Edible colors are natural pigments found in tissue of plants. These are the chemical compounds produced by several biochemical pathways and give colors to the food. These colors change according to the growth stage of the plant parts, and vegetables are comprised of pigments, anthocyanins, betalains, carotenoids, and chlorophyll. These pigments play important ecological and metabolic functions in the plants and are more frequently exploited as the source of nutraceuticals to address a number of human ailments. These pigments have been implicated in regimes to maintain human health, to protect against chronic disease(s), or to restore wellness by repairing tissues after disease has been established. A wide range of bioassays and tests have been forwarded to establish the biological efficacy of natural pigments in human health intervention. Different color fruits and vegetables contain unique components that are essential to our health. Therefore, by eating fruits and vegetables of a variety of colors, one can get the best all-around health benefits.
Anthocyanins
Anthocyanins are natural pigments belonging to the flavonoid family. They are responsible for the blue, purple, red and orange colors of many fruits and vegetables. Anthocyanins are capable of acting on different cells involved in the development of atherosclerosis, one of the leading causes of cardiovascular dysfunction. Anthocyanins and the aglycone cyanidin were found to inhibit cyclooxygenase enzymes, which can be one marker for the initiation stage of carcinogenesis. Recently, both the anthocyanins and cyanidin aglycone from tart cherries reduced cell growth of human colon cancer cell lines. On one hand they can interfere with glucose absorption, and on the other hand they may have a protective effect on pancreatic cells. The most extensively documented phytomedicinal role of anthocyanin pigments is in improving eyesight, including night vision. Anthocyanins exert significant antimicrobial properties, and (in association with other flavonoids) have demonstrated quite effective inhibition of aflatoxin biosynthesis.
Betalains
Betalains have been widely used as natural colorants for many centuries, but their attractiveness for use as colorants of foods (or drugs and cosmetics) has increased recently due to their reportedly high anti-oxidative, free radical scavenging activities and concerns about the use of various synthetic alternatives, e.g. beet root.
Carotenoids
Carotenoids are the second most abundant pigments in nature and consist of more than 700 members. Carotenoids play an important role in plant reproduction, through their role in attracting pollinators and in seed dispersal, and are essential components of humans’ diets. Beta-carotene provides protection to vision and eye function, and against macular degeneration and cataracts. Carotenoids are credited with biological promotion of immune system response. It is associated with inhibition of several types of cancers including cervical, esophageal, pancreatic, lung, prostate, colorectal and stomach.
Chlorophylls
Chlorophyll is the most important plant pigment and a “real life force” that nature uses to explode plants into greenery. Chlorophylls are typically consumed in much higher doses in a diet that incorporates green and leafy vegetables. The anti-mutagenic properties of chlorophylls have been demonstrated in various assays, and clearly, intake of chlorophyll has potential to act as a chemopreventive compound in humans.
Orange Color Carrot
The orange color of carrot is due to carotenoids. The beta-carotene (pro-vitamin A) is a precursor of vitamin A in the human body. Four carotenoids viz., beta-carotene, alpha-carotene, gamma-carotene and beta-cryptoxanthin have vitamin A activity in humans, which means they can be converted into the visual pigment retinol and are classified as essential nutrients. More than four million children, most from developing countries, exhibit clinical symptoms of severe vitamin A deficiency, including poor immunity, loss of vision in low light conditions (night blindness) and in extreme cases, an irreversible form of blindness called xerophthalmia and maintenance of healthy epithelial cell differentiation, normal reproductive performance, and visual function. The dark orange varieties have the B-carotene concentration up to 130-500ppm.
Yellow Color Carrot
The yellow color of roots due to xanthophylls (lutein and zeaxanthin) is collectively referred to as a macular pigment (MP). It is found in the macular region of the eye in humans and may have importance in eye health and protection from age-related macular degeneration. Lutein is an important pigment in yellow carrots.
Red Color Carrot
Red carrots contain lycopene in addition to alpha- and beta-carotene. The utility of red carrot as a functional food depends on the bioavailability of its constituent of carotenoids. Lycopene is the carotenoid primarily responsible for the color of red carrots. It is an excellent dietary antioxidant and plays a role in reducing the risk of a number of cancers and coronary heart diseases. . . The red carrots are commonly consumed as a salad and gajar halwa during winter months (November-January) coming from winter season carrots in northern India.
Purple Color Carrot
A group of polyphenolic pigments called anthocyanins are responsible for the color of purple carrots. Current cultivars of purple varieties include solid purple carrots, often referred to as black carrots. The primary anthocyanins found in purple carrots are derivatives of cyanidin, but pelargondin and peonidin glycosides have also been identified. Dietary anthocyanins may play a role in health promotion and protection from cardiovascular disease and anti-cancer activity and beneficial effects on diabetes.
Multi Color Carrots
Colorful specialty carrots have been “re-discovered” by modern plant breeders interested in improving and diversifying the nutrition of the food supply. Carrots have gained popularity in recent years, due to increased awareness of its nutritional value, especially eye-appealing external and internal root color. Orange carrots’ color is considered “good for the eyes” due to the high amount of carotenoids especially beta-carotene.
Dr. Pritam Kalia is a faculty member at the PUSA Institute in New Delhi. Dr. Kalia developed the popular Pusa Asita black carrot.
