The NutriPure Team.

Stephen’s Bio

Founded in 2002 by Stephen Kelleher, Ph.D., Proteus Industries is the company behind our original product NutriLean® and our new and improved product NutraPure®. A renown food chemist, Dr. Kelleher spent years doing protein and lipid research with Advance Protein Technologies, and as a researcher at UMass-Amherst Marine Station in Gloucester, MA.

Dr. Kelleher earned his Ph.D. from the University of Massachusetts at Amherst and an M.S. from Cornell University. He has received numerous honors and awards and maintains membership in organizations that include American Chemical Society and the Institute of Food Technologists.


For a little light reading, here is a list of his published works:

  • Kelleher, S.D., Feng, Y., Kristinsson, H., Hultin, H.O. and McClements, D.J. Functional fish protein isolates prepared using low ionic strength, acid solubilization/precipitation. In: Developments in Food Science, More Efficient Utilization of Fish and Fisheries Products, Elsevier Science Pub., Amsterdam, pp. 407-414.

  • Kelleher, S.D., Feng, Y., Hultin, H.O. and Livingston, M.B. Role of initial muscle pH on the solubility of fish muscle proteins in water. J. Food Biochem. 28:279-292.

  • Park, Y., Kelleher, S.D., McClements, D.J. and Decker, E.A. Incorporation and stabilization of Omega-3 fatty acids in surimi. J. Agric. Food Chem. 52(3):597-601.

  • Opiacha, J., Hultin, H.O., Huang, C-H. and Kelleher, S.D. Improvements in stability and functionality of fatty fish surimi. In: Food Functionality: Physico-chemical and Biological. Z.U. Haque (ed.), CRC Press, Boca Raton, FL.

  • Undeland, I., Kelleher, S.D., Hultin, H.O., McClements, D.J. and Thongraung, C. Consistency and solubility changes in herring (clupea harengus) light muscle homogenates as a function of pH. J. Agric. Food Chem. 51 (14):3992-3998.

  • Undeland, I., Hultin, H.O. and Kelleher, S.D. Recovery of functional proteins from herring (clupea harengus) light muscle by an acid or alkaline solubilization process. J. Agric. Food Chem. 50(25):7371-7379.

  • Kelleher, S.D., Livingston, M.B., Hultin, H.O. and Aciukewicz, T.J. Characteristics and storage stability of Atlantic hagfish. J. Aquatic Food Process. Technology 10 (4):27.

  • Hultin, H.O. and Kelleher, S.D. Surimi processing from dark muscle fish. In: Surimi and Surimi Seafood. J.W. Park (ed.), Marcel Dekker, New York, pp. 59-77.

  • Kelleher, S.D. Physical characteristics of muscle protein extracts prepared using low ionic strength, acid solubilization/precipitation. Ph.D. Thesis, University of Massachusetts.

  • Kelleher, S.D. and Hultin, H.O. Functional chicken muscle protein isolates prepared using low ionic strength, acid solubilization/precipitation. Proceedings of the 53rd Reciprocal Meat Conference, Columbus, OH, June 18-21, 2000.

  • Kelleher, S. and Hultin. H. A process for isolating functional protein from pelagic fish. Manual of the 7th Annual OSU Surimi Technology School. Oregon State University, Seafood Laboratory.

  • Richards, M.P., Kelleher, S.D. and Hultin, H.O. Effect of washing with or without antioxidants on quality retention of mackerel fillets during refrigerated and frozen storage. J. Agric. Food Chem. 46(10):4363-4371.

  • Jia, Tian-dong, Kelleher, S.D., Hultin, H.O., Petillo, D., Maney, R. and Krzynowek, J. Comparison of quality loss and changes in the glutathione antioxidant system in stored mackerel and bluefish muscle. J. Agric. Food Chem. 44(5):1195-1201.

  • Krishnamurthy, G., Chang, H.S., Hutlin, H.O., Feng, Y., Subramarian, S. and Kelleher, S.D. Solubility of chicken breast muscle proteins in solutions of low ionic strength. J. Agric. Food Chem. 44(2):408-415.

  • Bakir, H.M., Hultin, H.O. and Kelleher, S.D. Gelation properties of fatty fish processed with or without added NaCl, cryoprotectants and antioxidants. Food Res. Internat. 27:443-449.

  • Bakir, H.M., Hultin, H.O. and Kelleher, S.D. Some properties of fish gels made from several Northwest Atlantic species in the presence of high and low salt. J. Food Process. Preserv. 18:103-117.

