Science topic
Carotenoids - Science topic
Carotenoids are the general name for a group of fat-soluble pigments found in green, yellow, and leafy vegetables, and yellow fruits. They are aliphatic hydrocarbons consisting of a polyisoprene backbone.
Questions related to Carotenoids
Dear all,
I’m performing an untargeted analysis of carotenoids in different matrices by means of HPLC-DAD, but I have not all the zis isomers standards for comparing my UV-visible spectra, so I wonder if there is any available library that I could use with my Chemstation software.
Thank you very much on advance.
I have performed GC-MS analysis of Phytochemicals from a medicinal plants and also identified compound using NIST library. After NIST identification, I have a list of compounds. I am constructing a phytoconstituent table for manuscript which include compound name, retention time, area percentage, molecular formula and nature of compounds. I am trying to identify the class/nature of phytochemicals (like flavonoids, carotenoids, phenols or polyphenols, glycosides, tannins etc). For that, I am searching each compounds on databases like PlantaeDB, IMPPAT 2.0, website like MedChemExpress and also literature search. Some compounds can be find here but many of the are not to be found anywhere.
1. How to identify the class of phytochemicals or secondary metabolites after GC_MS and NIST identification?
2. Some compounds are repeated with different retention time and Similarity index. Which one to include and on what basis?
3. In one extract, more than 60 compounds are identified. Should I include them all for manuscript or can I select the important and bioactive compounds only?
Very much thankful for your help!
I used the Lichtenthaler and Wellburn (1983) protocol for chlorophyll and carotenoid extraction, using 0.5 g of fresh leaves, 10 mL of 80% acetone, and the coefficients and equations from this protocol. However, the final carotenoid results were negative. Is there any explanation for this? Could I have made a mistake in the protocol? I have followed this protocol many times, but this is the first time this has occurred.
I need to know how to determine carotenoid content in extracted shrimp waste sample and hope to use extracts as food ingredient. but here unavailable the carotenoid standards to determine carotenoid content using spectrophotometer and HPLC
Dear Colleagues!
I am interested in ELSD, an HPLC detector.
Is there anyone who is currently using or has used this detector?
I would appreciate it if you could share information on the problems, concerns, and advantages of using it in real world situations.
It would also be appreciated if you could introduce, for example, review articles explaining the characteristics of quantitative measurements of analogous compounds without their standards.
I would like express my gratitude to everyone in this community.
I appreciate it.
Best regards,
Yasuhiro Nishida
Hi, my name is Anna.
I am working on the extraction of polyphenols and carotenoids from date seeds using NADES.
I am centrifuging the samples at 14400 rpm-20min-10ºC but when I remove the supernatant, the liquid looks cloudy.
What could I do to remove those particles that can interfere in the assays? Perform a filtration on paper?
Thanks for your help and best regards,
Anna
I am standardizing a UV-VIS screening method that allows me to quantify provitamin A carotenoids. The results will be compared with samples quantified by HPLC, which is my Gold Standard. Nevertheless; the results that I've gotten so far using both methods aren't comparable between each other. I was expecting the concentration using both methods would be similar, sadly this is not happening. Interestingly, when I multiply the concentrations I get in my colorimetric method by a factor of 4.5 ish, they are very similar to the ones in HPLC. You might say that maybe the calculations are not correct, but I considered the dilution factor as well.
Has anybody encountered this issue, if so... Let's talk about it
In D. salina in which beta carotene is accumulated throughout the cells, staining with iodine reagent will cause the whole cell to be stained.
NOTE: These pictures are copyright. No reproduction without written permission from the publisher.


I want to identify carotenoid pigment (polar one) isolated from bacteria. Many articles suggested to use LC-MS. However we do nit have reference samples? so is it possible to conduct a LC-MS analysis without a reference?
I am working with chitosan application and I have found increased concentration of chlorophyll, carotenoids and protein in plants treated with higher doses of chitosan. Whereas growth of plant like height was less in higher concentration and more in lower concentrations. I have done experiment twice for confirming my results and it is coming in the same way. Is it possible that stressed plant have more chlorophyll as compared to non-stressed plants.
Dear community of ResearchGate:
I am thinking about conducting a literature review study on a topic related to physico-chemical or nutritional parameters in peppers (Capsicum spp.). Even though, as I am a beginner in this field, I am not sure what topic to focus the study on.
I woulg be grateful if could make some suggestions.
Thanks in advance!
