Sweet potato, A Wonder Crop
Sweet potato (Ipomoea batatas (L.) Lam.), known as a Shakhar khanda, is well known long-term species in a warm and hot climate zone and an annual plant (spring) in temperate zone. It has moist and delicate tubers with sweetish taste, and aromatic smell. It also has a high nutritional value – about 50% higher than potato. So, it plays an important role in the nutrition of world’s population.
Tubers are considered as main usable part of the sweet potato. Tubers are characterized by a high unit mass (1−5 kg); with diverse shapes like spherical, oval, fusiform; skin and flesh are white, cream, yellow, orange, red, claret and even purple, depending on a cultivar. The main nutritional material in sweet potato’s tubers is carbohydrates (starches and simple sugars), protein, fat and fat-soluble vitamins. Moreover, yellow flesh cultivars also contain significant amounts of carotenes. Maloney et al. 2012 pointed out that valuable proteins can be extracted from the peel during processing of sweet potatoes.
Sweet potato roots are bulky and perishable unless cured which limits the distance over which sweet potato can be transported economically. Katan and De Roos, 2004 mentioned that It was established that in cases where countries are capable of generating surplus, it tends to be relatively localized and this leads to a lack of market integration and limits market size . Moreover, production is highly seasonal in most countries leading to marked difference in the quantity quality and quantity of roots in markets and associated price fluctuation. Moreover, in Africa, there is commercial processing into chips or flour, which could be stored for year round consumption for use such as in bread and cakes, or processing into fermented and dried products like fufu.
Sweet potato consumption has been thought to decline as incomes rise – a change which is linked with urbanization, partly because it is considered as a “poor man’s food” . A approach to achieve the goal of sweet potato product development would be to increase the nutritional content of the highly consumed crop.
Sweet potato and its nutritional importance
Table 1. Sweet potato chemical composition (per Serving of one medium 5 inch long sweet potato; 130 g).
|Calories from fat||g||0.39|
|Vitamin C||mg||3.1 (excellent source)|
|Vitamin A||IU||18443 (excellent source)|
Sweet potato’s tubers has anti-oxidant, anti-diabetic and anti-proliferative properties due to the presence of valuable minerals and nutritionl components . Moreover, Sweet potato tubers, which are steady item with in the Americans’ diet, appear to be very beneficial in the diet of diabetics consumers with an insulin resistance, because they are considered to have a low glycemic index according to Ludvik et al. (2004). Knowledge of the glycemic index (GI) diet for diabetes may help to predict their daily dietary intake in order to control a blood glucose level.
GI of a pure glucose, which is used as the standard for other products, is 100, while the GI of sweet potato’s tubers, depending on whether they are boiled, baked or prepared in a microwave, is: 63 ± 3.6; 64 ± 4.3 or 66 ± 5.7, respectively. It encourages using them in the diet of diabetics (Allen et al. 2012 ; Maloney, 2012). Recently, Poland is considered in increasing interest in the cultivation of these vegetables, as raw material with excellent nutritional values, mainly for the food and pharmaceutical industries. However, the knowledge about sweet potato is not sufficient, especially on their nutritional values.
The sweet potato is rich in an antioxidant called beta carotene, which is very effective at raising blood levels of vitamin A. Sweet potatoes are nutritious, high in fiber, very filling, and delicious. They can be eaten boiled, baked, steamed, or fried. Sweet potatoes are usually orange in color but also found in other colors, such as white, red, pink, violet, yellow, and purple. Sweet potatoes are only distantly related to regular potatoes.