Angiotensin I converting enzyme-inhibitory peptides from commercial wet- and dry-milled corn germ.

Bioprocesses were developed to enhance the value of proteins from deoiled corn germ. Proteins were hydrolyzed with trypsin, thermolysin, GC 106, or Flavourzyme to generate the bioactive peptide sequences. At an enzyme to substrate ratio of 1:100, protein hydrolysis of wet-milled germ was greatest using thermolysin followed by trypsin, GC 106, and Flavourzyme.

Protein distribution in commercial wet- and dry-milled corn germ.

To identify high-valued coproducts from commercially processed corn germ, it was necessary to determine the effect of processing conditions on corn germ proteins. We found that significantly less protein was extracted from commercial wet-milled as compared to dry-milled corn germ using Tris, sodium dodecyl sulfate (SDS) buffer containing 14 mM 2-mercaptoethanol at 100 degrees C for 10 min. SDS-polyacrylamide gel electrophoresis (PAGE) revealed a number of proteins with molecular masses ranging from approximately 10 to 66 kDa for the dry-milled corn germ as compared to only a few significant protein bands centered around 23 kDa in the wet-milled corn germ.

Adhesive properties of corn zein formulations on glass surfaces.

Adhesive properties on glass of commercial zein and an inexpensive zein-lipid mixture isolated from dry-milled corn were investigated. A method was developed for uniformly preparing bonded glass panels and measuring the amount of pull required to separate the panels. The adhesive strength of commercial zein to glass was greater at 29% than at 52% relative humidity (RH).

Effect of endogenous triacylglycerol hydrolysates on the mechanical properties of Zein films from ground corn.

Dry-milled yellow corn and freshly ground food and nonfood grade yellow and white hybrid corn kernels were pretreated in a solution of lactic acid and sodium metabisulfite followed by extraction with 70% ethanol. Zein was precipitated from the extract by reducing the ethanol content of the extract to 40%. Lipid associated with the zein isolates was between 15 and 20% and contained mostly endogenous free fatty acids.