Beyond its contributions as a sweetener and flavor-enhancer, sugar:
1. Interacts with molecules of protein or starch during baking and cooking process.
2. Acts as a tenderizer by absorbing water and inhibiting flour gluten development, as well as delaying starch gelatinization
3. Incorporates air into shortening in the creaming process.
4. Caramelizes under heat, to provide cooked and baked foods with pleasing color and aroma.
5. Speeds the growth of yeast by providing nourishment.
6. Serves as a whipping aid to stabilize beaten egg foams.
7. Delays coagulation of egg proteins in custards.
8. Regulates the gelling of fruit jellies and preserves.
9. Helps to prevent spoilage of jellies and preserves.
10. Improves the appearance and tenderness of canned fruits.
11. Delays discoloration of the surface of frozen fresh fruits.
12. Enables a wide variety of candies through varying degrees of recrystallization.
13. Controls the reformation of crystals through inversion (breakdown to fructose and glucose).
14. Enhances the smoothness and flavor of ice cream.
Sugar prevents spoilage of jams, jellies, and preserves after the jar is opened. Properly prepared and packaged preserves and jellies are free from bacteria and yeast cells until the lid is opened and exposed to air. Once the jar is opened, sugar incapacitates any microorganisms by its ability to attract water. This is accomplished through osmosis (the process whereby water will flow from a weaker solution to a more concentrated solution when they are separated by a semi-permeable membrane). In the case of jellies and preserves, the water is withdrawn from these microorganisms toward the concentrated sugar syrup. The microorganisms become dehydrated and incapacitated, and are unable to multiply and bring about food spoilage. In jellies, jams and preserves, a concentrated sugar solution of at least 65% is necessary to perform this function. Since the sugar content naturally...