Pablo
I'm using the standardised INFOGEST - Minekus (2014) consensus paper for my simulated in vitro digestion model but each time I use the digesta (intact, diluted 1:4 and 1:8) on the caco-2 cells to assess carotenoid uptake and transport, the cell viability is less than 10% based on the MTT assay. I strongly suspect the bile salt concentration I'm using could be toxic to the cells. Is there a step by step procedure I can use without necessarily using the test kit to verify the actual concentration of my bile salts?
There are several ways to extract microbial carotenoids. according to you what is the best ways to extract carotenoids from microbes?
Hi to everyone!
I am going to to measure levels of total carotenoids in pepper fruits by means of a spectrophotometer. I would like to know which standard solution I should use in order to elaborate the calibration equation, and to express the result.
Thanks for your feedback!
Pablo
Hi everyone!
I project to mesure levels of various nutricional parameter in pepper fruits. Looking up in the literature, I found out the research article of Nagata and Yamashita (1992), in which a spectrophotometric method for analysis of chlorophyll and carotene in fruits is described.
I think that the information provided by Nagata and Yamashita (1992) could be very useful for our project. Even though, this paper is not written in English, but in Japanese (a language that, unfortunately, I do not understand).
As it is a highly cited study (1112 citations in Google Scholar, many of them from non-Japanese authors), I suspect that the procedure of Nagata and Yamashita (1992) must be detailed in English somewhere.
I would be grateful if someone could give me some light about this.
Thanks in advance!
Pablo Reguera
Literature cited:
Nagata M, Yamashita I (1992). Simple method for simultaneous determination of chlorophyll and carotenoids in tomato fruit. Nippon Shokuhin Kogyo Gakkaish 39 (10): 925-928.
T1-Chemical treatment
chl a=8.509, chl b= 14.833, carotenoids= 573.749, chl a/b ratio = 0.573
vs.
T2-Control (no treatmet)
chl a=9.563, chl b=16.945, carotenoids= 655.979, chl a/b ratio = 0.564
Hi!
I'm doing pigment analysis (chlorophylls and carotenoids) of seaweed, and I have some questions about the extraction and the reference system.
I'm not sure if I should use fresh or dry material for the extraction.
I understand that giving the results based on dry weight is a more reliable reference system than fresh weight since water content can vary depending on storage, but does that mean I have to use dry material for the extraction or can/should I use fresh material and then just convert the results to dry weight? (I'm doing dry matter content analysis already so I know the dry matter and water content). Hope my question makes sense.
Thank you!
I am sampling tree leaves for pigment analysis with a UV-Vis Spectrometer. The samples will be snap-frozen in the field and stored in the dark. I am trying to determine the best method for anthocyanin extraction and analysis. It would also be great to know if it could be integrated into a chlorophyll and carotenoid extraction too? Thanks in advance!
As I'm working on RP-UHPLC-DAD quantitative analysis of carotenoids in plant material, I have troubles with dissolving solid standards of carotenoids. I've tried mixtures of acetone and methanol or ethanol in different ratios, but nothing worked perfectly. Either it didn't dissolved at all, or it started to re-crystallize in the solution after few days/weeks. Does anyone have any experience?
Specifically, I'm talking about alpha-, beta- and gamma- carotene, lycopene, lutein, zeaxanthin and neoxanthin.
I mean the unit of expresion
Is it possible to measure carotenoid based on fluorescence image?
Somebody, if you have some references regarding carotenoid quantification by auto-fluorescence image, share to me please :)
In my experiment, I used a rhodamine filter (excitation 540-552 nm; emission: 575-640 nm) in H. pluvialis cell (microalgae), but the problem is the death cell also showed fluorescence.
Is it possible to use this filter to quantify carotenoids?
Thank you
- Rendi -
Does anyone know the appropriate equation for chlorophyll a, chlorophyll b,total chlorophyll & carotenoids extracted by DMSO
Dears,
I have used fresh leaves methods (1 g of the leaf tissues using 80% acetone) using these equations:
[Chl a (mg.g-1) = (13.95OD665−6.88OD649)V/200 W];
[Chl b (mg.g-1) = (24.96OD649− 7.32OD665)V/200W];
[Car. (mg.g-1) = (1000OD470−2.05Chl a−114.80Chl b) V/ (245×200 W)].
Where; Chl a– chlorophyll a, Chl b – chlorophyll b, Car. – carotenoid, V –volume, and W – sample weight.
what about dry leaves methods??
Hi!
