Effect of corn milling practices on aleurone layer cells and their unique phytosterols

ABSTRACT Coarse and fine fiber fractions obtained from the corn wet-milling processes, with and without steeping chemicals (SO2 and lactic acid), were evaluated microscopically for structure and analytically for recovery of phytosterol compounds from the fiber oil. Microscopic results showed that wet milling, with and without chemicals during steeping, changed the line of fracture between pericarp and endosperm and therefore affected the recovery of the aleurone layer in coarse (pericarp) and fine (endosperm cellular structure) fiber. Analytical results showed that most of the phytosterols and mainly phytostanols in corn fiber are contributed by the aleurone layer. Hand-dissection studies were performed to separate the two layers that comprise the wet-milled coarse fiber, the aleurone, and pericarp layer. Analyses revealed that the aleurone contained 8× more phytosterols than the pericarp.