Submitted to: National Meeting of Institute of Food Technologists/Food Expo
Publication Type: Abstract Only
Publication Acceptance Date: 3/21/2007
Publication Date: 7/26/2007
Citation: Moser, J.K., Rennick, K.A., Vaughn, S.F., Eller, F.J. 2007. Phytosterol and Tocopherol Components in Extracts of Corn Distiller's Dried Grain (DDG). National Meeting of Institute of Food Technologists/Food Expo. 00:000-000. Interpretive Summary:
Technical Abstract: Corn distiller’s dried grains (DDG) is the major by-product of ethanol fermentation from corn processed by dry-milling. DDG is high in fiber, protein, and fat, and is sold primarily for livestock feed. It is currently valued at approximately $85-110 per ton. The ethanol industry is expected to grow tremendously, thus it will be important to find value-added uses for its byproducts. Corn oil and corn fiber oil, by-products of the corn wet-milling process, contain several unique and valuable phytochemicals such as phytosterols and their saturated equivalents, phytostanols, ferulate-phytosterol esters (FPE), tocopherols and tocotrienols. Since ethanol fermentation utilizes starch only, it is expected that the same phytochemicals that are found in corn and corn fiber oil may be retained in DDG. The objective of this research was to analyze hexane, ethanol, and supercritical CO2 (CO2) solvent extracts for phytosterol, FPE, and tocopherol content. Soxhlet extraction vs. pressurized heated extractions with hexane and ethanol were also compared. Total phytosterols were determined by saponification and GC analysis. FPE and tocopherols were determined by HPLC with UV and fluorescence detection, respectively. Phytosterols, FPE, and gamma tocopherol were found in all DDG extracts. Total phytosterol content was highest in the hexane and CO2 extracts of DDG (16.4-17.6 mg/kg and 15.86 mg/kg, respectively), while ethanol extracts contained 11.6-12.2 mg/kg. FPE content was also higher in hexane and CO2 extracts (4.3-4.4 mg/kg) compared to ethanol extracts (2.4-3.8 mg/kg). Gamma tocopherol was found at levels of 0.85-0.90 mg/kg in hexane and CO2 extracts, and 0.39-0.76 mg/kg in ethanol extracts. Although the concentration of phytochemicals was higher in hexane and CO2 extracts, ethanol extracts actually contained more total phytosterols, FPE, and gamma tocopherol. This research indicates that extracts of DDG have high content of some valuable nutraceuticals, which may provide an additional market for ethanol producers to sell DDG.