The New Complete Book of Food
What Happens When You Cook This Food
Cooking sweetens the potato by converting some of its starches to sugars. Cooking also
changes the potato’s texture. When you bake a sweet potato, the water inside its cells dis-
solves some of the pectins in its cell walls, so the potato gets softer. As it continues to bake,
moisture begins to evaporate from the cells and the potato shrinks. When you boil sweet
potatoes, the initial reaction is just the opposite: at first, the starch granules in the potato
absorb moisture and swell so that the potato looks bigger. If you continue to boil the potato,
however, its starch granules will absorb so much water that they rupture. The water inside
will leak out and the potato, once again, will shrink.How Other Kinds of Processing Affect This Food
Canning. Sweet potatoes canned in water have the same nutrients as cooked fresh sweet
potatoes. Sweet potatoes canned in sugar syrups have more carbohydrates and more calories.Medical Uses and/or Benefits
Lower risk of stroke. Various nutrition studies have attested to the power of adequate potas-
sium to keep blood pressure within safe levels. For example, in the 1990s, data from the
long-running Harvard School of Public Health/Health Professionals Follow-Up Study of male
doctors showed that a diet rich in high-potassium foods such as bananas, oranges, and plantain
may reduce the risk of stroke. In the study, the men who ate the higher number of potassium-
rich foods (an average of nine servings a day) had a risk of stroke 38 percent lower than that of
men who consumed fewer than four servings a day. In 2008, a similar survey at the Queen’s
Medical Center (Honolulu) showed a similar protective effect among men and women using
diuretic drugs (medicines that increase urination and thus the loss of potassium).Adverse Effects Associated with This Food
* * *Food/Drug Interactions
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