Dear colleagues and respected seniors, I am searching for a biochemical reaction to identify the km and vmax values for the said enzyme, which converts alpha carotene into Lutein, but still I am not able to identify, so if anyone could help to find it, give me a reference article/ paper please, I will be very thankful to al of you.
Thanks and best regards
Mr. Rafi Ullah Khan
PhD candidate (Biotechnology)
Can anyone suggest the HPLC method to quantify spheroidenone carotenoid with a DAD detector and an Agilent zorbax SB-C18 column?
Astaxanthin is the carotenoid antioxidant.
I am working with carotenoids mainly Lutein and Zeaxanthin. For this I have purchased the standards from Sigma Aldrich which were very expensive. there are all in powder form and I would like to know what is the best solvent for dilution and long-term storage before HPLC analysis. I went through different papers and there was no consistency as there was mention of methanol, hexane, etc...
I would appreciate any technical and straightforward suggestion. Thanks
Conducting HPLC analysis for carotenoid content on vegetables is not an issue, but what about carotenoid content incorporated in a high fat diet ?
My lab usually performs double hexane extraction for common fruit and vegetables but what would be an appropriate extraction protocol for fat food (45% butter, 5% tomato powder) ?
I've heard two possibilities : extract as usual or sample saponification prior to analyses.
As carotenoids are lipophilic, wouldn't saponification damage these compounds ?
What would be an appropriate extraction protocol in such a case ?
Thanks for your help !
Can I extract carotenoid pigment from microalgae (C. sorokiniana and D. salina) without freeze-drying?
I already searched and read references about drying process that we can use heat-drying method but that wasn't recommended because could cause degradation of carotenoid content. So if I don't have a freeze-dryer, can still extract the pigments from wet biomass?
For a school project, we have to isolate carotenoids from fruit and a product from the fruit. For our research we use watermelon and we wanna have a look for lycopene and beta carotenoids. We already found a protocol for the watermelon itself. Unfortunately, we can find a protocol for alcoholic drinks. The measurement will be made by HPLC in a mobile phase ethanol:acetonitrile. (+ 0,1% diethyl ether). I hope anyone can help us.
Hello. I've been working on photosynthesis pigment content in in vitro grown trees and was examining the formulas for determining the concentration of chlorophyll a and b and carotenoids based on absorbance, i.e. using a spectrophotometer. I've found various formulas, and even though they all share the same general design: concentration=coefficient1*adsorbance1-coeficeint2*adsorbance2, the coefficients differ among sources. I was curious as to the reason behind this. Is it due to the use of different equipment, i.e. every spectrophotometer is different, or something else? I'm new to this field, thus any help, directions to relevant introductory literature, articles, would be great.
The metabolite that is extracted after evaporation of the solvent is purified using ethanol and ethyl acetate solvent by silica gel chromatography column.Is it possible that our carotenoids are oxidized at this distance, but all this is done in the dark?
I took 2 gm tissue and then added 20ml solvent. After that I collected supernatent and then made up volume 25 ml by about 10 ml hexane. I know absorbance reading and A1% value, I am a bit confused about total volume used amount. Would you someone assist me regarding that "V" value ?
Hi everyone! i am looking for protocols to evaluate the bioaccessibility of carotenoids in plant matrix. Ideally the best would be a quite easy protocol that could be used massively in the lab, but every advice is welcome! :)
Thank you very very much!
Best
L
I need to perform some tests with extracted carotene.
Hello everybody!
I have performed an acidic MeOH:HCl 1% (v/v) plant extraction from Arabidopsis leaves to calculate Anthocyanins concentrations based on:
Rabino, I., and Mancinelli, A. L. 1986. Light, temperature, and anthocyanin production. Plant Physiol. 81:922-924.
I want to calculate also Chl a, Chl b and Carotenoids concentrations from this acidic methanolic extraction. So far, I have only found 100% MeOH equations to calculate concentrations of these pigments, separately, but not a single reference to calculate them from a MeOH:HCl 1% (v/v) plant extract.
I have read that "A657 values provide an estimate of Chl content" (Photoregulation of Anthocyanin Synthesis' VIII. EFFECT OF LIGHT PRETREATMENTS, Mancinelli, 1983), but I would like to have a more precise value for Chl a, Chl b, and carotenoids also, if possible.
I have recorded measurements of wavelengths between 300-700 nm.
I would be grateful if anyone helps me with that.
Thank you all!
I want to know about different analytical methods (rapid) to determine carotenoids (carotene and Xanthophyll) in maize flour, which gives more accuracy.
