Caking of lactose: A critical review
Résumé
Background: Caking is a recurrent problem in various industries, whether it occurs during the production,
storage or transport of powders. Caked powder results in longer processing times and decreased
product quality, leading to significant economic loss. Several caking mechanisms have been described in
the literature. However, they are often difficult to take into account in an industrial context, given the
many parameters which influence the overall caking phenomenon.
Scope and approach: This review describes the three relevant caking mechanisms for food powders in
general. Focussing on predominantly crystalline lactose powder, we discuss how each of these mechanisms
can explain caking and be prevented in the industrial context. The second part of this paper
presents a critical review of the methods used to characterise caking to date.
Key findings and conclusions: The presence of amorphous material and other impurities must be assessed
in crystalline lactose powders, as they can trigger amorphous and humidity caking. Particle size distribution
is another key parameter requiring control as it can encourage caking through enhancement of
particle interactions. In general, preventing caking in food powders can only be achieved by a thorough
understanding of the production process and storage conditions. Moreover, the characterisation of caking
remains a challenge as most methods published in the literature do not fit the needs of the food industry.
The real demand is for a reliable method to predict caking which would be rapid and easy enough to be
applied to each batch for quality control.