Hybrid variability and effect of growth location on corn fiber yields and corn fiber oil composition

The variability in commercial corn hybrids for corn fiber yields, amounts of extractable oil, and levels of individual and total phytosterol components in corn fiber oil was determined. Also, the effect of growth location on fiber yields, fiber oil content, and the levels of individual and total phytosterol compounds was determined. Significant variation was observed in the commercial hybrids for fiber yield (13.2-16.6%) and fiber oil yield (0.9-2.4%). No significant correlation was observed between fiber and oil yields. Significant variations in the commercial corn hybrids were also observed in the individual phytosterol compounds in corn fiber oil: 2.9-9.2% for ferulate phytosterol esters (FPE); 1.9-4.3% for free phytosterols (St); and 6.5-9.5% for phytosterol fatty acyl esters (St:E). Positive correlations were observed among the three phytosterol compounds in the corn fiber oil (R = 0.75 for FPE and St:E; 0.48 for St:E and St; and 0.68 for FPE and St). The effect of location on dependent variables was also significant. The same hybrids grown at different locations showed a variation (range) of 4.0-17.5% for FPE, 4.9-12.2% for St:E, and 1.95-4.45% for St. Relative ranking of hybrids with respect to phytosterol composition was consistent for almost all of the growth locations.