  • Kelleher, S.D., Hultin, H.O. and Wilhelm, K.A. Stability of mackerel surimi prepared under lipid-stabilizing processing conditions. J. Food Sci. 59(2):269-271.

  • Xing, Y., Yoo, Y., Kelleher, S.D., Nawar, W.W. and Hultin, H.O. Lack of changes in fatty acid composition of mackerel and cod during iced and frozen storage. J. Food Lipids 1:1-14.

  • Kelleher, S.D. Silva, L.A., Hultin, H.O. and Wilhelm, K.A. Inhibition of lipid oxidation during processing of washed, minced Atlantic mackerel. J. Food Sci. 57:1103-1108,1119.

  • Hultin, H.O., Decker, E.A., Kelleher, S.D. and Osinchak, J.E. Control of lipid oxidation processes in minced fatty fish. In: Seafood Science and Technology. E.G. Bligh (ed.), Fishing News Books, Oxford, UK pp. 93-100.

  • Osinchak, J.E., Hultin, H.O., Zajicek, O.T., Kelleher, S.D. and Huang, C-H. Effect of NaCl on catalysis of lipid oxidation by the soluble fraction of fish muscle. Free Radical Biol. Med. 12:35-41.

  • Xing, Y., Yoo, Y. Kelleher, S.D., Silva, L.A., Halpin, B.E., Nawar, W.W. and Hultin, H.O. Stability of n-3 fatty acids of fish during processing and storage. In: Process Induced Chemical Changes in Food Composition. D.J. Armstrong and S.W. Page (eds.)

  • Kelleher, S.D. and Hultin, H.O. Lithium chloride as a preferred extractant of fish muscle proteins. J. Food Sci. 56(2):315-317.

  • Nawar, W., Hultin, H.O., Li, Y., Xing, Y. Kelleher, S. and Wilhelm, C. Lipid oxidation in seafoods under conventional conditions. Food Rev. Internat. 6:647-660.

  • Kelleher, S.D. and Zall, R.R. Ethanol accumulations in muscle tissue as a chemical indicator of fish spoilage. J. Food Biochem. 7:87.

  • Hultin, H.O., McDonald, R.E. and Kelleher, S.D. Lipid oxidation in fish muscle microsomes. In: Chemistry and Biochemistry of Marine Food Products. R. Martin, G. Flick, C. Hebard and D. Ward (eds.) AVI Publishing Co., Westport, CT, pp 1.

  • Kelleher, S.D., Buck, E.M., Hultin, H.O., Parkin, K.L., Licciardello, J.J. and Damon, R.A. Chemical and physical changes in red hake blocks during frozen storage. J. Food Sci. 47:65.

  • Regenstein, J.M., Hultin, H.O., Fey, M. and Kelleher, S.D. Utilization of red hake. Mar. Fish. Rev. 42:32.

  • McDonald, R.E., Kelleher, S.D. and Hultin, H.O. Membrane lipid oxidation in a microsomal fraction of red hake muscle. J. Food Biochem. 3:125.


  • Stephen D. Kelleher

    Founder and Chief Scientist

    Stephen D. Kelleher, Ph.D., is an accomplished scientist and food chemist. Following many years of protein and lipid research, Dr. Kelleher founded Proteus Industries in 2001 and he currently serves as Chief Scientist.

    Prior to founding Proteus, Dr. Kelleher was a research scientist at the University of Massachusetts for 14 years focusing on the basic chemistry of lipid oxidation and protein physical properties, mainly in the area of seafood. Dr. Kelleher has also worked in a variety of food service roles with companies such as Campbell Soup Co, and has consulted internationally in Europe and the Middle East. He has published over 50 manuscripts and secured 8 patents with 8 more pending. Dr. Kelleher received his education at University of Massachusetts and Cornell University.

  • Bill Fielding

    Chief Executive Officer

    Bill joined the Proteus team in 2009 to help develop applications for the beef and pork industries. With an extensive background in the food industry, Bill has held management and executive management positions with prominent producer, food service, and meat processing companies within the United States. His experience in processing and understanding of the food service and retail business will help guide expansion projects that provide significant value for multiple segments of the industry.


  • Kevin Pentz

  • Wayne Saunders-Director Key Accounts/Research & Development
  • Craig Schuman-Production Manager Meats/Seafood
  • Josh Manley-Research and Development Manager
  • David Michael Ruesgen-Operations Manager- Colorado Division


Let Us Put NutraPure® To Your Test

Our facility in Gloucester, Massachusetts includes a laboratory, trial production equipment and pilot facility. Together, we can help you learn the best way to make NutraPure® protein work small miracles for your product line.