Principles and applications of freeze-concentration and freeze-drying

WELTI CHANES, J; BERMUDEZ, D; VALDEZ FRAGOSO, A; MUJICA PAZ, H; ALZAMORA, STELLA MARIS

Handbook of Food Science, Technology and Engineering, Vol. 3 - 116

CRC Press / Taylor & Francis

Lugar: Boca Raton; Año: 2006; p. 1 - 9

In freeze-concentration and freeze-drying processes water is first frozen in the material. Ice is removed by  mechanical means during freeze-concentration leaving a concentrated liquid, while ice is removed by sublimation in freeze-drying yielding a dried material. The removal of water by these methods would yield high quality products, but in both processes it is a very expensive operation due to the high consumption of energy. Knowledge of the theoretical principles behind these processes is necessary for minimization of detrimental changes, operating strategies, or optimization purposes. Thus, the fundamental aspects of freeze-concentration and freeze-drying are presented in this chapter with special emphasis on food preservation processes.