Physical and functional properties of cheese powders affected by sweet whey powder addition before or after spray drying

- The method of sweet whey addition influences the properties of cheese powders.
- Lactose state and particle size have a major influence on cheese powder properties.
- Co-spraying of sweet whey powder improve the reconstitution properties.
- After rehydration, cheese powders presented elastic and stable network structure.

Cheese powder properties are affected by the use of different cheese raw materials, addition of ingredients, spray drying and storage conditions. Sweet whey powder can be added after spray drying, in a dry mixing process, or before spray drying into the cheese feed to improve physical properties like flowability, particle size, color and reconstitution properties. This work focused on how addition of sweet whey powder before (co-sprayed) or after spray drying (dry mixed) affected the physical, flow, thermal and reconstitution properties of Danbo cheese powder. It was demonstrated that co-sprayed samples presented smaller particles, faster dissociation, better solubility and rehydration ability (by 1H NMR relaxometry), whereas solid-state 13C MAS NMR and differential scanning calorimetry were utilized to show that lactose was mainly amorphous for co-sprayed powders and mainly present as crystalline lactose monohydrate in dry mixed powders. Also, dry mixed showed the lowest flow functional coefficient and a weaker structure after rehydration (1:1 w/w). Rheological measurements indicated the presence of a stable and elastic network after rehydration. In conclusion, lactose state and particle size are the main factors affecting the properties of cheese powder added sweet whey powder.

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