Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: March 13, 2007
Publication Date: November 1, 2007
Citation: Inglett, G.E., Stevenson, D.G., Lee, S. 2007. High-fibre products: converting oats to high-fibre products for use in functional foods. In: Hamaker, B.R., editor. Technology of Functional Cereal Products. Cambridge, U.K. Woodhead Publishing Ltd. p. 476-494. Technical Abstract: A new generation of soluble beta-glucan product, called Nutrim-OB (OB, oat bran), was developed that qualified for a FDA health claim. Nutrim-OB was prepared by heat-shearing oat flour or bran aqueous slurry in series of treatments that solubilises oat beta-glucans but maintains basic bran composition. Slurry viscosity is reduced by >90%, rendering it flowable through sieve pores (40 micrometers to 400 micrometers) or allowing separation of insoluble crude fibre particles by centrifugation and subsequent drum-drying provides high yields. Contrary to reducing biological activity, processing engenders beta-glucans more biologically active and maintains similar antioxidant properties to that of the starting out material. Nutrim-OB has unusually high viscosity at 5 to 15% solids and ambient temperatures and its viscosities are many times higher than Oatrim. Nutrim-OB produced from defatted oat fines, flour or bran exhibited shear-thinning throughout shear rate range studied during a thixotropic loop experiment. High-sugar ratio cake batters formulated with Nutrim-OB had higher viscosity and unaltered shear-thinning compared with cake batters without hydrocolloids. Pasting properties of oat bran concentrate and Nutrim-OB without and with lipid extraction by supercritical carbon dioxide have been studied. Three new oat beta-glucan hydrocolloids (designated as C-trim20, C-trim30, and C-trim50) obtained through thermal-shearing processing have been developed that also have potential use as functional food ingredients. C-trim products differ from Nutrim-OB by having an additional centrifugation step prior to jet-cooking that eliminates a higher proportion of starch, and centrifugation and sieving steps after jet-cooking determine the final beta-glucan concentration.