The emulsifying performance of mildly derived mixtures from sunflower seeds

Sustainability driven production of food ingredients is in the center of discussion the past years, with plants being a promising source, since they are widely available and have smaller environmental impact compared to animals. However, plant material consists of a sturdy configuration comprising many components, like proteins, which cannot be readily liberated. Thus, downstream processing of plants often involves intensive physicochemical and thermal processing, which might be accompanied by alteration of protein properties, like emulsification ability. Here, the aim was to investigate the emulsification ability of the native mixtures derived from sunflower seeds, obtained via simple separation steps and link their properties with their molecular composition. The investigated molecular mixtures were the cold-pressed sunflower cake, a protein-based and a fibre-based mixture. It was demonstrated that the residual oil in both the Sf cake and the protein-based mixture was present in the form of naturally emulsified oil droplets, so-called oil bodies. Oil bodies did not have a notable impact on the interfacial activity of the samples in contrast with the destabilization effect of polysaccharides. Despite their complex composition all mixtures could efficiently stabilize oil/water interfaces, showing similar properties compared to isolated proteins. This is an intriguing bottom line regarding the necessity for using pure emulsifiers. The findings prove that molecular mixtures which contain even minor amounts of proteins, can be used as ingredients for efficient emulsion stabilization.