Characterization of honey amylase

ABSTRACT:  The major α-amylase in honey was characterized. The optimum pH range and temperature were determined for the enzyme as 4.6 to 5.3 and 55 °C, respectively. The enzyme was stable at pH values from 7 to 8. The half-lives of the purified enzyme at different temperatures were determined. The activation energy for heat inactivation of honey amylase was 114.6 kJ/mol. The enzyme exhibited Michaelis–Menten kinetics with soluble starch and gave K _M and V _max values of 0.72 mg/mL and 0.018 units/mL, respectively. The enzyme was inhibited by CuCl (34.3%), MgCl₂ (22.4%), and HgCl₂ (13.4%), while CaCl₂, MnCl₂, and ZnSO₄ did not have any effect. Starch had a protective effect on thermal stability of honey amylase. Therefore, it might be critical to process or control the amylase in honey before incorporation into starch-containing foods to aid in the preservation of starch functionality. One step could involve heat treating honey with other ingredients, especially those that dilute and acidify the honey environment.