Dennis R. Heldman was awarded B.S. (1960) and M.S. (1962) degrees from The Ohio State University, and a PhD (1965) from Michigan State University. His educational background emphasized the application of engineering principles and concepts to the processing of foods. 

In 1966, Dr. Heldman joined the faculty at Michigan State University, and began teaching and research in the area of food process engineering. In 1975, the first edition of Food Process Engineering (by Heldman), a textbook for undergraduate engineering students, was published. He served as Chair of the Agricultural Engineering Department at Michigan State University from 1975 to 1979. In 1981, the second edition of Food Process Engineering (with R. Paul Singh) was published, and in the 1984, the first edition of Introduction to Food Engineering (with R. Paul Singh) was published. 

Dr. Heldman joined the Campbell Soup Company in 1984, as the Vice President of Process Research and Development. In 1986, he moved to the National Food Processors Association, as Executive Vice President of Scientific Affairs, and CEO for The National Food Laboratory, and President of The Food Processors Institute. In 1991, Dr. Heldman joined the Weinberg Consulting Group Inc, and was involved in consulting on food regulatory issues. In 1992, the first edition of the Handbook of Food Engineering (Heldman and Daryl B. Lund as Co-Editors) was published.

In 1992, Dr. Heldman was appointed Professor of Food Process Engineering at the University of Missouri and Leader for the Foods, Feeds and Products cluster in the Foods for the 21st Century program; he was involved in teaching and research in food engineering.  Beginning in 1994, he served as Unit Leader for the Food Science and Engineering Unit, and in 1997, as Director for the Office of Value-Added Agriculture Outreach.  In 1993, the second edition of Introduction to Food Engineering (with R. Paul Singh) was published, and in 1997, Principles of Food Processing (with Richard W. Hartel) was published.  

From 1998 to 2004, Dr. Heldman was Professor of Food Process Engineering at Rutgers, the State University of New Jersey, and Director of the Cooperative Research & Development Program in the Center for Advanced Food Technology (CAFT).  The third edition of Introduction to Food Engineering (with R. Paul Singh) was published in 2001.  In 2003, the print edition of the Encyclopedia of Agricultural, Food and Biological Engineering (Heldman as Editor) was published; the print edition has been followed by quarterly on-line up-dates.  

From 2004 to 2012, Dr. Heldman was a consultant involved in applications of engineering concepts to food processing for educational institutions, industry and government.  These activities include publication of the second edition of the Handbook of Food Engineering (with Daryl B Lund) in 2007.  In 2008, the fourth edition of Introduction of Food Engineering (with R. Paul Singh) was published.  More recently, the Encyclopedia of Biotechnology in Agriculture and Food (Heldman as Editor) was published in 2010, followed by the second edition of the Encyclopedia of Agricultural, Food and Biological Engineering (with Carmen I. Moraru as Co-Editor).  In 2011, a new text/reference book entitled Food Preservation Process Design (authored by Heldman) was published. 

Heldman served as President of IFT, the Society for Food Science and Technology, from 2006-07.  He was elected Fellow in the International Academy of Food Science & Technology in 2006.  He served as President of Phi Tau Sigma, the Honorary Society for Food Science and Technology from 2010-11. Heldman was recognized with the Life Achievement Award from the International Association for Engineering and Food in Athens, Greece in May, 2011.  He presented the 2011 Bernard E. Proctor Food Engineering Division Lecture at the Annual IFT Meeting in New Orleans.  In August, 2011, Heldman was recipient of the Frozen Food Foundation Freezing Research Award and was recipient of the Carl R. Fellers Award from the IFT and Phi Tau Sigma in 2013. Most recently, Heldman received the Harold Macy Food Science and Technology Award from the Minnesota Section of IFT in March, 2017.

In August, 2012, Heldman joined the faculty at The Ohio State University as Dale A. Sobering Endowed Professor of Food Engineering.  He is involved in teaching and research in the area of food engineering, with a focus on sustainability of the food system, and specifically on improvement in process efficiencies while enhancing product quality.