Phytosterol ferulate esters

Moreau, R.A. Powell, M.J. Hicks, K.B. Norton, R.A. 1998. A Comparison of the levels of ferulate-phytosterol esters in com and other seeds. In Advances in Plant Lipid Research ( Sanchez, J. Cerda-Olmedo, E. Martinez-Force, E.,Eds.) Uni-versidad de Sevilla, Spain, pp. 472 74. 

Supercritical fluid technology has also been investigated for the enrichment of minor oil components. SFE coupled with supercritical fluid chromatography has been investigated for the enrichment of ferulate phytosterol esters from corn bran... 

Com bran obtained as a by-product finm the dry-milling of com and yields an oil that contains the above mentioned phytosterols (28). Ifowever, these ferulate phytosterol esters (FPE) are present at very low levels (l.S wt%) in the predominately triaqrlglycerol (TAG)-based oil. Therefore, enrichment of these moieties is desired since thQr can be used as nutraceuticals, commanding a high value in the functional foods market ( 18-20/kg) (29). 

THE OCCURRENCE AND BIOLOGICAL ACTIVITY OF FERULATE-PHYTOSTEROL ESTERS IN CORN FIBER AND CORN FIBER OIL... 

Figure 1. HPLC-ELSD chromatogram of corn fiber oil. Insert shows the structure of sitostanyl-ferulate, the major ferulate-phytosterol ester in corn fiber oil (Norton, 1995). Abbreviations StE, phytosterol fatty acyl ester TAG, triacylglycerol, a-Toc, a-tocopherol FFA, free fatty acids CE, p-coumarate-phytosterol esters y-Toc, y tocopherol ST, free phytosterols 1,3-D, 1,2-diacylglycerols FE, ferulate-phytosterol esters 1,2-D, 1,2-diacylglycerols.

The Occurrence and Biological Activity of Ferulate-Phytosterol Esters in Com Fiber and Com Fiber Oil. 

Research on maize fiber (Moreau et al. 1996) has shown that oil associated with the fiber fraction is different in composition compared to regular oil obtained from the germ. The fiber oil contains important amounts of ferulate phytosterol esters, free phytosterols, and fatty acid phytosterol esters, which lower serum cholesterol in laboratory animals. The most common class is ferulate phytosterol esters dominated by sitostanol, which is considered more efficient in lowering cholesterol. Phytosterols, such as ergosterol, campesterol, P-sitosterol, and stigmasterol, compete for cholesterol absorption, and therefore are considered hypocholesterolemic and preventive against CVD. According to Raicht et al. (1980) and Fiala et al. (1985) the supplementation of 0.2% P-sitosterol decreases the occurrence of chemically induced colon tumors. 

Phytosterols have been demonstrated as being anti-cancer components in the diet (Awad and Fink 2000). Scientific studies indicate that phytosterols may offer profection against colon, breast and prostate cancers (Vanderhaeghe and Bouic, 2000). The possible mechanisms, as reported by these authors, include the effect of phytosterols on membrane structure and function and on the signal transduction pathways that regulate tumor growth and apoptosis. The rice bran derived phytosterol-cycloartenol-ferulic acid ester on the central nervous system has been studied by Hiraga et al. (1993). 

Hiraga, Y., N. Nakata, H. J in, et al. Effect of the rice bran-derived phytosterol cycloartenol ferulic acid ester on the central nervous system. Arz-neim-Forsch 1993 43(7) 715-721. Mao, X. H., R. P. Xu, S. G. Wang, et al. Simultaneous extraction of oryzanol and yazhouning from crude rice bran oil. Patent-Faming Zhuanli Shenqing Gongkai Shuomingshu—1,067,448 1992 14 pp. 

Feruhc acid esters of phytosterols (steryl ferulates) have been identified in rice, wheat, rye, triticale and barley. The highest amounts of ferulated phytosterols occur in rice. They are also... 

Keywords Plant sterol phytosterol sterol conjugate steryl ferulate gamma-oryzanol steryl glycoside acylated steryl glycoside steryl ester free sterol. 

As the vast majority of human studies on the effects of phytosterols on serum cholesterol levels have been done using free sterols and sterol fatty acid esters, there has been a debate about the efficacy of the other natural sterol conjugates in lowering cholesterol. However, recent studies have demonstrated that other conjugates (ferulic acid... 

Figure 10.1 Examples of structural formulas of phytosterol and sterol conjugates. FS = free sterol alcohol, SE = sterol fatty acid ester, SF = steryl ferulate, SG = steryl glycoside, ASG = acylated steryl glycoside.

Steryl ferulates (SFs) are esters of phytosterols and ferulic acid. Also esters of other phenolic acids, namely p-coumaric acid and caffeic acid,... 

Abbreviations nr—not reported TAG—triacylglycerols FFA—free fatty acids St —phytosterol fatty acyl esters St—free phytosterols FPE—phytosterol ferulate esters tocols-tocopherols and tocotrienols GL—glycolipids PL—phospholipids RBD—refined, bleached, and deodorized oil. 

Abbreviations nr, not reported TAG, triacylglycerols FFA, free fatty acids St E, phytosterol fatty acyl esters St, free phytosterols FPE, phytosterol ferulate esters Tocols, tocopherols and tocotrienols GL, glycolipids PL, phospholipids and RBD, refined, bleached and deodorized oil. 

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