Sweet potatoes (Ipomoea batatas) are widely cultivated in tropical and subtropical areas, since it has been introduced from the South America in the early 18th century. The enrichment in starch, crude protein, dietary fibers, minerals, pigments, and polyphenols makes it one of the most important root crops in agricultural production as well as a major raw supply in the food industry nowadays. One of the many varieties of sweet potatoes is the purple fleshed sweet potato which originated in Central and South America. It is believed that explorers introduced them to the Philippines and China in the 15th century, and the potato then made its way to Japan in the 1600’s. The purple sweet potato has distinctive prunosus peel and deep purple flesh with an inviting flavor and mouth feeling. Because of these advantages, the purple sweet potato is served as various dishes, nutritional brewing dry powder, stuffing, sweetmeat etc., in food processing industry, and has become a popular cultivar in Asia.
Purple sweet potatoes get their distinct color from compounds called anthocyanins. This pigment is also found in plants such as cherries, grapes, and strawberries. The content of anthocyanin in purple sweet potato were 19.78 mg/100 g in water extract and 158 mg/100 g in acid-ethanol extract. Purple sweet potatoes have 2.5 times more antioxidants (cyanidins and peonidins) than their orange-fleshed counterparts. These colorful flavonoids have powerful anti-inflammatory and antioxidant properties that have a number of health benefits. Research has shown that sweet potatoes rich in anthocyanins are good for hypertension, diabetes, and boosting cardiovascular health.
Sweet potato is a nutritious vegetable that is rich in starches and can provide energy. It contains complex carbohydrates, dietary fiber, protein, beta carotene (pro vitamin A), vitamin C and vitamin B6. Purple sweet potatoes are rich of beta-carotene and anthocyanin pigments, which act as antioxidants that can help reduce inflammation and boost immune system. Besides, sweet potatoes have a mixture of soluble fiber, which can lower cholesterol and balance glucose, and insoluble fiber, which helps keep the bowels healthy and regular. Sweet potatoes are also a good source of prebiotics like oligosaccharides, which help improve gut’s microbiota and overall gut health.
Purple sweet potato have attractive colours and full of resistant starch which increase their industrial value. It has been promoted as a healthy baby food or food suitable for old folks as they are soft. Purple sweet potatoes can be eaten as mashed potatoes, fries, and soups. They can be used as colorant in making glutinous rice balls, cakes, pie or any Asian cuisine.
