PhD defence

Eutectic Freeze Crystallization of Lactose; A novel separation technology for food systems at sub-zero temperatures

Promotor A (Albert) van der Padt
External copromotor Dr Doekle Yntema
Organisation Wageningen University, Food Process Engineering

Fri 2 June 2023 13:30 to 15:00

Venue Wetsus, Leeuwarden
Room Externe zaal 1


Eutectic freeze crystallization (EFC) is a separation method that uses sub-zero temperatures. By partially freezing a solution, a solution can be concentrated to the point where the solute also begins to crystallize: the eutectic point. Using this point, a solution can be converted into ice and crystals. This technique is already applied to brine solutions however it had never been tried for food systems. The advantage of EFC for food systems is its low energy consumption and low temperature, biological activity is low and heat-sensitive components are not decomposed.

In this study, EFC was applied to lactose, an important raw material for baby food production and pharmaceuticals. It was shown that lactose could be extracted at temperatures below zero from both a pure system and a residual stream from lactose production. In a pilot-scale test, it was shown that ice and lactose could be extracted simultaneously. Energy savings of 30-80% were possible compared to a conventional evaporation process