CO2 gas hydrate as an innovative leavening agent for baked goods

In the presented research, the use and technical realization of CO2 gas hydrate (GH) as a novel baking agent is investigated. GH are ice-like structures where one mole of hydrate typically consists of about 85% water and 15% gas. Hydrates were formed in a lab-scale 1.1 L stirred tank reactor at 1-2 °C and 3.5 MPa, and transferred into a temperature-controlled, gas-tight measuring cell. The leavening effect of gas hydrates was assessed by measuring the CO2 release rates. Storage stability at -20 to 0 °C and stability above 0 °C were investigated experimentally and a coupled thermodynamic and kinetic decay model implemented. At -10 °C, gas release was highest in the first minutes and stopped completely after 5 days. After 21 days storage at -10 °C, the GH still contained 20 % of the initial gas content. Above 0 °C, dissociation rates were highly temperature dependent, and half value times ranged from 30 min (3 °C) to 4 min (20 - 30 °C). Above 10 °C, ambient temperature had only a minor effect on the dissociation rates. Results from the kinetic decay model, applied for a 21 mm particle, showed similar dissociation behavior as a particle from experiments. Applying the model for a 3 mm particle, showed full dissociation after approximately 15 min. Stability and baking tests showed that CO2 hydrate is in principle suitable as a leavening agent. However, GH production still needs to be optimized and recipes for GH application require further development.