Starch
Starch is one of the most important carbohydrates used for nutrition. It is formed by the chemical action produced by the sun’s rays upon the cells of living plants, from the carbon-dioxid and water in the air and in the soil.
Corn starch, sago, tapioca, and arrowroot are practically pure starch. Cornstarch is from young maturing corn; tapioca is from the meal of a tropical plant, cassava; sago is from the pith of the sago palm; arrowroot is from a plant of the same name, a native of the West Indies. Rice is almost pure starch, while wheat and other cereals contain from sixty to seventy per cent.
Starch lacks flavor and for this reason all starchy foods are seasoned.
All starches must undergo much chemical change by action of the saliva, the intestinal juice and by the liver, before they can be used by the body. They are first converted into dextrine and then into maltose (animal sugar). The digestion is begun by the saliva in the mouth and continued in the stomach by the saliva swallowed with the food. If the saliva fails to digest all of the starch, either in the mouth or the stomach, it passes unchanged into the intestines, where it is converted by the amylase of the intestinal juice, first into dextrine and then into maltose, or sugar. It is absorbed into the blood as sugar. After the digested starch (maltose) passes into the blood it is spoken of as sugar. Before it is converted into energy it is again changed in the liver into animal starch (glycogen) and stored for a time in the liver. When the system is ready for it, it is again broken down into sugar, because in the form of glycogen it cannot be absorbed into the blood.
The chemical process used in the formation of glucose, from the starch in corn, is allied to the change in the liver, from starch into sugar.
The starches and sugars are really the “reserves” or “go-betweens” of the body, being stored until needed.
If starches are consumed in unduly large quantities, without sufficient exercise to burn them up, they overload the liver and clog the system.
Starchy foods should not be given to children before the starch converting ferments are formed, nor to one in disease where these ferments are interrupted.