153 Natural polyphenolic antioxidant alternatives for extruded oat cereals.

K. V. Viscidi, M. E. CAMIRE, M. P. Dougherty (1), and J. Briggs (2). (1) University of Maine, Dept. of Food Science and Nutrition, Orono, ME 04469; (2) Natick Soldier Center, Natick, MA 01760.

Oats have relatively high lipid and lipase levels that make oats more susceptible to lipid oxidation and subsequent undesirable rancid flavors. Expanded extruded products are also more susceptible to oxidation. Five polyphenolic compounds – benzoin, catechin, chlorogenic acid, ferulic acid and quercetin – were added at 1000 ppm to rolled oats plus 10% sugar prior to twin-screw extrusion; quercetin was also tested at levels of 500 and 1500 ppm. Extruded oat cereals were stored at 35 C. These cereals were analyzed every 4 weeks for peroxide values and conjugated dienes by spectrometry and hexanal concentration by GC. A sensory panel rated rancid flavors. Phenolic compounds did not affect diametric expansion, but quercetin produced a slight yellow color. Hexanal and conjugated diene concentrations continued to rise through at least 12 weeks of storage whereas peroxide values seem to level between 4 and 8 weeks. After eight weeks, benzoin appeared to be the most effective and chlorogenic acid least effective of the antioxidant compounds, but results varied. Natural polyphenols can reduce lipid oxidation without impairing other quality attributes.