373 Preliminary results of desirable lipid wheat screening.

R. L. MADL (1) and D. L. Wetzel (2). (1) Wheat Research Center, Waters Hall, Kansas State University, Manhattan, KS 66506; (2) Shellenberger Hall, Kansas State University, Manhattan, KS 66506.

Genetically incorporating desirable lipids as a factor in wheat quality for breadmaking (once protein quantity and quality factors have been achieved) is the objective of a new screening procedure for the Kansas AES breeding program. In particular, digalactosyl diglyceride (DGDG), known to influence loaf volume, is screened by a method involving selective (two-step) supercritical fluid extraction to isolate the polar lipids quickly and efficiently for subsequent quantitation by HPLC or SFC. Preliminary results are reported from a new screening project designed to support the wheat breeding efforts in a way similar to the infrared wheat protein screening initiated in 1977 that resulted in 2.5% absolute protein increase. The modern analytical method used was developed in the analytical research group at KSU in 1997. It employs a 15 minute supercritical extraction with CO(2) to remove nonpolar lipid prior to a 15 minute recovery of the polar lipid fraction with a supercritical methanol modified CO(2) mixture. The polar fraction that is free of phospholipids is analyzed by an automated high performance liquid chromatographic procedure. This replaces a 22 hour extraction, open column fractionation and HPLC method also developed at KSU in 1979. Several 1998 crop experimental wheats were tested for DGDG preliminary to routine analysis of select 1999 crop wheat breeding samples.