Functional properties of linseed meal fractions

Brown linseed (Linum ustatissimum) is pressed to produce oil, and the remaining linseed meal is rich in protein and soluble dietary fiber. To utilize the derivatives of linseed meal as food ingredients or additives, linseed meal was fractionated by controlling pH on a pilot-plant scale. Chemical composition, functional properties and health-related bioactivities, such as angiotensin-converting enzyme (ACE) inhibition and antioxidant activities, of the fractions were then analyzed. The alkaline soluble protein had the highest content of secoisolariciresinol diglucoside (SDG) and showed good emulsification activity, comparable to that of whole egg. The acid-soluble fraction showed the highest viscosity. ACE inhibition, antioxidant activities, and bile acid binding activity were observed in the soluble dietary fiber fraction. There was no correlation between SDG content and bioactivities. These findings indicate that the acid-soluble fraction is useful as a food ingredient to increase viscosity, while the soluble dietary fiber fraction has health-related features.