Pure Carotenoids Research Articles

A phyco-nanobionics biohybrid system for increased carotenoid accumulation in C. sorokiniana UUIND6.

Recent advancements in "phyco-nanobionics" have sparked considerable interest in the ability of microalgae to synthesize high-value natural bioactive compounds such as carotenoid pigments, which have been highlighted as an emergent and vital bioactive compound from both industrial and scientific perspectives. Such bioactive compounds are often synthesized by either altering the biogenetic processes existing in living microorganisms or using synthetic techniques derived from petroleum-based chemical sources. A bio-hybrid light-driven cell factory system was established herein by using harmful macroalgal bloom extract (HMBE) and efficient light-harvesting silver nanoparticles (AgNPs) to synthesize HMBE-AgNPs and integrating the synthesized HMBE-AgNPs in various concentrations (1, 2.5, 5 and 10 ppm) into the microalgae C. sorokiniana UUIND6 to improve the overall solar-to-chemical conversion efficiency in carotenoid pigment synthesis in microalgae. The current study findings found high biocompatibility of 5 ppm HMBE-AgNP concentration that can serve as a built-in photo-sensitizer and significantly improve ROS levels in microalgae (6.75 ± 0.25 μmol H2O2 g-1), thus elevating total photosynthesis resulting in a two-fold increase in carotenoids (457.5 ± 2.5 μg mL-1) over the native microalgae without compromising biomass yield. NMR spectroscopy was additionally applied to acquire a better understanding of pure carotenoids derived from microalgae, which indicated similar peaks in both spectra when compared to β-carotene. Thus, this well-planned bio-hybrid system offers a potential option for the cost-effective and long-term supply of these natural carotenoid bio-products.

Camelina sativa meal hydrolysate as sustainable biomass for the production of carotenoids by Rhodosporidium toruloides

BackgroundAs the circular economy advocates a near total waste reduction, the industry has shown an increased interest toward the exploitation of various residual biomasses. The origin and availability of biomass used as feedstock strongly affect the sustainability of biorefineries, where it is converted in energy and chemicals. Here, we explored the valorization of Camelina meal, the leftover residue from Camelina sativa oil extraction. In fact, in addition to Camelina meal use as animal feed, there is an increasing interest in further valorizing its macromolecular content or its nutritional value.ResultsCamelina meal hydrolysates were used as nutrient and energy sources for the fermentation of the carotenoid-producing yeast Rhodosporidium toruloides in shake flasks. Total acid hydrolysis revealed that carbohydrates accounted for a maximum of 31 ± 1.0% of Camelina meal. However, because acid hydrolysis is not optimal for subsequent microbial fermentation, an enzymatic hydrolysis protocol was assessed, yielding a maximum sugar recovery of 53.3%. Separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), and SSF preceded by presaccharification of Camelina meal hydrolysate produced 5 ± 0.7, 16 ± 1.9, and 13 ± 2.6 mg/L of carotenoids, respectively. Importantly, the presence of water-insoluble solids, which normally inhibit microbial growth, correlated with a higher titer of carotenoids, suggesting that the latter could act as scavengers.ConclusionsThis study paves the way for the exploitation of Camelina meal as feedstock in biorefinery processes. The process under development provides an example of how different final products can be obtained from this side stream, such as pure carotenoids and carotenoid-enriched Camelina meal, can potentially increase the initial value of the source material. The obtained data will help assess the feasibility of using Camelina meal to generate high value-added products.

Evaluation of Carotenoids Protection Against Oxidative Stress in the Animal Model Caenorhabditis elegans.

The nematode Caenorhabditis elegans is a versatile and powerful model organism for animal experimental research and, despite being an invertebrate, displays remarkably similar molecular bases and conserved cellular pathways to those of humans. Oxidative stress is an etiological factor that influences numerous diseases, degenerative processes and aging. C. elegans has revealed as an opportune and feasible organism to investigate the antioxidant effects of different bioactives or complex food matrices, and a number of protocols have been developed by using different oxidative stressors. Carotenoids are recognized as quenchers and scavengers of reactive oxygen species, and many of their related health benefits attributed in the diet are tightly linked to their antioxidant properties. In this chapter, we report a simple and rapid assay to evaluate the protection capacity of pure carotenoids or complex carotenoid extracts against oxidative stress in the model system C. elegans. The protocol describes a representative feeding experiment by adding carotenoids to the nematode growth medium and after an incubation period, the C. elegans populations fed with carotenoids are exposed to an acute oxidative stress by using H2O2 as oxidative agent. The protection against oxidative stress is evaluated as the survival rate of the nematodes fed with the carotenoid prior to receiving oxidative treatment compared with the survival rate of control nematode population. In order to confirm the carotenoid intake by the nematodes during the feeding experiment a bioassimilation experiment is also reported.

