ARS | Publication request: Angiotensin I Converting enzyme inhibitory peptides from commercial wet- and dry-milled corn germ

Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 7, 2008
Publication Date: February 7, 2008
Citation: Parris, N., Moreau, R.A., Johnston, D., Dickey, L.C., Rotimi, A.E. 2008. Angiotensin I Converting enzyme inhibitory peptides from commercial wet- and dry-milled corn germ. Journal of Agricultural and Food Chemistry. 56(8):2620-2623.

Interpretive Summary: Commercially corn oil is extracted from corn germ with a solvent called hexane. Due to potential explosion hazards, as well as human and environmental safety issues associated with the use of hexane,hexane extraction plants have become increasingly expensive to build, run, and maintain. As part of a project on the extraction of corn oil from corn germ using only water and enzymes (no hexane), the objective of this research was to develop bioprocesses to efficiently separate protein-enriched fractions from the process as potentially valuable coproducts. We have identified conditions leading to the formation or isolation of fractions which may reduce blood pressure in animals and humans and could potentially be used for promoting health and preventing disease. Results from this study will benefit food and nutritional scientists who are trying to develop valuable new protein-based food and nutraceuticals.

Technical Abstract: Bioprocesses were developed to enhance the value of proteins from de-oiled corn germ. Proteins were hydrolyzed with trypsin, GC106, Flavourzyme or thermolysin in order to free the bioactive peptide sequences. Protein hydrolysis, at an enzyme to substrate ratio of 1:250, was greater for wet- than dry-milled corn germ. Electrophoretic patterns indicated that hydrolysis for 1.5 h was adequate for generating low molecular weight peptides for both germs. Dry-milled corn germ hydrolyzed with trypsin, thermolysin or Flavouzyme and wet-milled germ hydrolyzed with thermolysin generated ACE-inhibitory peptides as did unhydrolyzed wet- but not the dry-milled corn germ.