobrachium amazonicum. Part 2: External Coloration, Accumulation of Astaxanthin in Body Tissues and Pigment Stability in Feed

The color is an important factor to distinguish the commercialized Amazon river prawns. The accumulation of pigments in the body can vary according to the prawn’s diet. In this work, ethanolic extracts of “buriti” and annatto rich in pigments were obtained and tested comparatively with synthetic astaxanthin in the feeding of adults of Macrobrachium amazonicum, together with a control group without pigments and a newly captured wild group. Levels of body pigments were measured using UV reflective spectroscopy and external staining by colorimetry. Differences were observed in the accumulation of astaxanthin in body tissues, differences in saturation between genders and that annatto extract has greater stability in the feed after water immersion (P˂0.05). Further studies are recommended to verify the ideal dosage of natural pigments in relation to synthetic astaxanthin that benefits the productive development of prawns.

Skin Carotenoid Status of Black/African American College Students Correlates with Plasma Carotenoids and Fruit and Vegetable Intake Independent of Skin Tone

Background: Skin carotenoids measured by reflection spectroscopy (RS) score as a biomarker of fruit and vegetable (F/V) intake has not been used extensively in USA minority populations, and there are concerns about the impact of skin tone on the validity of skin carotenoid scores as a biomarker of F/V intake. Methods: The aim of this study was to examine the relationship between skin carotenoids measured by RS score, plasma carotenoids, dietary carotenoids, and F/V intake in African American/Black college students and explore the effect of skin tone on RS score readings. One hundred African American/Black students at a Historically Black Colleges and Universities institution participated in this study. RS score was assessed by Veggie Meter, plasma carotenoids measured by high performance liquid chromatography, and dietary carotenoids and F/V intake were estimated by a weekly food frequency questionnaire (FFQ). Skin tone was matched visually and read using a skin swatch on a scale of 1-15, 1 being the lightest and 15 being the darkest. Correlations between RS scores with total plasma carotenoid concentrations, dietary carotenoids, and F/V intake were examined. Multiple linear regression analysis was conducted to assess the relationship of skin tone at the fingertip and inner arm, BMI, and %body fat on the correlation between RS and total plasma carotenoid levels. Results: Skin carotenoid levels indicated by RS scores were correlated with total plasma carotenoid concentrations (R= 0.595, p

The Role of Glucosinolates from Cruciferous Vegetables (Brassicaceae) in Gastrointestinal Cancers: From Prevention to Therapeutics.

The gastrointestinal (GI) tract is composed of rapidly renewing cells, which increase the likelihood of cancer. Colorectal cancer is one of the most frequently diagnosed GI cancers and currently stands in second place regarding cancer-related mortality. Unfortunately, the treatment of GI is limited, and few developments have occurred in the field over the years. With this in mind, new therapeutic strategies involving biologically active phytocompounds are being evaluated as anti-cancer agents. Vegetables such as broccoli, brussels sprouts, cabbage, cauliflower, and radish, all belonging to the Brassicaceae family, are high in dietary fibre, minerals, vitamins, carotenoids, polyphenols, and glucosinolates. The latter compound is a secondary metabolite characteristic of this family and, when biologically active, has demonstrated anti-cancer properties. This article reviews the literature regarding the potential of Cruciferous vegetables in the prevention and/or treatment of GI cancers and the relevance of appropriate compound formulations for improving the stability and bioaccessibility of the major Cruciferous compounds, with a particular focus on glucosinolates.

The Genetic Components of a Natural Color Palette: A Comprehensive List of Carotenoid Pathway Mutations in Plants.

Carotenoids comprise the most widely distributed natural pigments. In plants, they play indispensable roles in photosynthesis, furnish colors to flowers and fruit and serve as precursor molecules for the synthesis of apocarotenoids, including aroma and scent, phytohormones and other signaling molecules. Dietary carotenoids are vital to human health as a source of provitamin A and antioxidants. Hence, the enormous interest in carotenoids of crop plants. Over the past three decades, the carotenoid biosynthesis pathway has been mainly deciphered due to the characterization of natural and induced mutations that impair this process. Over the year, numerous mutations have been studied in dozens of plant species. Their phenotypes have significantly expanded our understanding of the biochemical and molecular processes underlying carotenoid accumulation in crops. Several of them were employed in the breeding of crops with higher nutritional value. This compendium of all known random and targeted mutants available in the carotenoid metabolic pathway in plants provides a valuable resource for future research on carotenoid biosynthesis in plant species.

Dietary carotenoid intake and dental fluorosis in relation to SOD2 (rs 11968525) polymorphisms in Guizhou, China.

