Edible meta-materials

Oleogels are lipid-based materials containing >85% liquid oil but resemble the appearance and texture of solid fats, like coconut and palm oils. They have been developed with the aim to reduce the deleterious health effects of saturated fat overconsumption. Unfortunately, they still have structural and storage stability problems that hinder their applicability in food products.

To tackle these problems, we:

1) developed an open surface, batch treatment chamber featuring planar ultrasonic transducers able to generate 2D standing fields. The standing field is then used to arrange gelator crystals during their formation with the aim to modulate the mechanical/rheological properties and stability of the resulting oleogels. We are now developing more sophisticated chambers to develop 3D ultrasonic standing fields and continuous process.

2) studied two solutions to tackle the low tolerance of oleogels to mixing and large shear forces such as those experienced during lamination. Here we developed (i) a composite oleogel using water-insoluble particles and (ii) a process to obtain an oleogel using ultrasonically assisted electrospun nano- and microfibers. The resulting oleogel were able to withstand mixing and were used to produce croissants. We are testing different food grade materials for producing nano- and microfibers.

3) designed and developed the first-of-its-kind engineered oleogel containing active ingredients that reduce caloric content and induces satiety so that this oleogel can reduce the amount of food consumed over time. We demonstrated this approach in in vitro digestion systems and we are going to test the system in animal tests. We are currently expanding the strategies to tailor oleogel digestibility.

Highlights:

1. Bhattarai, M., Penttilä, P., Barba, L., Macias-Rodriguez, B., Hietala, S., Mikkonen, K. S., & Valoppi, F. (2022). Size-dependent filling effect of crystalline celluloses in structural engineering of composite oleogels. LWT, 160, 113331

2. Valoppi, F., Salmi, A., Ratilainen, M., Barba, L., Puranen, T., Tommiska, O., Helander, P., Heikkilä, J., & Haeggström, E. (2020). Controlling oleogel crystallization using ultrasonic standing waves. Scientific Reports, 10, 14448

3. Lassila, P., Valoppi, F., Tommiska, O., Hyvönen, J., Holmström, A., Hietala, S., Salmi, A., & Haeggström, E. (2022). Practical scale modification of oleogels by ultrasonic standing waves. Ultrasonics Sonochemistry, 85, 105970

4. Sabet, S., Kirjoranta, S., Lampi, A. M., Lehtonen, M., Pulkkinen, E., & Valoppi, F. (2022). Addressing criticalities in the INFOGEST static in vitro digestion protocol for oleogel analysis. Food Research International, 160, 111633