Carotenoids: Types, Food Sources, Absorption & Human Research

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Carotenoids are a large family of naturally occurring pigments produced by plants, algae, and certain microorganisms. They contribute many of the yellow, orange, and red colors found in fruits and vegetables, although carotenoids can also be present in dark green plant tissues where chlorophyll masks their color.

Well-known dietary carotenoids include beta-carotene, alpha-carotene, lycopene, lutein, zeaxanthin, and beta-cryptoxanthin.

But these compounds do not all perform the same nutritional role. Beta-carotene, alpha-carotene, and beta-cryptoxanthin can contribute to vitamin A nutrition, while lycopene, lutein, and zeaxanthin cannot be converted into vitamin A.

Carotenoids also differ in food sources, absorption, tissue distribution, metabolism, and the types of human research in which they have been studied.

For FruitFast, carotenoid chemistry is relevant to fruits such as watermelon, mango, apricot, peach, citrus, and other colorful fruits. The presence of carotenoids in a source fruit does not establish a particular carotenoid concentration in a finished FruitFast concentrate without product-specific analysis.

The Short Answer

Carotenoids are fat-soluble plant pigments divided broadly into carotenes and xanthophylls.

Carotenes include beta-carotene, alpha-carotene, and lycopene.

Xanthophylls are oxygen-containing carotenoids such as lutein, zeaxanthin, beta-cryptoxanthin, violaxanthin, and neoxanthin.

Some carotenoids—especially beta-carotene, alpha-carotene, and beta-cryptoxanthin—have provitamin A activity, meaning the body can convert them into vitamin A.

Others, including lycopene, lutein, and zeaxanthin, do not become vitamin A but are studied for other biological roles.

Carotenoid absorption depends strongly on the food matrix, processing, digestion, and dietary fat. A carotenoid measured in a raw fruit should not automatically be assigned to a finished juice or concentrate.

What Are Carotenoids?

Carotenoids are lipid-soluble pigments built from isoprenoid structures.

Hundreds of carotenoids have been identified in nature, although only a much smaller subset occurs commonly in the human diet and circulation.

In plants, carotenoids contribute to:

• light harvesting;
• photoprotection;
• pigmentation;
• photosynthetic regulation;
• precursors for signaling molecules; and
• color signals involved in fruit and flower biology.

Those plant functions should not automatically be interpreted as effects a carotenoid will produce after humans consume it.

Why Are Fruits & Vegetables Different Colors?

Carotenoids are responsible for many yellow, orange, and red colors, but food color usually reflects several pigment systems at once.

Examples include:

• beta-carotene — yellow-orange;
• alpha-carotene — yellow-orange;
• lycopene — red;
• lutein — yellow;
• zeaxanthin — yellow-orange; and
• beta-cryptoxanthin — orange-red.

However, visible color cannot determine carotenoid concentration.

A dark green spinach leaf can contain substantial lutein whose yellow color is masked by chlorophyll, while a red fruit may contain anthocyanins, lycopene, betalains, or combinations of different pigments.

What Are the Major Dietary Carotenoids?

Carotenes vs. Xanthophylls: What Is the Difference?

Dietary carotenoids are commonly separated into two structural groups.

All xanthophylls are carotenoids, but not all carotenoids are xanthophylls.

Explore this branch in detail in our Xanthophylls guide.

Which Carotenoids Can Become Vitamin A?

Only certain carotenoids have meaningful provitamin A activity.

The major dietary examples are:

• beta-carotene;
• alpha-carotene; and
• beta-cryptoxanthin.

The body can enzymatically cleave these molecules and use their products in vitamin A metabolism.

By contrast:

• lycopene does not become vitamin A;
• lutein does not become vitamin A; and
• zeaxanthin does not become vitamin A.

This is why the statements “carotenoids are vitamin A” and “all orange pigments become vitamin A” are incorrect.

Beta-Carotene & Vitamin A

Beta-carotene is the best-known provitamin A carotenoid.

After intestinal absorption, beta-carotene can be cleaved by enzymes including beta-carotene oxygenase 1, commonly called BCO1 or BCMO1, to contribute to retinoid metabolism.

