Potato health benefits side effects , nutritional values full guide
Potato ranks as the third most important food crop after wheat and rice. Potatoes yield on average more food energy on a per-hectare and a per-day basis than either cereals or cassava.
In general, potato is perceived only as a source of carbohydrates, but is also an excellent source of essential amino acids. The predominant form of this carbohydrate is starch.
Types of potato :
Several yellow, red, and purple fleshed types with high phytochemical content have recently been introduced into the market. The purple potato has purple skin and flesh, which becomes blue once cooked. A mutation in the varieties’ P locus causes production of the antioxidant anthocyanin . Total phenolics in
A small but significant portion of this starch is resistant to digestion by enzymes in the stomach and small intestine, and so reaches the large intestine essentially intact.
potato benefits -effects :
This resistant starch is considered to have similar physiological effects and health benefits as dietary fiber: it provides bulk, offers protecttion against colon cancer, improves glucose tolerance and insulin sensitivity, lowers plasma cholesterol and triglyceride concentrations, increases satiety, and possibly even reduces fat storage.
The amount of resistant starch in potatoes depends much on preparation methods. Cooking and then cooling potatoes significantly increases resistant starch. For example, cooked potato starch contains about 7% resistant starch, which increases to about 13% upon cooling .
Due to carbohydrate content, potatoes are considered to make a person obese if used in excess i.e. more than RDA of carbohydrates and fats. Recent research by the University of California, Davis and the National Center for Food Safety and Technology, Illinois Institute of Technology demonstrates that people can include potatoes in their diet and still lose weight .
potatoes -(GI) :
Potatoes are also often broadly classified as high on the glycemic index (GI) and so are often excluded from the diets of individuals trying to follow a low-GI diet. In fact, the GI of potatoes can vary considerably depending on type (such as red, russet or white), origin (where it was grown), preparation methods (i.e., cooking method, whether it is eaten hot or cold, whether it is mashed or cubed or consumed whole, etc.), and with what it is consumed (i.e., the addition of various high-fat or high-protein toppings) .
Potato health benefits :
- Potato contains a small amount of protein (less than 6%), but the biological value of potato protein is the best among vegetable sources and comparable to cow’s milk. Human feeding trials suggested that potato proteins are of a very high quality, possibly because they are rich in essential amino acids, such as lysine, and other metabolites, which may enhance protein utilization.
- The lysine content of potato complements cereal-based diets, which are deficient in this amino acid. In addition to high quality proteins, potato tubers accumulate significant amounts of vitamins and minerals, as well as an assortment of phytochemicals including phenolics, phytoalexins, and protease inhibitors.
- Chlorogenic acid constitutes up to 90% of the potato tuber natural phenols. Others found in potatoes are 4-O-caffeoylquinic acid (crypto-chlorogenic acid), 5-O-caffeoylquinic (neo-chlorogenic acid), 3,4-dicaffeoylquinic and 3,5-dicaffeoylquinic acids .
- A medium-size 150 g potato with the skin provides 27 mg of vitamin C (45% of the daily allowance), 620 mg of potassium (18% of daily allowance), 0.2 mg vitamin B6 (10% of daily allowance) and trace amounts of thiamin, riboflavin, folate, niacin, magnesium, phosphorus, iron, and zinc.
- The fiber content of a potato with skin (2 g) is equivalent to that of many whole grain breads, pastas, and cereals. Potato contributes a small but significant amount of phytochemicals.
- potato tubers range in concentration from 0.5 to 1.7 g/kg . Al-Saikhan et al. reported significant differences in total phenolics among cultivars, with flesh color having no significant effect on total phenolics. Nearly 50% of the total phenolic compounds in potato are located in the peel and adjoining tissue, but decrease toward the center of the tuber , with chlorogenic acid representing about 90 percent of the total polyphenolic content .
- Potato tubers contain a moderate amount of vitamin C, in the range of about 10 to 104 mg/kg, depending on the cultivar and the growing season, but it declined rapidly (30 to 50 percent) during storage and cooking.
- Other antioxidants found in potato include 0.5 to 2.8 mg/kg α-tocopherol, 0.13 to 0.6 mg/kg lutein, and 1 mg/kg β-carotene .
- estimated the total antioxidant capacity of potato to be in the medium range among 22 commonly consumed vegetables. Potato also contributes a small amount of selenium (0.01 mg/kg) and folate (0.35 mg/kg) to the human diet.