These spots seem to disappear after they have been on land for a while and it seems nobody knows exactly what causes it. Some sources just say "carotenoid rich plumage", so is it similar to the way flamingos express reddish feathers with a carotenoids rich diet?
what is the reason for decrease of carotenoids in Cyperus leave, which is treated by 100 mg/L Heavy metal solution for about 26 days? It was almost 49 percent. if there is any article which could help me would be great.
I would appreciate in advance for your advice.
As we all know that there are number of methods for the estimation of leaf pigments mainly chlorophyll and carotenoids, but i want to know out of DMSO and acetone which method is best?
We are trying to isolate some carotenoids from algae with semi-prep HPLC. As literature says, a few mg will be enough. Is this true?
There are several methods for assessment of antioxidant activity, of which DPPH scavenging assay. DPPH has absorbance around 520nm, while carotenoids have absorbance near 500nm.
- I am testing the difference in carotenoids of 5 groups of diferent sex or development stage animals with one way ANOVA. My samples are from 13 the smallest to 44 the greatest. Do I use the eta square value?
So I use the Kruskall-Wallis test to compare the groups when the variables were not normally distributed, and the post-hoc Dunn test.
I'm looking for a way to remove carotenoids from a solution containing chlorophylls and carotenoids, except chromatography method.
thank you.
I am looking for a method to coat the carotenoid staphyloxanthin firmly on a tissue culture plate or membrane filter discs. Please share protocols or literature for this procedure. Thank you.
I am working on the carotenoid structure. Based on MS-MS and FTIR data it should have the hydroxyl group. To further confirm we dissolved our carotenoid in deuterated methanol (100%) and interestingly, exchange was not observed.
We believed it should be tertiary alcohol present at the end of the carotenoid structure (41 C long) with 10-11 conjugated bonds. Can anyone tell me or has any kind of idea why there is no exchange observed in MS?
Thank you
Dear colleagues, I have larvae of one species of crabronid wasps, which are variously coloured - usually yellow but also orange, reddish, purple. I would like to know how many pigments are responsible for this colouration and which pigments are they. The prey of larvae are aphids and it seems the pigments are carotenoids or aphidines. Could anyone help me with this? I can send frozen or alive larvae of various colours by mail and can offer co-authorship on a paper.
Many thanks and best regards,
Petr
What are the most well-known genes that have been identified & sequenced to produce carotenoid pigments in various organisms (specially in microalgae and yeast)?
Could anyone give some recommendations on what algal strains in UTEX show potentials for high carotenoids or valuable carotenoids production? Ideally Haematococcus, Dunaliella salina and Scenedesmus. Thank you.
Hi all,
I am working with extracts of secondary metabolites of orchid species (roxburghii).
The chromatogram has many peaks that correspond to flavonoids glycosides, glycosides of hydroxycinnamic acids, carotenoids, and chlorophylls. But among them, there are several peaks with unknown spectra. Unfortunately, there are no similar spectra in our library.
Have anyone some suggestions about what kind of compound could be that?

According to the guidance notes the drying process of plant materials should be completed at the stage when there still remains 6 - 10 percent of moisture in the plant. Overdrying under e.g. 6 % seems to decrease the content of carotenoids, ascorbic acid and essential oils - according to the few references I have found. Thus evidence is very limited. Our own tests have shown a slight tendency to decreasing contents of phenolics.
I would be happy to get some new hints, experiences or explanations of this phenomenon!
I have prepared chitosan nano-particles and encapsulated carotenoid pigment within it. I have tried to check its release profile by reported dialysis method (12 kD dialysis membrane ) in PBS of pH 7.4 and 1.2 but I am not getting any satisfying results. Nano-particles are being clumped within dialysis bag. How can I overcome this problem??
I found that alkaloids normally appeared as green spot on tlc plate under long wave UV. Then how about red spot? I'm doing isolation of constituents from plant materials, is the red spot needed to isolate out normally? Does it posses phytochemical properties? Cause I'm thinking is it pigments like carotene or chlorophyll.
Is it possible to have the same content of carotenoid when there is a decrease in the total chlorophyll content? What could be the possible reasons?
Chemical structure, Physical properties, function, antioxidative property, functional properties, effect of carotene on oxidative stability..
I have done pressurized liquid extraction of microalgae using different "green" solvent to extract carotenoids.
The extracts contains also chlorophyll. I want to remove, or at least reduce, the chlorophyll and keep the carotenoid in the extract (so I think activated charcoal can't be used).
