The Food Value of Tapioca

The starch found in pearl tapioca and tapioca puddings comes from the root of a plant native to Brazil. European sailors brought tapioca, also known as manioc or cassava, to Africa and other tropical regions as early as the 15th century. The cassava root's ability to withstand drought and poor soil make the plant an essential food for over 500 million people in Africa, according to a June 2009 article in "Comprehensive Reviews in Food Science and Food Safety." Cassava provides calories and protein but lacks other important nutrients.

Major Nutrients

Cassava root yields more energy per acre than corn, rice or sweet potatoes. Because the root grows well in tropical conditions on marginal land, many African subsistence farmers grow cassava as a staple crop. Raw cassava holds 160 calories in 100 g of root, about twice the energy in the same amount of raw potato. The root yields two-thirds as much protein as potatoes and nearly as much vitamin C. Processing reduces cassava's vitamin content and removes important fiber. Processed tapioca yields 88 g of carbohydrate and 358 calories per 100 g. Tapioca retains about 15 percent of the protein found in the raw root.

Minor Nutrients

If you depended on cassava root for most of your food, your diet would lack many important vitamins and some minerals. Cassava provides important amounts of calcium, copper, zinc and potassium, with as much of these essential minerals as found in most beans and peas. Cassava contains low amounts of B vitamins and little vitamin A. Corn and sorghum grains provide a better nutritional balance than cassava. Processed tapioca retains the original calcium in cassava root and concentrates the iron, but loses most of the other minerals such as potassium, magnesium and phosphorous. Processed tapioca loses nearly all the plant's original vitamin content.

Potential

Improvements in cassava could benefit hundreds of millions of people dependent on cassava for much of their daily calories. Genetic modification could increase cassava's disease resistance and improve the vitamin and mineral content, according to a September 2000 article in the "Cornell Chronicle." Gene manipulation and crossbreeding with wild cassava strains could increase protein content by five times. Developing cassava plants with yellow or orange coloration could provide beta-carotene, a precursor of vitamin A. Crossing domestic strains with high protein wild strains also brings problems, since many types of cassava contain dangerous levels of cyanide.

Toxicity

All cassava plants contain cyanogenic glucosides. Different grades of cassava require different amounts of processing before eating. The sweetest cassava strains contain from 40 to 130 ppm of cyanide, mostly in the peel. With less than 50 ppm, the root is safe to eat, according to the Food Safety Network. Peeling and boiling sweet cassava drops the concentration to safe levels. Cyanide could reach almost 500 ppm in the most bitter cassava strains. Processing these begins with grating, soaking and fermenting the root. Drying the root for storage and boiling the dried root before serving removes the rest of the cyanide along with many beneficial compounds.