A way to enrich cereal products with bioactive compounds is to manufacture flours with high levels of selected parts of the outer layers. To remove the very outermost layers, partial debranning of grains in using friction (peeling) or abrasion (pearling), was combined with milling (grinding and sieving) to produce flours with tailored tissue composition and thus controlled in content of bioactive compounds, as monitored by the marker methodology. Flours made from peeled grains, peeled and pearled grains and grains with removed outermost layer and crease parts exhibited high contents of bioactive compounds and improved nutritional effects as compared to common flours.
Another way of exploiting cereal potential is to use the miller's bran, a by-product of the milling industry, as a source of healthy ingredients. Careful limited grinding and sieving of the bran allowed to prepare a concentrate of aleurone cells and aleurone layer, where most of the bioactive compounds of the grain are located. Further purification by electrostatic classification yielded practically pure aleurone cells that exhibited excellent nutritional properties.
Another approach used ultrafine grinding of the bran in ambient or cryogenic conditions, to provoke a full dissociation of the material at a sub-cellular level. This resulted in an increase in bioactive compounds bioaccessibility. Classification of the fine particles in using a electrostatic separator made it possible to prepare fractions of very contrasted compositions in starting from bran. One of these ingredients, concentrated in fine aleurone particles, showed a good accessibility of anti-oxidants and mineral compared to bran and untreated aleurone. These techn
|Contact: Xavier Rouau|
VTT Technical Research Centre of Finland