Ms Ruddenklau, who is beauty co-ordinator and tutor at the polytechnic's Oamaru campus, was this week presented with the award for excellence in teaching and learning.
One person from each of the polytechnic's six campuses was nominated, and two awards were given.
One of the awards was presented to Ms Ruddenklau, and the other to hospitality tutor Adrian Hilhorst, who is based at the polytechnic's Timaru campus.
Aoraki Polytechnic employs 184 tutors.
Ms Ruddenklau, who has been working at the polytechnic since 2007, said she "absolutely loved" her job.