Probiotics and digestion. Calcium and bones. Vitamin C and immunity.

When an ingredient experiences both sales and scientific success with a certain claim, it's no surprise the association sticks. This instant consumer connection between ingredient and benefit is a dream for manufacturers and suppliers.

For more than a decade, the carotenoid market has enjoyed such success with eye health, winning over the heartsand eyesof consumers around the globe. But even still, companies are looking past the traditional eye health claims to tap into new markets and demographics.

Across nature, carotenoids deliver the rainbow of yellow, orange and red responsible for autumnal leaves and bright produce. The compounds collect light during photosynthesis, protecting the plants from harmful ultraviolet (UV) rays; however, these organic pigments also offer a host of antioxidant benefits for humans, including prostate, heart, skin and eye health benefits.

These compounds number in the hundreds, but dietary supplements and food and beverages only rely on a handful for their concentrated antioxidantsnamely beta-carotene, lycopene, lutein, zeaxanthin and astaxanthin.

In 2007, BCC Research estimated the global carotenoids market value at US$766 million; 2010 recorded $1.2 billion, an increase of 54 percent. In October 2011, research company Global Industry Analysts said it expects the carotenoid market value to grow to $1.3 billion by 2017.

Overall, beta-carotene leads the pack, with a 22-percent market share of US$261 million, according to BCC. However, lutein follows closely behind at $233 million. BCC's 2018 predictions put lutein at 3.6 percent compounded annual growth rate (CAGR)only second to the up-and-coming beta-apo-8-carotenal, which has a tiny market share, but is experiencing a popularity surge.

Many credit the slow-but-steady market growth to increased consumer education, starting with the traditional eye health channels.

"There has been a recent and significant marketing investment by many well-respected consumer product companies in the industry to promote the benefits," said Alex Fink, health marketing director, Kemin Industries. "Lutein's association with eye health is increasingly becoming common knowledgealong the lines of calcium and bone health."

But now, consumers and manufacturers are opening their eyes and seeing a world of colorstrengthening conventional carotenoid uses and exploring innovative applications.

Charting the Pigments

Because humans cannot create carotenoids, we rely on dietary sources and supplements to deliver the lipid-soluble organic pigments. Divided into two groupscarotenes and oxygen-containing xanthophyllscarotenoids deliver powerful antioxidants and vitamin A precursors. Learn the differences between the most commonly used carotenoids below.

Beta-Carotene Possibly the most well knownand most commoncarotenoid, beta-carotene is provitamin A, meaning the body can convert it to active vitamin A. The photosynthetic pigment is responsible for orange coloring in produce, and is insoluble in watereven more so than the xanthophylls.

Lycopene Found in tomatoes, peppers and grapefruit, this bright red pigment is an antioxidant of the non-provitamin A variety. Lycopene is commonly tied to cancer protection, as research suggests high lycopene levels decrease risk of lung, stomach and prostate cancer.

Lutein Along with zeaxanthin, lutein drives the eye-health market. Lutein helps block blue light from reaching the retina, reducing the oxidative damage that causes age-related macular degeneration (AMD). The yellow xanthophyll appears orange-red at high concentrations, but is not used as a colorant due to its instability.

Astaxanthin Touted for its anti-inflammatory benefits, astaxanthin is a non-provitamin A xanthophyll carotenoid. With only two main sourcesthe microalgae Haematoccous pluvialis and the sea creatures that feed on itastaxanthin reduces oxidative stress by neutralizing unstable singlet oxygen and harmful free radicals.

Zeaxanthin This carotenoid comprises approximately 75 percent of the central macula, while lutein rules the peripheral retina. Though lutein and zeaxanthin have identical chemical formulas, their physical structures differ. Many companies derive zeaxanthin from marigold flowers.