What are oleogels? How do they work? How are they revolutionizing the food industry?
Oleogels are gelled systems made with an oil phase entrap in a gel-like structure formed by a three dimensional network made from proteins or hydrocolloids, these ingredients are commonly called oleogelators or just gelatores. They are currently a promising alternative to traditional solid fats that are high in saturated and trans fats; both associated with several health issues.
Current health concerns have been responsible for the development of novel alternatives health products that could reduce or diminish the negative health effects of solid fats, and thus the development of this novel food products based on unsaturated fatty acids processing from vegetable oil such as olive oil and avocado oil.
Oleogels are formulated from a base network made from a gelling agent or oleogelators. Its production requires the use of oleogelators in low concentration that are able to intrap the oil in their three dimensional structure and thus impart a solid-like structure to the oil. The main challenge scientists confront in the development of this product is associated with the functional properties required for the production of several food products, thus it’s of the utmost importance the determination of the rheological and texturizing properties of the oleogel, as well as their oil binding and stabilizing properties.
Potential Uses
A wide variety of potential uses can be applied for this alternative fat mimetics or substitutes, among the most relevant ones are: meat products, margarine, cream, baked goods, spreads, ice creams, cakes, cookies and cream cheese.
Oleogels provide a better lipid profile than their traditional fats counterparts, due to lower levels of saturated fatty acids and the absence of trans fats; as well as the higher degree of mono and polyunsaturated fatty acids. They can also help improve the formulated food product by reducing oil migration, acting as a replacement of oil binder or as a partial replacement of palm oil, controlling volatile release, and decreasing oil absorption.
Oil continuous phase or water continuous phase
Emulsions have a continuous and a dispersed phase, both water or oil can be in either phase, depending on the type of emulsion water or oil will be present as small droplets in a continuous phase or be the continuous phase where the small droplets are entrap. Emulsions are the product of the stabilization of two immiscible substances due to their polar or nonpolar character; they are accomplished by the use of emulsifiers and mechanical forces commonly generated by high speed blenders, colloidal mills and/or high pressure homogenizers.
Phase structuring
Structuring of the continuous phase can happen through three mechanisms: pickering (stabilization with solid particles), three dimensional network and a combination of both.
The type of mechanism applied to the formulation of the emulsion and gelator concentration; two states of emulsions can be obtained: solid or semi solid, this type of emulsions are fairly stable and are able to achieve a kinetic stability.
Oil in water (O/W) emulsions are stabilized by electrostatic and steric repulsions,while water in oil (W/O) emulsions are commonly stabilized by steric repulsion due to the low electrical conductivity of the continuous phase.
Conclusion
Oleogels present an interesting opportunity for food scientists around the globe, as a potential fat substitute or fat mimetic for products high on saturated and trans fats by providing the required functional properties while maintaining their beneficial health properties.
References
- Bascuas, S., Hernando, I., Moraga, G., & Quiles, A. (2020). Structure and stability of edible oleogels prepared with different unsaturated oils and hydrocolloids. International Journal of Food Science & Technology, 55(4), 1458-1467.
- Stortz, T. A., Zetzl, A. K., Barbut, S., Cattaruzza, A., & Marangoni, A. G. (2012). Edible oleogels in food products to help maximize health benefits and improve nutritional profiles. Lipid Technology, 24(7), 151-154.
- Patel, A. R., Cludts, N., Bin Sintang, M. D., Lewille, B., Lesaffer, A., & Dewettinck, K. (2014). Polysaccharide‐based oleogels prepared with an emulsion‐templated approach. ChemPhysChem, 15(16), 3435-3439.
- Silva, T. J., Barrera‐Arellano, D., & Ribeiro, A. P. B. (2021). Oleogel‐based emulsions: Concepts, structuring agents, and applications in food. Journal of Food Science, 86(7), 2785-2801.
