Spray drying encapsulation of probiotics and enzymes

Spray drying is one of the most frequently used encapsulation techniques. The incorporation of different active compounds in small capsules contributes to their protection and stability. Applications of spray drying of food ingredients are constantly being developed for the food industry due to the simplicity, low cost, effectiveness and versatility of this technique. Probiotics and other active compounds, such as enzymes, can be encapsulated by spray drying by combining various carrier materials, such as maltodextrins, gums, modified starch or alginate. However, exposure to high temperatures can be injurious to the integrity of probiotic cells or enzyme activity and can cause irreversible changes. Approaches such as enhancing pre- and post- spray drying steps are crucial to maintaining the integrity of these active compounds in the dried powders. This review focuses mainly on two major factors affecting the survival of probiotics and the activity of enzymes during spray drying, namely, the choice of carrier/wall material and drying temperature, bringing new light on how these influence post-drying characteristics of the final products.