Effect of Steaming and Roasting Treatment on the Radical Scavenging Activities and Total Ascorbic Acid Content of Persimmon Leaf Tea During Storage

Changes in Total Ascorbic acid (T-AsA) content and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activities during storage of persimmon leaf tea of ‘Saijo’ subjected to steam and/or roast treatments ware investigated using persimmon young leaves. The obtained results were as follows : (1) The steaming treatment for 5 minutes without roasting provided the highest T-AsA content. (2) In non-steaming treatment, T-AsA was remained only by roasting treatment before storage. (3) In the steaming treatment for 5 minutes, the same level of T-AsA content was maintained by the roasting treatments before and after storage. (4) T-AsA and other polyphenols may affect the DPPH radical scavenging activities of persimmon leaf tea. (5) It was thus concluded that the suitable steaming and roasting treatments could produce persimmon leaf tea containing higher T-AsA content and DPPH radical scavenging activities.