Avenanthramides in oats: A new method of producing whole oats and oat ingredients with greatly elevated avenanthramide levels

© Copyright 2010 AACC International.
Published January 2010.

F. Collins. Agric & Agri-Food Canada

Collins, F. W. 2010. Avenanthramides in oats: A new method of producing whole oats and oat ingredients with greatly elevated avenanthramide levels. Online. AACC International Cereal Science Knowledge Database

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Avenanthramides, of which over 35 distinct components have been found to date, represent the major readily-bioavailable, soluble phenolics present in the oat kernel These hydroxycinnamoyl alkaloids are found only in oats and have been shown to not only act as antioxidants but also to inhibit the pro-inflammatory processes associated with atherosclerotic disease progression. Based on recent in vivo pharmacokinetic results in humans and in vitro human vascular cell culture models, effective concentrations of avenanthramides required to influence vascular antioxidant status and the inflammatory response can be provisionally projected. Threshold response levels (approximately 30 to 60 mg from a dietary source delivery system such as a 50 g serving of oat bran) would require an oat product with at least 600 to 1,200 ppm total avenanthramides. This is a significantly higher concentration range than those currently recorded for existing oat varieties or existing whole grain oat products. Recently a process has been found that significantly increases the levels of avenanthramides in native oat kernels. Levels ranging from about 900 to 2,000 ppm in the whole groat, representing an enrichment factor of about 25- to 40-fold have been achieved by this process, without significantly altering the milling quality of the product. The process involves the concept of “false malting” wherein selected or pre-treated grain is conventionally malted but does not germinate. The selected oats refer to “dormant oat” varieties, i.e. varieties exhibiting secondary dormancy and preferably hulless, while non-dormant varieties can be made dormant using a simple dry heat process. In-depth HPLC analyses of avenanthramides from oats treated by this patent-pending process show little if any qualitative differences relative to untreated oats. Abrasion bran fractions show levels as high as 3,500 ppm total avenanthramides.