Genetic and dietary factors are important contributors to the development of dental fluorosis (DF). This study investigated the association between DF and dietary carotenoids, and explored whether the association was modified by polymorphisms of the antioxidant enzyme superoxide dismutase 2 (SOD2 rs11968525) in Guizhou, China. A cross-sectional study with a total of 899 adults aged 18-75 years were enrolled in the study. Face-to-face interviews were conducted to assess dietary habits using a validated 75 item food frequency questionnaire (FFQ). Sociodemographic and lifestyle information, and blood and urine samples were also collected. Genotypes were evaluated using TaqMan single nucleotide polymorphism (SNP) Genotyping Assay. There were significant dose-dependent inverse associations of the prevalence of DF with intake of α-carotene, β-carotene, lutein/zeaxanthin, lycopene and total carotenoids (p-trend ranged from <0.001-0.004). The odds ratios (ORs) and 95% confidence intervals (CIs) of DF comparing the highest against lowest quartile were 0.56 (0.35, 0.92) for α-carotene, 0.53 (0.35, 0.81) for β-carotene, 0.44 (0.27, 0.74) for lycopene, 0.35 (0.21, 0.58) for lutein/zeaxanthin in combination and 0.42 (0.25, 0.69) for total carotenoids (all p-trend<0.005). Intake of β-cryptoxanthin was not found to be related to DF. The inverse association of DF with dietary intake of α-carotene and β-carotene was more evident in individuals with the AG+AA genotype (p-interaction<0.05). Higher dietary carotenoids were associated with a lower occurrence of DF, polymorphisms in SOD2 (rs 11968525) modified the associations between dietary intake of carotene and DF. These findings provide evidence for precision prevention of fluorosis.

A fast and simplified method to estimate bioaccessibility of carotenoids from plant tissues.

Carotenoids are lipophilic isoprenoids with roles in photosynthesis and signaling. Dietary carotenoids are nutritionally relevant as precursors of retinoids (including vitamin A). These pigments also provide health benefits as anti-oxidative, anti-inflammatory or anti-tumor agents, among other biological functions. Such health-related advantages have spurred a strong interest in the biofortification of food products with carotenoids. Most biotechnological approaches have been carried out in plants because dietary carotenoids are primarily obtained from fruits and vegetables. Successful examples abound in the literature but in most cases a critical aspect is neglected: bioaccessibility. A higher content of carotenoids in a given plant product does not necessarily mean an improved dietary intake because these lipophilic compounds must be released from the food and incorporated into intestinal micelles to reach the sites of action in the human body. Bioaccessibility refers to the percentage of the carotenoid that is released from the food matrix during digestion and incorporated into micelles in the gastrointestinal tract. Bioaccessibility substantially changes depending on the physicochemical context and subcellular environment where carotenoids accumulate within plant cells. Here, we present a fast, simplified, inexpensive and efficient in vitro method to estimate bioaccessibility that has been adapted to the requirements and equipment of typical plant molecular biology labs. The availability of this protocol should improve biotechnological efforts aimed at carotenoid biofortification by complementing compositional improvements with bioaccessibility data to better estimate the nutritional value of the newly generated functional food.

Effect of Dietary Carotenoid on Egg Yolk Color and Singlet Oxygen Quenching Activity of Laying Hens.

The effects of dietary carotenoids on egg yolk were investigated in this study. Forty Rhode Island Red (RR) and 40 Silky Fowl (SF) hens that were 60 weeks old were used. Hens of each breed were randomly divided into four dietary groups. One group was fed a basal diet (crude protein 17%, metabolizable energy 2800 kcal/kg) only, whereas the other groups received a specific additive, namely, paprika extract, marigold petal extract, or Paracoccus cell powder, in addition to the same basal diet. The color and carotenoid content of egg yolk and singlet oxygen quenching activity were measured after 4 weeks. The total carotenoid content, zeaxanthin content, and singlet oxygen quenching activity in the yolk differed significantly between breeds and between diets (two-way ANOVA). The lutein content in egg yolk was affected by breed and diet, as well as by the interaction between these two factors. Regarding the Roche Yolk Color Fan values, only the effect of diet was significant. In terms of objective egg yolk color, there was a significant difference in lightness and yellowness between breeds. The total carotenoid content was higher in SF than in RR in all the groups. Likewise, the levels of zeaxanthin and lutein in the yolk were higher in SF than in RR (P<0.05). The results of the present study suggest that dietary carotenoids are effective feed additives for laying hens, especially SF, to improve the color and singlet oxygen quenching activity of egg yolk.