At breakfast some sugar from the sugar bowl may be added to the fruit. Many people add sugar to the oatmeal or other cereal eaten, although it is often held by teachers of dietetics that this is not a good place to use it, for proper cooking and thorough mastication of the cereal will bring out a rich sweetness due to changes explained later. Country boys know how sweet a morsel is made by chewing raw grains, especially wheat. Possibly a glass of milk is taken at breakfast and this contains another kind of sugar - milk sugar - in about 5 per cent. Coffee and tea are usually sweetened, so that a considerable part of the breakfast may be of this class of foods - a quickly burning material giving heat and energy.
There are several different sugars recognized by chemists; these are cane sugar or sucrose, grape sugar or glucose, milk sugar or lactose, and fruit sugar or levulose. Cane sugar is obtained from the juices of many plants, notably sugar beets, sugar cane, the palm, and as maple sugar from the rock-maple trees. Molasses and brown sugar are obtained during the manufacture of white sugar from sugar cane. Cane sugar is composed of carbon, hydrogen, and oxygen in the proportion of twelve parts of carbon to eleven parts of water. When sugar is heated it is chemically changed, more or less, according to the degree of heat and the rapidity with which it parts with its water.
Heating it gradually, we obtain first straw colored barley sugar, then brown caramel,- and finally black carbon.
Grape sugar is found in honey and in all ripe fruits. It consists of carbon, hydrogen, and oxygen in somewhat different proportions from what they occur in cane sugar. It appears on the outside of dried fruits, such as raisins. It is only two-fifths as sweet as cane sugar. Large quantities are manufactured from corn starch.
Milk sugar is similar to cane sugar in composition. It is obtained from the whey of milk. It is hard and gritty and not very sweet to taste. When milk sours, it is because this sugar is fermented and changed into lactic acid. The acid causes the milk to curdle.
Fruit sugar or levulose occurs with glucose (grape sugar) in fruits. It is about as sweet as cane sugar but it does not crystallize.
A marked characteristic of all sugars is their solubility and all but the last are crystalline substances, that is, will form crystals.
At breakfast bread, toast, or some cereal like oatmeal or wheat, usually follows the fruit course." These foods are prepared from grains (seeds) and contain much nutriment in a condensed form. They supply the body with starch and some nitrogenous food. But the body cannot use starch as such. It must be changed into a form of sugar called starch sugar, or maltose. While we are following Mr. Gladstone's rule and chewing each mouthful of our toast twenty-five times, we will consider what starch is like and how it is made available for use.
Starch is found in greater or less abundance in all plants and is laid up in large quantities in the seeds of many species. See Fig. 14. Rice is nearly pure starch; wheat and the other cereals contain sixty to seventy per cent of it. Some tubers, such as potatoes, contain it although in less quantity - ten to twenty per cent.
It is formed by means of the living plant-cell and the sun's rays, from the carbon dioxide and water contained in the air and it is the end of the plant - life - the stored energy of the summer. It is prepared and stored by the parent for the food for the young plant until the latter can start its own starch factories.
Starch in its common forms is insoluble in water. It dissolves partially in boiling water, forming a trans parent jelly when cooled, as every housekeeper knows. The cellulose which occurs in various forms in the shells and skins of fruits, in their membraneous partitions, and in cell walls, is an allied substance.
Source of Starch