Phytosterol and Tocopherol Components in Extracts of Corn Distiller's Dried Grain

Abstract

As the ethanol industry continues to grow, it will become very important to develop value-added markets for its coproducts in order for the industry to remain profitable. Corn distiller's dried grain (DDG) is a major coproduct of ethanol fermentation from corn processed by dry-milling and is primarily sold as livestock feed. The objective of this research was to determine if valuable phytochemicals found in corn oil and corn fiber oil, such as phytosterols and their saturated equivalents, phytostanols, ferulate phytosterol esters (FPE), tocopherols, and tocotrienols, are retained in DDG. Hexane and supercritical carbon dioxide (CO2) extracts of DDG were similar in their concentrations of total phytosterols (15.8-17.3 mg/g of extract), FPE (3.75-3.99 mg/g of extract), and tocols (1.7-1.8 mg/g of extract). Ethanol extracts were slightly lower in concentration of phytosterols (8.9-11.4 mg/g of extract), FPE (1.62-1.98 mg/g of extract), and tocols (0.73-0.76 mg/g of extract).

Plant Sterol and Policosanol Characterization of Hexane Extracts from Grain Sorghum, Corn and their DDGS

“…Similar predominance of sitosterol has also been observed by Winkler et al [17]. Brassicasterol was also identified in some of the samples but only at trace levels.…”

“…For the latter study, two HPLC methods that were capable of detecting free sterols, steryl ferulates and long-chain fatty acid esters of sterol were applied to the samples. Singh et al [15] compared extracts from corn and grain sorghum kernels, similar to the present study, and reported greater amounts of PS in ground corn (88.01 mg of total PS/100 g) than in ground [17] compared five different combinations of methods and solvents to extract PS from corn DDG. They observed levels of PS in corn DDG ranging from 192 to 291 mg of total PS/100 g of corn DDG.…”

“…Furthermore, Singh et al [15] observed types of PS in grain sorghum kernels, grain sorghum wet milling fractions, and comparable corn kernels and corn wet milling fractions. Srinivasan et al [16] reported PS composition of an unknown commercially produced DDGS sample whereas Winkler et al [17] investigated corn DDG of Iowa origin. None of these studies had observed PS levels in grain sorghum DDGS and compared it to grain sorghum kernels, corn kernels, and corn DDGS under similar extraction conditions.…”

Preparation and Evaluation of Jojoba Oil Methyl Esters as Biodiesel and as a Blend Component in Ultra-Low Sulfur Diesel Fuel

“…Oils samples were saponified and phytosterols were extracted essentially as described by Dutta et al [20,21]. Phytosterols were manually injected onto a Varian 3400 GC equipped with an FID and a Supelco (Bellefonte, PA, USA) SPB™-1701 (30 m×0.25 mm×0.25µm) capillary column.…”

“…Phytosterols were identified by comparison of their retention times (relative to the internal standard, 5α-cholestane) with those of commercially available standards. Phytosterols without commercially available standards, such as Δ5-avenasterol, were identified by their relative retention time compared to literature [20,21] and by comparison with samples known to contain those phytosterols. Quantitation was carried out by the internal standard method developed with available standards.…”