Comparison of β-carotene and Spirulina (Arthrospira platensis) in mullet (Mugil liza) diets and effects on antioxidant performance and fillet colouration

The addition of pure carotenoids is a common practice in some aquaculture species production since its use in fish feed is known to improve carcass and antioxidant capacity. Spirulina (Arthrospira) cyanobacteria are a rich source of carotenoids that has proven health benefits for fish welfare. In the current experiment, four isonitrogenous (38%) isolipidic (9%) diets were made, including a control diet (free of β-carotene and Spirulina, SP0), β-carotene diet (50 mg kg−1, β0), and two Spirulina (Arthrospira platensis) diets with 2% (SP2) and 4% (SP4) of total feed inclusion. The experimental diets were given to juvenile mullets in a controlled recirculation system. The parameters evaluated were growth, colour, total carotene content of muscle, and antioxidant capacity of the liver and muscle. Significant differences were found (p < 0.05) in the final weight, specific growth rate, and feed conversion ratio between the SP0 treatment and the β0, SP2, and SP4 treatments. The colorimetric analysis showed that the redness and carotene deposition in muscle of mullet is statistically the same between β0 and SP4. Mullets fed with Spirulina (SP2 and SP4 treatments) had a statistical higher antioxidant capacity against radical peroxyls in liver tissue, showing lower lipid peroxidation (TBARS). In conclusion, Spirulina can be a suitable substitute for pure β-carotene addition in fish diets, improving some of the health benefits from this carotene.

Effect of divalent minerals on the bioaccessibility of pure carotenoids and on physical properties of gastro-intestinal fluids

During digestion, high concentrations of divalent minerals (DMs) can lead to insoluble lipid–soap complex formation, hampering carotenoid bioaccessibility. The effect of varying concentrations (0–1000mg/L) of calcium, magnesium, zinc and sodium (control) on the bioaccessibility of lutein, neoxanthin, lycopene and β-carotene, following in vitro gastro-intestinal digestion (GI), was investigated systematically and coupled with physical measurements of the digesta. Addition of DMs significantly decreased (p<0.001) carotenoid bioaccessibility, up to 100% in the case of calcium. Mean half maximal inhibitory concentrations (EC50) for calcium, magnesium and zinc were 270±18, 253±75 and 420±322mg/L respectively. Increased DM concentrations correlated with decreased viscosity (r>0.9) and decreased carotenoid bioaccessibility. Surface tension of digesta correlated inversely (p<0.05) with the bioaccessibility of carotenoids. This correlation was mineral and carotenoid dependent. Although based on in vitro findings, it is plausible that similar interactions occur in vivo, with DMs affecting the bioaccessibility and bioavailability of carotenoids and other lipophilic micronutrients and phytochemicals.

Effects of physicochemical properties of carotenoids on their bioaccessibility, intestinal cell uptake, and blood and tissue concentrations

Carotenoid bioavailability is affected by numerous factors. Our aim was to assess the involvement of known carotenoid physicochemical properties (e.g.,hydrophobicity, van der Waals volume,…) on the transport of the main dietary carotenoids (β-carotene, lycopene, lutein, and astaxanthin, from their food matrix to their main storage tissues. We used four complementary models: synthetic mixed micelles, an in vitro digestion procedure, Caco-2 cell monolayers, and a gavage experiment in rats. The efficiency with which pure carotenoids were incorporated into synthetic mixed micelles was related to their melting points (r =0.99, p =0.015). The efficiency with which pure carotenoids were transferred from dietary triglycerides into mixed micelles was related to carotenoid hydrophobicity (r =-1, p =0.005). There was no relationship between the carotenoid physicochemical properties studied and their uptake efficiency by Caco-2. The postprandial plasma carotenoid response to carotenoid gavage was related to carotenoid hydrophobicity (r = -0.99, p =0.006). Carotenoid adipose tissue response was not related to the carotenoid physicochemical properties studied. Thus, carotenoid hydrophobicity is important for bioaccessibility and postprandial blood response of carotenoids. In contrast, the carotenoid physicochemical properties studied are apparently not strong determinants of carotenoid uptake by enterocytes and adipose tissue.

