Chopped and frozen with nothing added, stored in a zipper-lock bag for two weeks.
Chopped, placed in an ice cube tray, and frozen covered with water. Transferred to a zipper-lock bag and stored for two weeks.
Blanched briefly in boiling water, chilled, chopped, placed in an ice cube tray, and frozen covered with water. Transferred to a zipper-lock bag and stored for two weeks.
Chopped, placed in an ice cube tray, and frozen covered with oil. Transferred to a zipper-lock bag and stored for two weeks.
I also included a set of freshly chopped herbs in my taste tests as a control.