Study on the substrate specificity of α‐amylases that contribute to soil removal in detergents

The actions of α‐amylases in the degradation of amylose and amylopectin were investigated, and the contribution of the enzymatic hydrolysis of high‐viscosity gelatinized starch to the removal of food stains that contain starch was characterized. α‐Amylases from Bacillus amyloliquefaciens, B. licheniformis, Aspergillus oryzae, and porcine pancreas were used to test the removal of curry stains, which are hard to remove under low‐temperature washing conditions and include large amounts of starch. In a detergent, the enzyme from B. amyloliquefaciens was the most effective in removing stains and hydrolyzed amylopectin more efficiently than amylose as a result of the more efficient formation of an enzyme‐substrate complex in the former case. It is suggested that the cleaning power of α‐amylases is due to their hydrolytic action, with endo‐degradation of amylopectin, which results in an efficient reduction in the degree of polymerization. The liquefaction of amylopectin then accelerates the removal of food stains.