Influence of Jet-Cooking Corn Bran on Its Antioxidant Activities, Phenolic Contents and Viscoelastic Properties

Corn bran was subjected to high-shear and jet-cooking with or without alkaline treatment. The highest antioxidant activity was found in the soluble solids from jet-cooked corn bran without alkaline treatment. Jet-cooking under alkaline conditions resulted in a soluble fraction having the highest phenolic content but without increasing antioxidant activity. Phenolic contents of soluble solids were significantly higher than the insoluble solids. A colorimetric method using spectrophotometer was suitable to determine total phenolic content, whereas LC-ESI-MS technology was used for identifying important individual phenolic acids, namely caffeic, coumaric and ferulic acid. The insoluble solids from alkaline treatment had the highest water holding capacity and interesting viscoelastic properties. These results suggested that jet-cooking corn bran may be a useful processing procedure for creating phytochemical and functional products.