What is Thermal Stability?
In food, thermal stability refers to the tendency of a food product to maintain its structure and taste during high-temperature applications (such as baking, etc.).
High temperatures generally irreversibly alter the structure of food products. With some specialized stabilizer ingredients and techniques available in today’s technology, the form of food products can be partially preserved under high temperatures. Specifically, fillings that can maintain their structure during baking have been developed, especially in the pastry and bakery sectors.
Fillings
Fillings are essential inputs in the pastry and bakery sector. Besides diversifying and enhancing flavors, they add unique qualities to the final product. They are used in many products like cookies, cakes, pastries, croissants, etc.
Fillings can generally be categorized into two types:
Water-Based Fillings (Cream-type, fruit-based, ganache sauce, etc.)
Fat-Based Fillings (Hazelnut creams, etc.)
Fillings interact with the main component of the final product, the dough. Hence, the chosen filling must be compatible with the characteristics of both the final product and the dough (water activity, viscosity, shelf life, etc.).
For the best outcome, fillings should maintain their structure and taste during storage, shelf life, and baking.
Importance of Thermal Stability in Fillings
In some applications, fillings need to be applied inside or on top of the product before the baking process. The thermal stability property ensures that the structure of the filling used in pre-bake applications is preserved. Thanks to this property, the filling tends to maintain its structure throughout the baking process.
A filling without thermal stability would boil or melt during baking. This would lead to the deterioration of the filling’s structure and negatively impact the final product’s quality. Imagine applying a non-thermally stable filling inside cookie dough and then baking it. In this case, you might encounter the following issues:
- The filling can’t hold its form and will spill out, pressing against the dough’s edges.
- Filling that boils within the dough won’t regain its original form after baking, resulting in voids within the product.
- Due to the high temperature, the filling’s fat will melt first, followed by burning on the surface. Fillings with thermal stability, on the other hand, aren’t negatively affected by high temperatures during pre-bake applications and preserve their form and flavor after baking. Nowadays, thermal stable fillings are widely utilized, especially in cookie applications.