Characterization of honey amylase.
The major alpha-amylase in honey was characterized. The optimum pH range and temperature were determined for the enzyme as 4.6 to 5.3 and 55 degrees 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 KM and Vmax 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.
Babacan
Sibel
S
Food Science Research Center, Univ. of Rhode Island, 530 Liberty Lane, West Kingston, RI 02892, USA.
Rand
Arthur G
AG
D000143:Acids / Q000494:pharmacology*; D004789:Enzyme Activation; D004795:Enzyme Stability; D006722:Honey / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D000516:alpha-Amylases / Q000032:analysis* / Q000037:antagonists & inhibitors* / Q000378:metabolism
D000143:Acids; D013213:Starch; D000516:alpha-Amylases