Hydrophobic/hydrophilic surface activity III: interactions with other micro- and macromolecules

Covalent and noncovalent interactions of proteins with micro- and macromolecules, such as phytochemicals (e.g., phenolic compounds or flavor molecules), can lead to a multitude of effects on ingredient and product properties. Among these is a change in the hydrophilic/hydrophobic balance of proteins and partial unfolding, which in most cases leads to improved emulsifying properties of plant proteins. Currently underutilized by-product streams, such as sunflower or rapeseed press cake, are often high in bioactive micro- and macromolecules. While the common approach is to remove these bioactive substances to obtain a protein isolate, understanding and controlling interactions between phytochemicals and proteins could open new routes for functionalizing proteins. Thus it might not be necessary to remove these ingredients completely, and they may even be used to enhance the functionality of the by-product streams.