Pigments found in food are the natural source of nutrients that benefits the human body. There are seven types of colour pigments including red, orange, yellow, green, purple, black and white, which is also known as “rainbow.”
Red pigment
The red pigments, such as lycopene, capsaicin and betacyanin presence in the fruits and vegetables made the food red in colour. Lycopene might help in reducing the risk of arteriosclerosis and heart diseases, removing the toxicity in the liver, anti-UV light, anti-allergy, prostate and stomach cancer prevention. It improves the male reproductive system [2]. Lycopene could be found in tomato, watermelon, cherry, persimmon and plum.
Besides, one of the natural red colour pigments known as capsaicin found in chilli could promote blood circulation, inhibit or suppress the growth of cancer cells, reduce the risk of heart diseases and increase appetite [5]. While red dragon fruits and beetroot are rich in betacyanin that have antioxidant and anti-inflammation properties, as well as in preventing the growth of cancer cells [6].
Orange or Yellow pigment
Orange and yellow pigments are known as B-carotene and limonin respectively. B-carotene is a kind of antioxidant that reduces the risk of formation of free radicals, which could damage body cells to increase the risk of cancer and ageing. B-carotene helps to improve the vision, delays ageing, strengthen the immune system, reduces the risk of lung, breast and ovarian cancer [2] [3]. Examples of foods including carrot, orange, honeydew, lemon, mango and pineapple. Papaya is another fruit that contains B-carotene as well as papain, which is a kind of enzymes that helps to digest protein into amino acids for better absorption of protein during the digestion process.
Green pigment
Green pigment (chlorophyll) [1] is usually found in vegetables that improve the formation of red blood cells, strengthen the bone and teeth, reduce bloating and constipation as well as preventing colon cancer. Vegetable pigment also protects the skin from UV-light and provides vitamin C to the human body [2]. Sweet potatoes leave, asparagus, cabbage, celery, broccoli, kiwi and water spinach are rich in chlorophyll.
Purple or Black pigment
Anthocyanin is the natural food pigment, which made the food purple in colour that has skin protection properties from the UV-light, prevent the brain from chemicals and toxic damage, improve allergy symptoms and reduce the risk of heart diseases. Anthocyanin also acts as the antioxidant to delay ageing and prevent cancer [3] [4]. Fruits and vegetables such as grapes, purple onion, blueberries, black fungus and black currant contain anthocyanin.
White pigment
White colour vegetables are bitter gourd, garlic and onion [1]. Bitter gourd contains kuguaosides that helps to regulate blood lipids and reduce blood pressure. It also helps in promoting insulin sensitivity to control blood sugar level as well as improves the process of blood glucose oxidation [8]. While allicin is found in garlic that kills bacteria, prevents colon and stomach cancer [7].
References
1. Peringer, A., 2015. The colour of food. Alimentarium. Available online: https://www.alimentarium.org/en/magazine/s cience/colourfood#:~:text=Yellow%2C%20orange%2C%20red%2 0%E2%80%93%20carotenoids%2C%20curcumin%20a nd%20carthamin&text=They%20all%20contain%2 0natural%20colouring,mostly%20in%20fruit%2 0and%20vegetables [Accessed 18 June 2020].
2. Garden-Robinson, J., 2016. What colour is your food? Available online: https://www.ag.ndsu.edu/publications/foodnutrition/what-color-is-your-food#section- 3 [Accessed 18 June 2020].
3. Simon, P. W., Tanumihardjo, S. A., Clevidence, B. A., & Novotny, J. A. 2008. Role of Colour and Pigments in Breeding, Genetics, and Nutritional Improvement of Carrots. ACS Symposium Series, 151–166.
4. Khoo, H.E., Azlan, A., Tang, S.T., Lim, S.M., 2017. Anthocyanidins and anthocyanins: colored pigments as food, pharmaceutical ingredients, and the potential health benefits. Journal of Food and Nutrition Research, 61(1).
5. Saljoughian, M., 2009. Capsaicin: Risk and Benefits. Available online: https://www.uspharmacist.com/article/capsa icin-risks-andbenefits#:~:text=While%20capsaicin%20is%20 reported%20to,produce%20nausea%2C%20vomiti ng%2C%20abdominal%20pain [Accessed 18 June 2020].
6. Khan, M.I., 2016. Plant betalains: Safety, antioxidant activity, clinical efficacy and bioavailability. Comprehensive Review in Food Science and Food Safety, 15(2), 316- 330.
7. Rahman, M.S., 2007. Allicin and Other Functional Active Components in Garlic: Health Benefits and Bioavailability. International Journal of Food Properties, 10(2), 245-268.
8. Krawinkel, M. B. and Keding, G. B. 2006. Bitter Gourd (Momordica charantia): A Dietary Approach to Hyperglycemia. Nutrition Reviews, 64(7), 331–337.
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