Effect of different binders on reconstitution behaviors and physical, structural, and morphological properties of fluidized bed agglomerated yoghurt powder

Abstract

Fluidized bed agglomeration is a widely used technique in the production of instant food powders. In this process, primary particles are agglomerated to give a granule-shaped product with improved instant characteristics compared to the original primary particles. Instant products are easy to use by the consumers and hence are favored over the unagglomerated particles. Depending on the type of binder used and process conditions, agglomerates exhibit different shapes, structures and instant properties. In this study, spray-dried yoghurt powders were agglomerated in a top sprayed fluid bed granulator. The influence of different binders (distilled water, ionic, and sugar-based solutions) on agglomeration growth mechanism, particle morphology, and chemical bonds were investigated. The results showed that sugar-based binders caused large particle size and porosity compared to water binders (p < 0.05). Hydrophilic sugars also improved wettability. b* value of powders enhanced with sugar binders. Protein and stretching vibration of N-H groups were affected by acidity of water and resulted in an improvement of powder solubility. Circularity of particles decreased with the usage of hydrophilic sugar solutions while elongation increased.