Effect of Harvest Moisture Content and Ambient Air Drying on Maize Fiber Oil Yield and its Phytosterol Composition

In the conventional maize wet-milling process, a maize kernel is separated into its individual components. Starch (which constitutes 60–70% of the maize kernel) is the prime product. Other components of the maize kernel, which includes germ (oil), protein and the fiber, are recovered as coproducts. Presently, maize fiber is mixed with heavy steepwater and sometimes with germ meal to produce maize gluten feed which is one of the lowest valued coproducts in a maize wet milling facility. Recent research on maize fiber has shown that it can be used for extraction of maize fiber oil which has three different classes of phytosterol compounds: ferulate phytosterol esters (FPE), free phytosterols (St) and phytosterol fatty acyl esters (St:E)) [1]. In numerous clinical studies phytosterol compounds have been shown to lower serum cholesterol levels and, therefore, have found applications as nutraceutical compounds. Maize fiber oil is different from maize germ oil because maize germ oil contains much lower levels of phytosterols and negligible amounts of FPE.