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ARS Home » Plains Area » Manhattan, Kansas » Center for Grain and Animal Health Research » Grain Quality and Structure Research » Research » Publications at this Location » Publication #166688


item Ram, M
item Chung, Okkyung

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2004
Publication Date: 8/1/2004
Citation: Ram, M.S. and Chung, O.K. 2004. Wheat flour lipids extracted by a dual-pump CO2 -ethanol supercritical fluid extraction system. Abstract A-01. Page 160 in: Program Book of the 11th International Symposium and Exhibit on Supercritical Fluid Chromatography, Extraction, and Processing, Pittsburgh, PA (August 1-4, 2004).

Interpretive Summary:

Technical Abstract: Supercritical fluid CO2 (SF-CO2) is a useful system for extracting nonpolar lipids (NL) from wheat flour. However, a polar modifier, such as ethanol, is necessary to extract the polar lipids (PoL) and the amount of lipids extracted by a supercritical fluid extraction (SFE) system varies with the % modifier used (Fig. 1). In our research the extracted lipids were fractionated on silica solid-phase extraction cartridges to obtain the NL and PoL composition. Previously, we have reported that SF-CO2 at 7,500 psi and 80oC with 12% (v/v) ethanol as a modifier extracted all the free lipids (FL) from wheat flour (J.D. Hubbard, J.D. Downing, M.S. Ram, and O.K. Chung, Cereal Chem., in press). The objective of this study was to test the feasibility of sequentially extracting FL from wheat flour so that we do not have to fractionate the extracted FL in to the NL and PoL fractions. We have used four Hard Red Winter wheat flours to develop the sequential extraction (SEx) method for flour FL using SFE. First, the NL fraction of flour FL was extracted by using SF-CO2 only (1st SEx), and then the PoL fraction was extracted with the addition of modifier ethanol to SF-CO2 (2nd SEx). Lipids were extracted by SEx and the one-step SFE method from four flours (Table I). The amounts of lipids extracted by 1st and 2nd SEx were in agreement with the amounts of NL and PoL fractionated from the FL by the one-step extraction. The success of the sequential extraction is evidenced by the TLC chromatograms in which the individual components of NL and PoL could be qualitatively determined (Fig. 2). Note that in Fig. 2A, lanes 1 and 4 (1st SEx) contained NL only, lanes 2 and 5 (2nd SEx) contained only PoL (Fig. 2B) that did not migrate. Lanes 3 and 6 were extracted by the one-step SFE method and they contained both NL and PoL. These results indicate that we succeeded in our goal of fractionating wheat flour lipids using SEx without the need for a separate fractionation step after the SFE extraction.