I'm focus on the bioactivity of the carotenoids, so acid treatment is maybe not a good issue.
I have two major contraints to taking account : using "green"/GRAS solvent AND using a method who can be scale-up.
What can I do to remove/reduce chlorophyll ?
Thanks in advance
Is there a way to stimulate carotenoid (beta-Carotene) biosynthesis on field ?
Furthermore is there a correlation of the Sweet-potato skin color with any fertilization practices ? (more intense orange skin color)
I have calculated the values of Neoxanthin, violaxanthin, lutein, zeaxanthin, antheraxanthin and beta carotene and Chl a and Chl b by HPLC. How Can I calculate carotenoid content, total chlorophyll content and different ratios among these pigments?
I want to extract carotenoids from alfalfa by soxhlet extraction. which solvent or combinations of solvents is the best choice (3 of them) and what is the appropriate protocol for this extraction.
i'm be grateful if you mention any article.
I'm using Shimadzu HPLC with RID and DAD detector. But the machine is working with single pump so only single mobile phase can be run. So, in what proportion I will make the mobile phase that it will detect carotenoid perfectly?
I have tried to find the pigments absorption coefficients (in m2/mg) but I only find graphs in different publications. I have sent emails to research authors to pass me the data but I have not had any luck.
Would anyone know where to find this data?

The only place that sells trans-antheraxanthin is ChromaDex. But the standard is very dilute and requires high injection volume in HPLC before detection.
Any help in finding a supplier for this carotenoid is appreciated.
I've been thinking about what would be the topic of my thesis, and I feel attracted to develope something related to insects as food. But first, I would like to know what is the perception of it in the scientific community.
Now, I will do a little experiment with carotenes and cricket flour as a test in one of my master's program courses.
Thanks for you attention!
Have a nice day!
Why doesn't the anthocyanins/flavonoids accumulation in petals result in a colored phenotype?
Carotenoids cannot accumulate in the petals because Arabidopsis lack chromoplasts, essential for accumulation or storage of carotenoids. But what is the reason behind flowers not having pigmentation from flavonoids?
I am going to extract fucoxanthin from seaweed. I want to now it is necessary to perform saponification before HPLC in Carotenoid purification? Actually I was wondering if someone tell me what is the important of purification and saponification? Is it related to HPLC peak or something else?
I have extract carotene, now I want to know which type of carotine is this, means it is alpha or beta or gamma. What I should do?
Or any other aspects of pigment ratios that have practical application in food.
Interaction of carotenoids with the superoxide anion radical in relationto their stabilizing effect during cryoconservation of sperm
LI Paramonova, AA Revina, AF Lizunkov - Dolk. Vses. Akad. S.-Kh. Nauk im. VI …, 1989
Carotenoid is light sensitive and is easily disappear from TLC due to exposure to light and air.
I extracted carotenoid sample by mixing equal volumes Chloroplast soln., Cyclohexane and Milli-q. I measured the absorbance at 425nm.
I used other wavelengths as well, such as 495nm,480nm, 470nm, 450nm, 432nm.
But I couldn't find or figure out the equation to calculate its concentration in mg/ml
Similarly, I extracted xanthophyll by using equal volumes of carotenoid solution and 90% methanol. Are you aware of an equation where I can determine the concentration of Xanthophyll? Wavelengths I used = 450nm and 480nm
If you are aware of any papers please refer me to it. I am aware that Goodwin's book is a goldmine but the book is not available to me. Any help is appreciated. thank you.
In 1st step we have extracted plant pigments in 100 %acetone .
Step 2 ... Acetone extract is mixed with petroleum ether in separotory funnel .
Step 3 ......Acetone containing chlorophyll is washed with slow addition of water (here we assuming that carotenoid pigment comes in petloum ether layer )
4th step .....For separating xanthophyll from other carotenoid pigments we added ethanol .....Gradient of dark green to pale green is formed from top to bottom ......Now we assuming that lower portion is xanthophyll and upper carotenoid...
Does this procedure is correct and satisfactory for quantification of xanthophyll ?????
Any new article explain about the mechanism on carotenoid compounds in the rumen?
Thanks!
we are try to comparing total cellular content like chlrophyll ,carotenoid ,anthocyanin, proline ,sugar ,antioxidant enzymes of medicinal plant at different altitude level of Himalayas , know about the plant response to abiotic stresses . Will it show any significant result. what else we can do to make our project more informative ?