The efficiency of conversion is not identical in everyone.

Conversion can be influenced by:

• vitamin A status;
• beta-carotene dose;
• food matrix;
• fat intake;
• digestive function;
• genetic variation; and
• other dietary factors.

This regulated conversion is one reason food beta-carotene should not simply be equated milligram-for-milligram with preformed vitamin A.

Beta-Carotene vs. Vitamin A

Beta-carotene is not itself preformed vitamin A.

Preformed vitamin A includes retinol and retinyl esters found mainly in animal foods and supplements.

Beta-carotene is a precursor that the body can convert into vitamin A compounds.

This distinction matters when interpreting nutrition labels, dietary recommendations, supplement doses, and safety research.

What Is Lycopene?

Lycopene is a red hydrocarbon carotenoid.

Important dietary sources include:

• tomatoes and tomato products;
• red watermelon;
• pink and red grapefruit;
• guava;
• papaya; and
• certain other red fruits.

Lycopene does not have provitamin A activity.

It is extensively studied in relation to antioxidant chemistry, food processing, blood concentrations, cardiovascular biomarkers, prostate research, and other human-health questions.

Those areas of research should not be simplified into a claim that lycopene-containing foods prevent cardiovascular disease or cancer.

What Foods Contain Carotenoids?

Carotenoids occur in a wide variety of fruits and vegetables.

Examples include:

• carrots — beta-carotene and alpha-carotene;
• sweet potatoes — especially beta-carotene;
• pumpkin and squash — beta-carotene, alpha-carotene, lutein, and other carotenoids;
• tomatoes — especially lycopene;
• red watermelon — especially lycopene;
• dark leafy greens — especially lutein and beta-carotene;
• corn — lutein and zeaxanthin;
• orange peppers — zeaxanthin and beta-cryptoxanthin;
• mandarins and oranges — beta-cryptoxanthin and other carotenoids;
• mangoes — mixtures of beta-carotene and xanthophylls;
• apricots and peaches — mixtures including beta-carotene and beta-cryptoxanthin; and
• papaya and persimmon — multiple carotenoids including beta-cryptoxanthin.

The term “high in carotenoids” needs context because foods differ in the particular carotenoids they contain.

Which Foods Are Highest in Carotenoids?

There is no single meaningful ranking of “total carotenoids” that answers every nutritional question.

A food may be:

• high in beta-carotene;
• high in lycopene;
• high in lutein;
• high in beta-cryptoxanthin; or
• moderate in several carotenoids at once.

Laboratories can also use different extraction, saponification, chromatographic, and calculation methods.

For useful comparisons, it is usually better to ask which specific carotenoid a food contains.

Carotenoids in FruitFast-Relevant Fruits

Several fruits used in FruitFast products occur in the carotenoid literature.

The descriptions below refer to the source fruits, not measured specifications for FruitFast finished products.

Are Carotenoids Antioxidants?

Many carotenoids participate in antioxidant and redox chemistry in laboratory and biological systems.

Some can quench singlet oxygen or interact with reactive chemical species under particular conditions.

But “carotenoids are antioxidants” should not be expanded into the claim that every carotenoid simply circulates through the body and neutralizes free radicals.

Carotenoid behavior depends on:

• specific carotenoid;
• concentration;
• oxygen tension;
• membrane environment;
• tissue distribution;
• metabolism;
• other antioxidants and nutrients; and
• physiological context.

Human clinical outcomes therefore cannot be predicted from a chemical antioxidant assay alone.

See our Antioxidants, Free Radicals & Oxidative Stress guide.

How Are Carotenoids Absorbed?

Carotenoids are fat-soluble compounds.

Before absorption, they must first be released from the food matrix during digestion and incorporated into mixed micelles containing dietary lipids, bile components, and other molecules.

After intestinal uptake, carotenoids are packaged into lipoprotein-containing particles and transported through circulation.

Bioavailability therefore depends on more than the amount printed in a food-composition table.

Does Dietary Fat Improve Carotenoid Absorption?

