Background, Context or Rationale Spray drying is widely used in the dairy industry to produce powders with encapsulated oil droplets. For these products, the amount of free surface oil critically determines product properties. Understanding the mechanisms leading to an excellent encapsulation of oil could help to maximise the product quality of dairy products. Aim(s) This study investigates the role of the locking point on the encapsulation of oil by varying oil concentration, initial drying temperature and matrix material. Methods We used a multi‐scale approach combining encapsulation data from single droplet drying (SDD) experiments achieved with semiquantitative Raman spectroscopy and data from spray‐dried powders achieved with conventional solvent extraction. Major Findings Our findings reveal that less oil is encapsulated for parameter changes leading to a later locking point. Conversely, an earlier locking point, achieved by increasing the drying temperature, significantly improves encapsulation efficiency in spray‐dried powders. Substituting maltodextrin with a modified starch reveals potential influences on the morphology, with poorer encapsulation despite a shorter time to the locking point. The semiquantitative Raman measurements on SDD particles provided insights into surface composition, which correlated well with the general trend of encapsulation efficiency measured by solvent extraction in spray‐dried powders. Scientific or Industrial Implications This study highlights the locking point as a crucial parameter for encapsulation success and offers a powerful analytical toolbox for optimising spray‐drying processes to enhance oil encapsulation in spray‐dried emulsion powders.
Höhne et al. (Thu,) studied this question.