Formation, characterization, and application of heteroaggregates obtained from oppositely charged colloids

Obesity and overweight increasingly pose a severe risk to public health worldwide. Therefore, the food industry aims at developing calorie-reduced, highly structured foods with taste and mouthfeel similar to full-fat foods. Moreover, todays' food formulation approaches focus on retaining a certain amount of fat instead of its complete removal, not only because fat is an important carrier for lipophilic compounds, but also because the consumption of fat is closely linked to satiety. Therefore, fat-reduced foods need to be structured such that they widely mimic the texture and appearance of full-fat foods. One novel lipid structuring approach at the forefront of current research is heteroaggregation, whereby mixed aggregates are formed through combinations of at least two different but attracting particle types. To date, however, little is known about the principles of formation, their physico-chemical properties, and their applicability in foods. The goal of this thesis was therefore to address this existing gap in the knowledge base. In particular, the formation of heteroaggregates from food emulsions was investigated, mimicking the rheological properties of food emulsions with higher fat contents. In brief, mechanistic insights into the formation and stabilization of heteroaggregates using food-grade components were obtained in this doctoral thesis that may in the future prove to be useful in the formulation of newly structured food systems. Furthermore, they may serve as new carrier systems to deliver multiple lipophilic components encapsulated in different but proximate compartments within a single bulk phase.