Functional properties and chemical composition of fractionated brown and yellow linseed meal (Linum usitatissimum L.)

Considering its high content of protein and dietary fiber, linseed meal is a remarkable source for food ingredient and food additive production. In this study, brown and yellow linseed meal (Linum usitatissimum L.) were fractionated via pH control, to obtain five linseed meal fractions rich in protein and fiber. The fractions were characterized by measuring functional properties, proximate and carbohydrate composition, and lignan contents. Acid soluble protein fractions were characterized by lower emulsification capacities and foaming activities in comparison to a commercial soy protein isolate. Alkaline soluble protein fractions showed emulsification activities comparable to whole egg and relatively high contents of secoisolariciresinol diglucoside (SDG) of 110 mg/g DM and 56.2 mg/g DM, respectively. The good emulsification and foaming activities, as well as the enriched concentration of SDG and therefore high nutritional value, make especially the alkaline soluble protein fraction highly interesting for food ingredient production.