(609f) Novel Methods for the Improvement of Crystallization in the Food Industry | AIChE

(609f) Novel Methods for the Improvement of Crystallization in the Food Industry


O'Grady, D. - Presenter, METTLER TOLEDO
Redman, T. P., METTLER TOLEDO AutoChem

Lactose is a valuable byproduct of the dairy industry that is isolated from whey permeate in a single crystallization step at an industrial scale. It is commonly used as a food and pharmaceutical additive and is also a component of infant formula where it is necessary to match the composition of human milk.  

While some industry knowledge of the lactose crystallization step has been developed in recent years it remains far from optimized and lactose suppliers face challenges maintaining product quality as they try and reduce costs. In particular, the energy cost per kilo of lactose remains high due to the need to slowly heat and then cool vast quantities of whey permeate. Efforts to speed up the crystallization process, reducing the batch cycle time, often negatively impact product quality and consistency. This in turn poses difficulties as demand for uniform lactose increases in the highly regulated food and pharmaceutical markets

These competing cost and quality challenges mean new approaches to optimize lactose crystallization are being investigated. Of particular interest to plant managers are methods to monitor lactose crystals in the crystallizer as the nucleate, grow and aggregate. A traditional approach would be to take samples of the crystals and analyze them offline using a benchtop particle size analyzer such as laser diffraction or a sieve. However, such an approach has failed to gain acceptance due to the extended time delay between taking the sample and receiving the results and the propensity for crystals to break, dissolve or nucleate during sampling and sample preparation.

In this presentation novel methods are presented that allow lactose crystal, size shape and count to be measured in situ without the need for sampling using the probe-based ParticleTrack technology. By directly linking process parameters to changes in crystal size and count over time it will be shown that improved lactose crystallization processes can be implemented resulting in higher quality and reduced cost.