Yes, dietary fat can enhance carotenoid absorption.

A systematic review and meta-analysis examining both laboratory digestion studies and randomized human trials found that co-consuming carotenoid-containing foods with dietary fat generally increased carotenoid bioavailability.

The relationship varies according to:

• amount of fat;
• type of fatty acids;
• specific carotenoid;
• food matrix;
• meal composition; and
• individual physiology.

The evidence should not be simplified into one universal amount of fat required for every carotenoid-containing food.

A Human Salad & Avocado Example

A controlled crossover study provides a useful illustration.

Researchers studied carotenoid absorption from salsa and salad meals with or without avocado or avocado oil.

Adding avocado substantially increased post-meal absorption of carotenoids including:

• lycopene;
• beta-carotene;
• alpha-carotene; and
• lutein.

The study demonstrates that the surrounding meal can materially change carotenoid exposure.

It does not mean avocado is required every time a carotenoid-containing food is eaten.

How Processing Affects Carotenoids

Processing can both reduce carotenoid concentration and increase carotenoid bioaccessibility.

Those statements are not contradictory.

Processing can:

• break plant cell walls and release carotenoids from the food matrix;
• increase extractability;
• increase micellar incorporation during digestion;
• cause trans-to-cis isomerization;
• oxidize or degrade carotenoids;
• remove pigment-containing solids through clarification or filtration;
• alter carotenoid esters; and
• change the final food matrix.

A 2023 comprehensive review emphasizes that higher measured carotenoid levels or bioaccessibility can sometimes occur after processing because carotenoids become easier to extract from disrupted tissues, even though degradation can also occur.

Why Processed Tomato Can Deliver Lycopene Differently

Lycopene is a classic example of food matrix effects.

Fresh tomato tissue contains predominantly all-trans lycopene.

Heating and mechanical processing can:

• disrupt tomato cell structures;
• release lycopene from the food matrix;
• produce some cis-isomerization; and
• alter its accessibility during digestion.

Human studies have found greater lycopene uptake from certain heat-processed tomato preparations than from unprocessed tomato juice.

This does not mean more processing always produces more lycopene. Heat, oxygen, light, and prolonged storage can also degrade carotenoids.

Does Juice Concentrate Contain Carotenoids?

A juice concentrate made from carotenoid-containing fruit can contain carotenoids originating from the starting fruit.

However, the final carotenoid profile depends on:

• fruit species and cultivar;
• fruit maturity;
• flesh and skin pigmentation;
• pressing and extraction;
• clarification and filtration;
• temperature;
• oxygen;
• light exposure;
• concentration method;
• storage time and conditions; and
• analytical method.

Without appropriate finished-product analysis, FruitFast should not assign specific beta-carotene, lycopene, lutein, zeaxanthin, beta-cryptoxanthin, or total-carotenoid values to a finished juice concentrate based solely on published raw-fruit data.

Brix does not measure carotenoids.

Does Concentrating Juice Automatically Concentrate Carotenoids?

Not in a way that can be calculated reliably from Brix alone.

Removing water can increase the concentration of compounds that remain in solution or suspension, but carotenoids are lipophilic pigments whose behavior can also be influenced by:

• insoluble fruit material;
• clarification;
• filtration;
• oxidation;
• isomerization;
• heat;
• light;
• precipitation; and
• storage.

The finished product must therefore be tested if a quantitative carotenoid claim is desired.

Carotenoid Benefits: What Has Human Research Actually Shown?

The term “carotenoid benefits” is too broad to describe one clinical effect.

Human research includes very different questions involving:

• provitamin A nutrition;
• lutein and zeaxanthin in retinal tissue;
• beta-carotene supplements;
• lycopene-rich tomato foods;
• circulating carotenoid biomarkers;
• dietary patterns rich in fruits and vegetables; and
• disease endpoints.

Those lines of evidence should not be collapsed into one claim that “carotenoids prevent disease.”

Provitamin A Is an Established Nutritional Function

The strongest established nutritional role within the carotenoid family is the ability of specific compounds to contribute to vitamin A nutrition.

