Addition of value to low B-glucan oat fraction

Abstract

Different methods are available for obtaining oat fractions with elevated soluble fibre content. Separation of flour particles based on their size and density gives fractions with maximum around 20 % of ?-glucan, whereas higher B-glucan contents can be obtained via various extraction processes. Any of these approaches yields vast amounts of endosperm-rich low B-glucan flour as a side product. The addition of extra value into this side fraction would have a huge impact on the feasibility of whole oat fractionation process. The composition of low ?-glucan oat flour provides no nutritional superiority over other cereal products. Instead, due to high lipid content it has some technological limitations such as a high tendency to stick in elevators, barrels and transporters. Also, when such flour is mixed in water, it will readily form large clumps, which make it difficult to form homogeneous mixtures. Due to these limitations, oat endosperm flour is typically used in low value products such as animal feed. The purpose of our work was to introduce new technological functionality into low B-glucan oat flour and simultaneously overcome negative aspects associated to this fraction. This was achieved by hydrothermal treatment yielding partially damaged starch (Kiiliäinen et al, 2004). Several desired changes were observed due to this treatment and the hydrothermally treated flour hydrates easily already at room temperature. Concurrently with the starch damage a relocalisation of oat lipids was also noticed, resulting in re-duced extractability of the lipids. These changes provide the basics for the use of hydrothermally treated oat flour in baking and ready made food applications where it can offer a cost effective replacement for other water binding agents such as pre-gelatinized starch products. Kiiliäinen, K. Lehtinen, P., Mikola, M. and Laakso, S. 2004. Journal of Cereal Science, to be submitted 2004.