Enhancement of the Photocatalytic Activity of TiO2 Nanoparticles by Water-Soluble Complexes of Carotenoids

Photoirradiation of TiO(2) nanoparticles by visible light in the presence of the water-soluble natural polysaccharide arabinogalactan complexes of the hydrocarbon carotenoid β-carotene leads to enhanced yield of the reactive hydroxyl (OH) radicals. The electron paramagnetic resonance (EPR) spin-trapping technique using α-phenyl-N-tert-butyl nitrone (PBN) as the spin-trap has been applied to detect this intermediate by trapping the methyl and methoxy radicals generated upon reaction of the hydroxyl radical with dimethylsulfoxide (DMSO). The free radicals formed in this system proceed via oxygen reduction and not via the reaction of holes on the TiO(2) surface. As compared with pure carotenoids, carotenoid-arabinogalactan complexes exhibit an enhanced quantum yield of free radicals and stability toward photodegradation. The observed enhancement of the photocatalytic efficiency for carotenoid complexes, as measured by the quantum yield of the desired spin adducts, arises specifically from the decrease in the rate constant for the back electron transfer to the carotenoid radical cation. These results are important for a variety of TiO(2) applications, namely, in photodynamic therapy, and in the design of artificial light-harvesting, photoredox, and catalytic devices.

Water Soluble Complexes of Carotenoids with Arabinogalactan

We present the first example of water soluble complexes of carotenoids. The stability and reactivity of carotenoids in the complexes with natural polysaccharide arabinogalactan were investigated by different physicochemical techniques: optical absorption, HPLC, and pulsed EPR spectroscopy. Compared to pure carotenoids, polysaccharide complexes of carotenoids showed enhanced photostability by a factor of 10 in water solutions. A significant decrease by a factor of 20 in the reactivity toward metal ions (Fe(3+)) and reactive oxygen species in solution was detected. On the other hand, the yield and stability of carotenoid radical cations photoproduced on titanium dioxide (TiO(2)) were greatly increased. EPR measurements demonstrated efficient charge separation on complex-modified TiO(2) nanoparticles (7 nm). Canthaxanthin radical cations are stable for approximately 10 days at room temperature in this system. The results are important for a variety of carotenoid applications, in the design of artificial light-harvesting, photoredox, and catalytic devices.

Effects of Heating and Illumination on Trans−Cis Isomerization and Degradation of β-Carotene and Lutein in Isolated Spinach Chloroplasts

The influence of thermal treatment and light exposure on degradation and isomerization of the predominant carotenoids (lutein and beta-carotene) occurring in green leafy vegetables was assessed. The effect of lipid addition on carotenoid stability was also evaluated. For the first time, the stabilities of pure carotenoids and chloroplast-bound carotenoids were compared. Besides degradation, heating caused carotenoid isomerization in all samples. Whereas pure carotenoids favor 13-cis isomers, in native chloroplasts and heated chloroplasts 9-cis isomers were predominant. Illumination of freshly prepared chloroplast isolates caused an initial increase in the level of lutein (9.6%) and beta-carotene (29.8%), while pure carotenoids exhibited time-dependent degradation. The addition of lipids to chloroplast preparations had the reverse effects on the retention of both carotenoids after heating; isomerization was not significantly affected. It was demonstrated that carotenoid stability has to be evaluated for every individual pigment in its genuine environment. Stability data based on model systems (e.g., pure carotenoids) may not be transferred to complex food matrices without intensive investigation.

Plasma appearance of labeled β-carotene, lutein, and retinol in humans after consumption of isotopically labeled kale

The bioavailability of carotenoids from kale was investigated by labeling nutrients in kale with 13C, feeding the kale to seven adult volunteers, and analyzing serial plasma samples for labeled lutein, beta-carotene, and retinol. Ingested doses of labeled carotenoids were 34 micromol for beta-carotene and 33 micromol for lutein. Peak plasma concentrations, areas under the plasma concentration-time curves (AUCs), and percentages of dose recovered at peak plasma concentrations were calculated. Average peak plasma concentrations were 0.38, 0.068, and 0.079 microM for [13C]lutein, [13C]beta-carotene, and [13C]retinol, respectively. Average AUC values (over 28 days) were 42.8, 13.6, 13.2 microM h for [13C]lutein, [13C]beta-carotene, and [13C]retinol, respectively. Percentages of dose recovered at peak plasma concentrations were 3.6, 0.7, and 0.7% for [13C]lutein, [13C]beta-carotene, and [13C]retinol, respectively. A positive relationship was observed between baseline plasma retinol levels and [13C]retinol plasma response. It is possible that this relationship was mediated either through some aspect of beta-carotene absorption or via the common pathways of metabolism for postdose and endogenous retinoid.

