Effet des procédés de fractionnement sur la composition et quelques propriétés nutritionnelles des produits céréaliers

Wheat bioactive compounds (fibres, minerals, vitamins, antioxidants) are concentrated in grain outer layers, which constitute the bran fraction obtained after the milling process leading to the white flour. In order to improve the health value of the flours, whole grains can be processed or alternatively, bran fractions can be added to white flours. In the bran, bio-actives compounds are poorly bio-accessible as they are trapped in resistant cell-wall. Dry fractionation of wheat bran takes advantage from differences in compositional and mechanical properties between grain tissues. Both ultrafine milling and electrostatic separation can be used to prepare bran fractions with different degrees of micronization and/or enriched in compounds of interest. In vitro digestion studies of bran-enriched breads have shown that the bio-accessibility of phenolic acids and minerals improves with decreasing particle size and also with increasing concentration of micronized aleurone material.