Dr. M. Wasim Haider, Dr. C.M. Ayyub and Dr. Mujahid Ali
Institute of Horticultural Sciences, University of Agriculture Faisalabad
Potato is the topmost vegetable crop cultivated and consumed around the globe including Pakistan. It contains about 45% of the recommended daily amount of vitamin C and provides all essential amino acids. However, the existing cultivars of potato growing under climatic condition of Pakistan considered low in bioactive compounds (antioxidants, carotenoids) that are abundantly found in papa criolla potato most popular in South America. Papa criolla (Solanum phureja) are small yellow colored potatoes (about golf ball size). They are diploids (have two sets of chromosomes) and tuberize under short day conditions with very short or no dormancy. Papa criolla is yellow colored potatoes. Mostly used in the mashed, boiled, fried or baked form and they are delicious.
White-fleshed potatoes (Dutch varieties) cultivated in Pakistan are also low in carotenoid contents having antioxidant activity and beneficial for human health especially eyes. Carotenoids are red, yellow or orange colored highly unsaturated pigments found in mostly plant-based foods. Some vegetables such as carrots, sweet potatoes, and pumpkin have orange colored pigments having more carotenoid contents. Similarly, animals have a very rare amount of carotenoids but some insects such as lobsters and crabs have a pigment known as astaxanthin in their shells. Astaxanthin is a carotenoid pigment, absorbing blue light and appearing red, orange or yellow in color.
So, the carotenoids in papa criolla potatoes, which make the potato yellow-fleshed; lutein and zeaxanthin are available carotenoids which help in the prevention of age-related macular degeneration (AMD). Age-related macular degeneration (AMD) is commonly depicted as human eye condition and leading the cause of vision loss among people having an age of 50 years and older. It causes damage to the macula, a small spot near the center of the retina and the part of the eye needed for sharp, central vision, which lets us see objects that are straight ahead. Lutein and zeaxanthin are important for protecting light-exposed tissues i.e. skin and eyes. These pigments are concentrated in the macula of eyes. This is the area of maximal visual acuity and this spot on the retina is yellow because of the concentration of lutein and zeaxanthin. Both can prevent the eyes from damage by light, particularly the blue rays just above the UV spectrum of the spectrum seem to accelerate AMD more than other rays of the spectrum. Sunglasses protect against both blue/violet and UV light. So, both lutein and zeaxanthin act as sunscreens for the eye but to some extent. So, don’t leave your sunglasses at home. Some other sources of lutein and zeaxanthin are spinach, turnip, eggs, orange juice, corn, and broccoli.
Papa criolla potatoes could really be popular in Pakistani markets among farmers’ community and consumers who are looking for new and health-promoting types of vegetables. It will appeal to consumers who associate color with good nutrition.