In 1995, Hefle became a Research Assistant Professor of Food Science and Technology at the University of Nebraska–Lincoln.
Hefle authored or co-authored over 130 peer-reviewed publications and earned two patents as a result of her efforts.
Hefle received the Institute of Food Technologists (IFT) Samuel Cate Prescott Award in 2000.
Hefle also was named fellow of the American Academy of Allergy, Asthma, and Immunology in 2003.
As a member of IFT, Hefle was active in leadership role in the organization's Biotechnology, and Toxicology & Safety Evaluation divisions, was a Scientific Lecturer, a member of the Biotechnology Issues Task Force, and a Council Representative to the IFT Executive Committee.
In the mid-1990s, she founded American Bicycle Racing (ABR) in Tinley Park, Illinois in order to bring out more grass roots cycling and support to junior and master-level riders that USA Cycling was neglecting.