Particle morphology and powder properties during spray drying of maltodextrin and whey protein mixtures

E.M Both,R.M Boom,M.A.I Schutyser

doi:10.1016/j.powtec.2020.01.001

Abstract

Application behavior of spray dried powders such as reconstitution behavior and flowability is indirectly influenced by powder particle morphology. We here investigated the influence of the drying conditions and composition for whey protein (WP), maltodextrin (MD) and their mixtures on particle morphology during pilot-scale spray drying. Even though all powders showed a variety of morphologies, MD powders contained more wrinkled particles and had high bulk density, whereas pure WP powders contained more hollow particles. Mixture powders (75:25 WP:MD) show more hollow particles with increasing inlet temperature, with a lower bulk density. The observed morphologies for different formulations corresponded roughly to previous observations during sessile single droplet drying, but the results indicate that the morphology is also influenced by the faster pilot-scale drying, which was not evident in the slower single droplet drying.

Highlights

The quality of a spray dried powder is determined by, among others, the reconstitution behavior and flowability
The effect of the composition on the morphology was studied by drying all formulations at Tin = 190 °C and relative humidities of the outlet air (RHout) = 8%
The first two groups were expected on the basis of the results obtained earlier with single droplet drying experiments, while the last group represented a mixture of fragmented or agglomerated particles without a distinctive morphology

Summary

Introduction

The quality of a spray dried powder is determined by, among others, the reconstitution behavior and flowability. These properties are influenced by the morphology of the powder particles. To the effect of the droplet size as such, during spray drying there is a wide droplet size distribution and different droplets experience different drying trajectories. These aspects contribute to variation in drying times and probably the morphology

Methods

Results

Conclusion