What edible substances dissolve in saliva?
Starch will begin to be broken down into simpler polysaccharide molecules by salivary amylase. The enzyme lipase is also present in saliva but is usually inactive at the pH of saliva (around pH 6.2) and consequently will not act upon lipids (fats and oils) until it reaches the stomach where the pH is lower (and nearer to the enzyme's optimum PH.)
Polar substances will dissolve other polar substances.* Ionic substances will dissolve other ionic substances Nonpolar substances will dissolve other nonpolar substances. *Water is called the universal solvent because it can dissolve both polar and ionic substances. (Although not all ionic substances will be dissolved by water.)
The bonding characteristics of the solute and solvent determine if a solute will dissolve in a given solvent. Typically, the rule "like dissolves like" applies. Substances with like bonds will be soluble in one another. Thus, polar substances dissolve polar substances, while nonpolar substances dissolve nonpolar substances.
Substances that dissolve other substances are called solvents. Substances that dissolve into other substances are called solutes. There is no easy list of substances that dissolve but sugar (sucrose) dissolves in water, table salt (NaCl) dissolves in water, wax dissolves in petrol (gasoline) or in ethanol or acetone.
Typically, the rule "like dissolves like" applies to solvents. Substances with like bonds will be soluble in one another. Thus, polar substances dissolve polar substances, while nonpolar substances dissolve nonpolar substances. This results from the nature of the bonds that are broken and formed in the process of solvation, and their relative energies.