Effect of carotenoids against genotoxicity of diethylnitrosamine on rat hepatocytes

Carotenoids have been considered as special nutrients due to their biological activity as provitamin A compounds, and because of their natural antioxidant and anticarcinogenic properties. The main objective of this study was to evaluate the protective effect of carotenoids against the genotoxic cellular damage induced by diethylnitrosamine (DEN), a potent hepatocarcinogen. Normal and freshly isolated hepatocytes were cultured as the biological system. Concentrations of 2.5 and 5 μ m DEN caused 1.3 and 2.0 times more DNA T 3H incorporation, respectively, when compared with control cells. Pure carotenoids, β-carotene (50 μ m), lutein (1 μ m) and a carotenoid extract from green peppers (1 μ m eq. lutein) were used as functional nutrients to protect the cells. All the carotenoids studied prevented the genotoxic damage caused by 2.5 μ m DEN. When 5 μ m DEN was used, only β-carotene and the pepper extract inhibited the damage up to 30–40%. Carotenoids provide a dose-dependent protective effect against DNA damage induced by DEN in isolated hepatocytes.

Silver ion spray reagent for the discrimination of β- and ε-end groups in carotenoids on thin-layer chromatograms

Thin-layer chromatograms of pure carotenoids and natural carotenoid mixtures were dried and sprayed with saturated methanolic silver nitrate solution. Those carotenoids containing β-end groups showed a marked bathchromic colour change for each such end group. Thus, β-carotene, β-cryptoxanthin and zeaxanthin gave a clear red colour while α-carotene, α-cryptoxanthin and lutein gave deep organge spots after such treatment. Taraxanthin and antheraxanthin could be similarly distinguished. The method was not applicable to paper chromatography.

Carotenoids in diets for salmonids: II. Epimerization studies with astaxanthin in Atlantic salmon

Atlantic salmon ( Salmo salar, L.), kept in sea pens were fed diets containing pure carotenoids. No significant preferential utilization of the (3 S,3′ S), (3R,3′ S) or (3R,3′ R) optical isomers of astaxanthin was observed. No epimerization occurred in the flesh at the chiral centres at C-3 and C-3′ in astaxanthin.

Carotenoids as a Source of Pigmentation in Juvenile Lobsters Fed a Purified Diet

Pigmentation of cultured lobsters is dependent upon the presence of dietary carotenoids. Inclusion of pure or crude carotenoids in a purified diet results in the accumulation of exoskeleton pigments tentatively identified by thin-layer chromatography and spectrophotometric analysis as primarily astaxanthin and β-carotene. Despite the lack of de novo synthesis pure carotenoids such as β-carotene, echinenone, and canthaxanthin are transformed into astaxanthin. The level of pigmentation produced by these biosynthetic precursors is related to the proximity to the astaxanthin end product. A carotenoid extract from crayfish waste dissolved in cod liver oil, and oleoresin paprika were effective in producing pigmentation. Rationale for the choice and use of carotenoid sources for incorporation into artificial feeds to produce natural pigmentation of cultured lobsters is discussed.

The biosynthesis of astaxanthin. XVIII. The metabolism of the carotenoids in the prawn, Penaeus japonicus bate.

The biosynthesis of astaxanthin in the prawn was further studied using pure carotenoids and preparations obtained from natural sources. Zeaxanthin, obtained from the Chinese lantern, was fed to the prawn, Penaeus japonicus Bate. Astaxanthin was biosynthesized from zeaxanthin, thus indicating the existence of a second pathway to astaxanthin in the prawn. Canthaxanthin and astaxanthin from crab waste were respectively metabolized to and absorbed as body astaxanthin in the prawn. Pigmented preparations from corn gluten, alfalfa and Spirulina (blue-green alga) were found to increase the body astaxanthin to various degrees.

The metabolism of β-carotene and other carotenoids in the brine shrimp, Artemia Salina L. (Crustacea: Branchiopoda)

1. 1. The only cartenoids present in the egges and freshly-hatched nauplii of Artemia salina are echinenone and canthaxanthin. 2. 2. A method for feeding pure carotenoids to carotenoid-depleted adult Artemia is described. 3. 3. Pure β-carotene is converted into echinonen and canthaxanthin by Artemia; the kinetics of changes in pigment composition after feeding suggest that echinenone is an intermediate in the conversion of β-carotene into canthaxanthine. 4. 4. Animals fed pure echinenone convert this into canthaxanthin. 5. 5. Canthaxanthin is the final product of these carotenoid transformations in Artemia; no intermediates in its formation, other than echinenone, were detected. 6. 6. Zeaxanthin is absorbed by the gut, but is not metabolized to yield ketocarotenoids. 7. 7. The results are discussed in the light of other studies on carotenoid distribution in the Branchiopoda, and their contribution to our understanding of the mechanism of ketocarotenoid formation is assessed.