Beta-carotene, alpha-carotene, and beta-cryptoxanthin can be converted into vitamin A-related compounds.

Lycopene, lutein, and zeaxanthin cannot.

This is an established nutritional function—not merely an antioxidant theory.

Lutein & Zeaxanthin Research

Lutein and zeaxanthin are selectively accumulated in the human retina and, together with meso-zeaxanthin, form macular pigment.

Human supplementation studies show that lutein and zeaxanthin can increase macular pigment optical density under certain conditions.

The AREDS2 clinical program also studied lutein and zeaxanthin as part of a specific multinutrient formulation in people already at elevated risk for progression of age-related macular degeneration.

These results apply to the populations and formulations studied and should not become a claim that every carotenoid-containing fruit prevents eye disease.

See our Xanthophylls guide for the detailed evidence.

A Critical Beta-Carotene Supplement Finding

Carotenoid research also provides an important example of why food associations and isolated supplements should not be treated as equivalent.

Observational research had associated diets rich in carotenoid-containing fruits and vegetables with favorable health patterns.

But large randomized trials of high-dose beta-carotene supplements produced very different results in people at high risk for lung cancer.

This is one of the clearest demonstrations in nutrition science that:

food association ≠ isolated compound ≠ high-dose supplement ≠ clinical outcome.

What About Lycopene Research?

Lycopene has been investigated extensively in observational studies and human interventions involving:

• tomato foods;
• tomato extracts;
• purified lycopene;
• blood-pressure and vascular biomarkers;
• oxidative measurements;
• prostate-related outcomes; and
• other health questions.

Results vary according to whether the intervention is a whole tomato food, concentrated tomato product, isolated lycopene, or mixed carotenoid preparation.

A result from tomato paste should not automatically be attributed to lycopene alone, and a result from purified lycopene should not become a claim about watermelon juice.

Carotenoid-Rich Foods vs. Carotenoid Supplements

A carotenoid-rich fruit or vegetable is chemically very different from a purified supplement.

A food may provide:

• multiple carotenoids;
• vitamin C;
• polyphenols;
• minerals;
• organic acids;
• natural carbohydrates;
• fiber when the whole food is eaten; and
• many additional constituents.

A supplement may provide tens of milligrams of one isolated carotenoid.

Those exposures should not be treated as nutritionally or clinically interchangeable.

How Are Carotenoids Measured?

Carotenoids generally require compound-specific analytical separation.

Methods can include:

• high-performance liquid chromatography, or HPLC;
• ultra-performance liquid chromatography, or UPLC;
• UV-visible or photodiode-array detection;
• liquid chromatography coupled with mass spectrometry;
• tandem mass spectrometry; and
• specialized methods for carotenoid isomers and esters.

Laboratories may measure:

• individual carotenoids;
• all-trans and cis isomers;
• free versus esterified xanthophylls;
• total carotenes;
• total xanthophylls; or
• total carotenoids.

Those measurements are not automatically interchangeable.

Does “Total Carotenoids” Tell You How Much Beta-Carotene or Lycopene Is Present?

No.

A total-carotenoid value combines multiple pigments.

It does not identify how much of the total is:

• beta-carotene;
• alpha-carotene;
• lycopene;
• lutein;
• zeaxanthin;
• beta-cryptoxanthin; or
• another carotenoid.

Likewise:

• Brix is not total carotenoids;
• fruit color is not total carotenoids;
• total antioxidant capacity is not total carotenoids; and
• total carotenoids do not establish an individual carotenoid concentration.

Are Carotenoids Essential Nutrients?

Carotenoids as a whole are not classified as one essential nutrient.

However, provitamin A carotenoids can contribute to meeting the body's requirement for vitamin A.

Lutein, zeaxanthin, and lycopene do not currently have established Recommended Dietary Allowances.

This is another reason all carotenoids should not be grouped under one universal dietary recommendation.

Are Carotenoids Safe?

Carotenoids occur naturally in commonly consumed fruits and vegetables.

High supplemental exposures should be considered separately from ordinary food intake.

