Although saliva has commonly been used to teach about digestion by organisms, the phenomenon of digestion is actually caused by enzymes as catalytic substances. This activity explores the hydrolysis of starch by "a"-amylase in cleaning materials as well as a comparison with the similar reaction using human saliva. The fact that the "a"-amylase contained in the cleaning materials catalyzes hydrolysis of starch without saliva may remind students of the aspect of an enzyme as a chemical material. In addition, discovering the difference in the reactions between cleaning materials and human saliva at higher temperatures may be a useful educational approach for explaining the stability and denaturation of enzymes in an engaging way that deepens students' understanding.