Development of Heat-Stable Cookie Filling : Effect of Emulsifiers on Fat Crystallization

English. Emulsifiers can influence fat crystallization through multiple mechanisms: by promoting or in-hibiting nucleation, modifying polymorphic transitions, or enhancing oil-binding capacity. In collaboration with Palsgaard A/S, this thesis aimed to evaluate the functional impact of selected emulsifiers from their portfolio on the thermal and textural stability of fat-based biscuit cream fillings. The goal was to develop a heat-stable formulation capable of withstanding elevated storage and transport temperatures. Six oil blends were initially screened based on their solid fat content (SFC), texture and feasibil-ity, resulting in the selection of an optimal fat matrix. This base was then modified with five different emulsifiers, applied at three concentrations, to investigate their influence on fat crystal-lization behaviour and cream performance. A variety of analytical techniques, including Nuclear Magnetic Resonance (NMR), Differential Scanning Calorimetry (DSC), rheological analysis, texture analysis along with shelf-life observation was employed to characterize the structural and functional properties of the formulations. The results demonstrated that both emulsifier composition and concentration significantly influ-enced cream firmness, oil retention and spreadability. Crystallizers rich in triglycerides (such as Palsgaard® CrystalPromoter 6117 and Palsgaard® OilBinder /CrystalPromoter 6121) promoted robust crystal network formation and enhanced thermal stability. In contrast, emulsifiers with higher levels of mono- and diglycerides (e.g., Palsgaard® DMG 0091 and Palsgaard® DMG 0298) yielded softer textures but exhibited reduced oil-binding capacity. Overall, Palsgaard® CrystalPromoter 6191 at 0.5% demonstrated the most balanced perfor-mance across key parameters, combining structural integrity, spreadability and oil retention. This supports the conclusion that intermediate concentrations of effective crystallizers offer a promis-ing approach for developing heat-resistant, consumer-acceptable cream fillings.

English. Have you ever opened a pack of sandwich biscuits only to find the cream has melted, leaked out, or worse, clings to your mouth with a dry, crumbly texture? What seems like a simple snack issue is a serious challenge for food scientists and manufacturers, especially in regions where temperatures can rise significantly. In a collaborative project with food innovation company Palsgaard A/S, our research focused on developing cream fillings for biscuits that can endure heat without losing their texture, structure or appeal. At the core of the challenge is fat, the main ingredient in cream fillings, which melts across a range of temperatures. The way fat crystallizes plays a key role in whether the cream remains firm, how it feels in the mouth and how well it holds up on the shelf. Our approach cantered on emulsifiers, which are ingredients that help fats behave more predict-ably. Some emulsifiers speed up fat solidification, others bind oil to prevent separation and some influence the structure of fat crystals. By testing different combinations and concentrations of emulsifiers from Palsgaard, we examined how these additives affected cream firmness, stick-iness, spreadability and oil retention. Our findings showed that emulsifiers don’t all work the same way. For instance, one known as 6191 performed best at moderate and even higher concentrations, producing a cream that stayed firm under heat while remaining smooth and spreadable. Others, such as 6121, formed dense fat networks that could make the cream too hard or brittle, especially in higher amounts. Some emulsifiers, in contrast, made the cream too soft or oily. To understand these effects, we used advanced lab techniques to measure the creams texture under various temperatures and conditions. But the real value of this research lies in its practical application, which is helping producers make biscuits that stay tasty and non-greasy, even in hot climates. In short, our study shows how carefully chosen emulsifiers, at specific concentrations, can fine-tune the texture and heat resistance of cream fillings, offering real solutions for producing bis-cuits that maintain their quality, even when the heat is on.