Large intakes of carotenoid-rich foods can sometimes cause temporary yellow-orange skin coloration known as carotenodermia or carotenemia. This differs from vitamin A toxicity and usually resolves when carotenoid intake decreases.

The most important supplement-specific safety issue involves high-dose beta-carotene supplementation in people who smoke, formerly smoked, or have substantial asbestos exposure.

Those populations should not assume that a concentrated beta-carotene supplement is beneficial simply because beta-carotene also occurs naturally in vegetables and fruit.

Frequently Asked Questions About Carotenoids

How to Evaluate Carotenoid Research

When reading a carotenoid study, first determine which compound and preparation researchers actually tested.

A study might involve:

• beta-carotene;
• alpha-carotene;
• lycopene;
• lutein;
• zeaxanthin;
• beta-cryptoxanthin;
• a mixed-carotenoid supplement;
• a multinutrient formulation;
• a whole fruit or vegetable;
• a juice or processed food; or
• a laboratory or animal model.

Those interventions are not interchangeable.

It is also useful to ask:

• Compound identity — Which carotenoid was measured?
• Provitamin A activity — Can the compound be converted into vitamin A?
• Dose — Ordinary food exposure or pharmacological supplementation?
• Food matrix — Raw vegetable, cooked food, juice, concentrate, oil, or capsule?
• Dietary fat — What was consumed with the carotenoid?
• Processing — Did heating, crushing, or homogenization alter bioaccessibility?
• Population — Healthy participants, people with nutrient deficiency, smokers, or people with a diagnosed condition?
• Study duration — One meal or several years?
• Outcome — Blood carotenoid, vitamin A status, macular pigment, biomarker, symptoms, or clinical event?
• Other ingredients — Was the carotenoid tested alone or with other nutrients?

A laboratory antioxidant result, higher plasma carotenoid concentration, improved vitamin A status, a change in retinal pigment, and prevention of disease are very different levels of evidence.

FruitFast Fruits Connected to Carotenoid Chemistry

FruitFast offers concentrates made from several fruits that occur in the broader carotenoid literature, including watermelon, mango, apricot, peach, citrus-related fruits, and others.

These links are provided because the source fruits are chemically relevant—not as claims that finished FruitFast products contain a particular measured beta-carotene, lycopene, lutein, zeaxanthin, beta-cryptoxanthin, or total-carotenoid concentration.

Explore Fruit Juice Concentrates →
Finished-product carotenoid values should be established with appropriate product-specific analysis rather than inferred from raw-fruit composition, color, processing assumptions, or Brix.

Continue Exploring Carotenoids & Fruit Compounds

Xanthophylls →
Explore lutein, zeaxanthin, beta-cryptoxanthin, and other oxygen-containing carotenoids.

Vitamin C →
Compare carotenoids with an essential water-soluble vitamin commonly found alongside them in fruits and vegetables.

Phytonutrients & Phytochemicals →
Learn how carotenoids fit within the larger world of naturally occurring plant compounds.

Antioxidants, Free Radicals & Oxidative Stress →
Understand why chemical antioxidant activity should not automatically be interpreted as a demonstrated human health outcome.

Fruit Compound Library →
Browse FruitFast guides to carotenoids, flavonoids, tannins, phenolic acids, pigments, nutrients, and other compounds.

Health Information & Fruit Nutrition Research →
Explore the broader FruitFast research and nutrition library.

Scientific References & Sources

The publications below are provided so readers can examine carotenoid classification, food sources, vitamin A activity, absorption, processing, retinal research, beta-carotene supplementation, and food-matrix effects. Findings involving one carotenoid, supplement, food, biomarker, or patient population should not automatically be generalized to another preparation or FruitFast product.

1. Saini RK, Nile SH, Park SW. Carotenoids from fruits and vegetables: Chemistry, analysis, occurrence, bioavailability and biological activities. Food Research International. 2015;76(Pt 3):735-750. doi:10.1016/j.foodres.2015.07.047. PMID: 28455059.