Carotenoid metabolism in Artemia salina L.

1. 1. The carotenoid metabolism in Artemia salina has been studied with the feeding of algae Chaetoceras gracilis and pure carotenoids. 2. 2. Artemia salina was unable to metabolize β-carotene to astaxanthin beyond canthaxanthin. 3. 3. The major carotenoid of Artemia salina fed Chaetoceras gracilis, β-carotene, echinenone and canthaxanthin was canthaxanthin. Astaxanthin was not found in all groups. 4. 4. Light did not affect the quantity of total carotenoids, but accelerated the accumulation of canthaxanthin.

The carotenoid pigments of Daphnia magna straus—I. The pigments of animals feed Chlorella pyrenoidosa and pure carotenoids

1. 1. Animals fed the alga Chlorella pyrenoidosa were found to contain β-carotene, echinenone, canthaxanthin, one or more unidentified ketocarotenoids and astaxanthin, in addition to small amounts of lutein, the latter pigment being present only in the gut wall. 2. 2. Similar pigments were found in wild populations of D. magna and of other species of Cladocera. 3. 3. It was suggested that ketonic carotenoids found in the animals were metabolic products derived from ingested β-carotene, and this was confirmed by feeding pure carotenoids. The results of these experiments indicated that the animal is able to form echinenone, canthaxanthin and astaxanthin, in that order, from β-carotene. 4. 4. Isocryptoxanthin and isozeaxanthin are metabolized to echinenone and canthaxanthin respectively, but α-carotene and lutein are not converted to β-carotene derivatives.

Studies with a Natural Source of Xanthophylls for the Pigmentation of Egg Yolks and Skin of Poultry

Abstract THE two major natural sources of xanthophylls in poultry diets are yellow corn and alfalfa. In addition, many materials such as pimiento pepper (Brown, 1930), dehydrated lettuce meal (Schaible et al., 1954), clover meal (Ratcliff et al., 1961) and pure synthetic carotenoids (Steinegger and Zanetti, 1957; Steinegger et al., 1957; Marusich et al., 1960) have been studied for their pigmentation potential for incorporation in poultry diets to augment the dietary concentration of pigments. In Mexico a source of supplementary xanthophylls is particularly necessary because the major portion of available grains used for poultry feed is markedly deficient in pigments as measured in terms of beta-carotene (white corn 0.0021, white milo 0.0017, yellow milo 0.0017, red milo 0.0071; Brambila et al., 1961). In Mexico, as in many other countries, a deep pigmentation of both egg yolks and skin of poultry is preferred by the consumer. The present paper reports the results…

Studies on Animal Carotenoids

ABSTRACT The principal carotenoids of the trout are b-carotene, lutein and astacene. Carotenoids occur in the skin, muscles, ovary, liver and eyes, but the different types are distributed in a characteristic way in the various tissues. Carotene is found in significant amounts only in the liver and ovaries; lutein and astacene together in the skin, muscles and ovaries; lutein alone in the eyes. Xanthophylls, mainly lutein, occur also in the liver. Other carotenoids occur in trace amounts only. The lutein and astacene of skin are in the form of esters. They are located in the xanthophores and erythrophores, of which they are the characteristic pigments. Yellow areas of skin yield mainly lutein, red areas mainly astacene, and their concentration in all parts of the skin is normally several times greater than in any other tissue. In muscle and ovaries both lutein and astacene are present as free hydroxy-carotenoids. Liver contains both free and esterified xanthophylls, the eye tissues only esters. The concentration of the different carotenoid fractions in various tissues was measured with a photoelectric colorimeter in terms of standard preparations of pure carotenoids. Direct measurements of the absorption spectra of xanthophores and erythrophores show that the former contain only lutein, the latter only astacene. Living xanthophores show absorption maxima at 487, about 450 and at 425 mμ; erythrophores a single maximum close to 490 mμ. The maxima in the blue-green are displaced some 10 –12 mμ towards the red from their positions in hexane. The concentration of pigment in fully contracted chromatophores was estimated by a visual matching method. Xanthophores were found to contain about 0 ·00001 –0 ·00003 γ of lutein per cell, erythrophores about 0 ·00020 –0 ·00035 γ per cell. Trout kept on a diet low in carotenoids lose most of their red and yellow pigments. Astacene disappears from the skin, and the lutein falls to about one-sixth of the normal level. Feeding with natural foods rich in carotenoids may restore the skin coloration, and fish reared on a natural diet develop normal wild-type pigmentation. Supplements of pure carotenoids added to the basal diet failed to raise the pigment levels of depigmented fish. Trout do not appear to be able to convert one type of carotenoid to another.