7. Conclusion

The manufacture of frozen desserts has undergone considerable technological change over the last thirty years, with a whole series of innovations designed to improve the sensory quality of finished products.

While we now know a great deal about ice cream as a complex physico-chemical edifice, thanks to current techniques for observing and modeling its microstructure, the physical mechanisms at work in freezers and other extruders remain obscure. The key elements in the freezer and extruder are: the size of the pure water ice crystals, the size of the air bubbles and the state of the fat fraction responsible for stabilizing the expanded emulsion. The key parameters mainly concern temperature, pressure and the quantity of air injected (expansion efficiency), as well as the design of the turbines, beaters or screws, depending on the equipment used. Understanding through...