2. National Institutes of Health, Office of Dietary Supplements. Vitamin A and Carotenoids: Fact Sheet for Health Professionals. U.S. Department of Health and Human Services.

3. Meléndez-Martínez AJ, Esquivel P, Rodriguez-Amaya DB. Comprehensive review on carotenoid composition: Transformations during processing and storage of foods. Food Research International. 2023;169:112773. doi:10.1016/j.foodres.2023.112773. PMID: 37254377.

4. Yao Y, Tan P, Kim JE. Effects of dietary fats on the bioaccessibility and bioavailability of carotenoids: a systematic review and meta-analysis of in vitro studies and randomized controlled trials. Nutrition Reviews. 2022;80(4):741-761. doi:10.1093/nutrit/nuab098. PMID: 34897461.

5. Unlu NZ, Bohn T, Clinton SK, Schwartz SJ. Carotenoid absorption from salad and salsa by humans is enhanced by the addition of avocado or avocado oil. Journal of Nutrition. 2005;135(3):431-436. doi:10.1093/jn/135.3.431. PMID: 15735074.

6. Wilson LM, Tharmarajah S, Jia Y, Semba RD, Schaumberg DA, Robinson KA. The Effect of Lutein/Zeaxanthin Intake on Human Macular Pigment Optical Density: A Systematic Review and Meta-Analysis. Advances in Nutrition. 2021;12(6):2244-2254. doi:10.1093/advances/nmab071. PMID: 34157098.

7. Age-Related Eye Disease Study 2 Research Group. Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial. JAMA. 2013;309(19):2005-2015. doi:10.1001/jama.2013.4997. PMID: 23644932.

8. Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group. The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. New England Journal of Medicine. 1994;330(15):1029-1035. doi:10.1056/NEJM199404143301501. PMID: 8127329.

9. Omenn GS, Goodman GE, Thornquist MD, et al. Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease. New England Journal of Medicine. 1996;334(18):1150-1155. doi:10.1056/NEJM199605023341802. PMID: 8602180.

10. Unlu NZ, Bohn T, Francis DM, Nagaraja HN, Clinton SK, Schwartz SJ. Lycopene from heat-induced cis-isomer-rich tomato sauce is more bioavailable than from all-trans-rich tomato sauce in human subjects. British Journal of Nutrition. 2007;98(1):140-146. doi:10.1017/S0007114507685201. PMID: 17391568.

11. Aschoff JK, Rolke CL, Breusing N, et al. Bioavailability of β-cryptoxanthin is greater from pasteurized orange juice than from fresh oranges—a randomized cross-over study. Molecular Nutrition & Food Research. 2015;59(10):1896-1904. doi:10.1002/mnfr.201500327. PMID: 26114420.

12. Stahl W, Sies H. Uptake of lycopene and its geometrical isomers is greater from heat-processed than from unprocessed tomato juice in humans. Journal of Nutrition. 1992;122(11):2161-2166. doi:10.1093/jn/122.11.2161. PMID: 1432255.

About This Guide

This page is provided for general educational purposes. Research involving carotenoids, beta-carotene, alpha-carotene, lycopene, lutein, zeaxanthin, beta-cryptoxanthin, whole foods, juices, supplements, biomarkers, laboratory models, or specific patient populations should not be assumed to establish the same effect for another food, product, or individual.

References to carotenoids found in watermelon, mango, apricot, peach, citrus, or other fruits describe compounds reported in the fruit or preparation actually studied and should not be interpreted as quantitative claims about a FruitFast finished product unless that finished product has appropriate supporting analytical data.

Human research involving purified or high-dose carotenoid supplements should not be interpreted as evidence that a fruit food or FruitFast concentrate delivers the same dose, exposure, or clinical outcome.

Descriptions of provitamin A activity, retinal accumulation, antioxidant chemistry, processing-related bioavailability, or other biological properties should not be interpreted as claims that a FruitFast product prevents or treats eye disease, vitamin A deficiency, cancer, cardiovascular disease, or another medical condition.

This information is not intended to diagnose, treat, cure, or prevent any disease and should not be interpreted as medical advice.