Submitted to: Cereal Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/1/2000
Publication Date: 3/1/2000
Citation: Interpretive Summary: Recent research on corn fiber has shown that an oil can be extracted from the fiber fraction and this oil is very different in composition than commercial corn (germ) oil. This fiber oil contains high levels of three types of phytosterols. Phytosterols have been shown to lower the amount of serum cholesterol in blood and, therefore, can potentially be used as nutraceutical products. Preliminary experiments have indicated that there is considerable variability within corn hybrids in the amount of corn fiber oil and level of these unique compounds. Hybrid variability in corn affects its processing and results in substantial economics loss to the corn processing industry. To minimize the processing fluctuations and the economic loss, selective processing of hybrids is recommended. To determine if selective processing of corn hybrids will be required for recovery of fiber oil and its cholesterol lowering compounds, the extent of fvariability in hybrids needs to be identified. In this study we evaluated the variability in several commercial corn hybrids from three seed corn companies. The results showed significant variation in the corn hybrids for corn fiber yields, amount of oil and levels of cholesterol lowering compounds. The results suggest that careful selection of hybrids may help to optimize the recovery of each individual cholesterol lowering compound from corn fiber.
Technical Abstract: 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 were 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 the fiber yields (13.2-16.6%) and fiber oil content (0.9-2.4%). No correlation was observed between the fiber yields and the oil content. 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 or FPE, 1.9-4.3% for free phytosterols or St, and 6.5-9.6% for phytosterol fatty acyl esters or St:E). Positive correlations were observed among the three phytosterol compounds in the corn fiber oil (coefficient of determination=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 found to be 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. Differences in sensitivity (variation in phytosterol composition) of hybrids to growth location were also found to be significant. Relative ranking of hybrids with respect to phytosterol composition was consistent for almost all of the growth locations.