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United States Department of Agriculture

Agricultural Research Service

Title: Phenolic Content and Antioxidant Activity of Supercritical Carbon Dioxide Treated and Air-Classified Oat Bran Concentrate Microwave-Irradiated in Solvents at Varying Temperatures

item Stevenson, David
item Biswas, Atanu
item Eller, Fred
item Evangelista, Roque
item Inglett, George

Submitted to: American Association of Cereal Chemists Meetings
Publication Type: Abstract Only
Publication Acceptance Date: October 8, 2007
Publication Date: October 8, 2007
Citation: Stevenson, D.G., Biswas, A., Eller, F.J., Evangelista, R.L., Inglett, G.E. 2007. Phenolic content and antioxidant activity of supercritical carbon dioxide treated and air-classified oat bran concentrate microwave-irradiated in solvents at varying temperatures. American Association of Cereal Chemists Meetings. 52(4):A66.

Technical Abstract: In addition to health-beneficial beta-glucans, oats contain phenolic compounds (PC) and other antioxidant activity (AA). We investigated processing technologies to produce oat ingredients with concentrated levels of PC and AA. Oat bran concentrate (OBC) had lipids removed by supercritical carbon dioxide extraction (SCD), then air-classified into five fractions (< 15, 15-18, 18-24, 24-30 and > 30 micrometer particle diameter), dispersed in water, 50% or 100% ethanol and microwave-irradiated for 10 min at 50, 100 or 150<sup>o</sup>C. OBC without SCD and microwave irradiation was also extracted at 22<sup>o</sup>C. Most effective temperature during microwave irradiation for maximizing extraction of PC and AA was 150<sup>o</sup>C. SCD-treated OBC in 50% ethanol and microwave-irradiated at 150<sup>o</sup>C extracted greatest amount of PC and AA. OBC extracted in water or 50% ethanol at 22<sup<o>/sup>C without microwave irradiation had similar PC and AA than OBC microwave-irradiated at 150<sup>o</sup>C, but much higher levels were observed for latter heat treatment using 100% ethanol. Air-classification showed potential to enhance PC and AA. This study demonstrated that enhancement in concentration of PC and AA of OBC can be achieved by microwave-irradiating at 150<sup<o>/sup>C for 10 min in 50% ethanol, and SCD slightly decrease PC and AA obtained while utilizing coarse fractions obtained from air-classification may help enrichment of PC and AA.

Last Modified: 4/22/2015
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