The optimum pH of salivary amylase is approximately 6.7 to 7, according to Worthington Biochemical Corporation, meaning very slightly acidic. If the pH is significantly out of this range, the enzyme performs sub-optimally, and eventually becomes denatured, at which point it no longer functions, notes Encyclopaedia Britannica.
Medical Dictionary states that salivary amylase is an enzyme produced by the saliva glands to catalyse the hydrolysis, or breaking down, of starch into smaller, simpler compounds. Enzymes such as amylase are very important in digestion since humans cannot directly absorb starch and other large, complex molecules. The pancreas also secretes amylase to aid in digestion.