Comparison of yield and composition of oil extracted from corn fiber and corn bran

We recently reported that corn fiber oil contains high levels of three pote ntial cholesterol-lowering phytosterol components: ferulate-phytosterol est ers (FPE) (3-6 wt%), free phytosterols (1-2 wt%), and phytosterol-fatty acy l esters (7-9 wt%). A previous study also indicated that corn bran oil cont ained less phytosterol components than corn fiber oil. The current study wa s undertaken to attempt to confirm this preliminary observation using more defined conditions. Accordingly, oil was extracted from corn fiber and corn bran prepared under controlled laboratory conditions, using the same sampl e of corn hybrid kernels for each, and using recognized bench-scale wet-mil ling, and dry-milling procedures, respectively. After extraction, the chemi cal composition of the phytosterol components in the oil were measured. Thi s study confirmed our previous observation-that FPE levels were higher in c orn fiber oil than in corn bran oil. During industrial wet-milling, almost all of the FPE are recovered in the fiber fraction (which contains both fin e and coarse fiber). During laboratory-scale wet-milling, approximate to 60 -70% of the FPE are recovered in the coarse fiber (pericarp) and 30-40% are recovered in the fine fiber. During laboratory-scale dry-milling, <20% of the FPE are recovered in the bran (pericarp), and the rest in the grits. Th e recoveries of the other two phytosterol components (free phytosterols and phytosterol-fatty acyl esters) revealed a more complex distribution, with significant levels found in several of the dry- and wet-milled products.