ABSTRACT
Today, the importance of protein-based drugs and the health benefits of bioactive peptides such as the inhibition of free radicals, antithrombotic, antihypertensive, antimicrobial, angiotensin-I-converting (ACE) inhibitors, anticancer, immunomodulatory, anti-inflammatory, hypercholesterolemia, opiate-like, and metal ion chelating properties have been proven. Despite these benefits, physicochemical instability, undesirable taste and flavor, their interactions with other components, and high hygroscopicity are among the challenges that can affect their biostability, biofunctional properties, and their direct use in pharmaceutical formulations and production of functional products. Accordingly, spray drying encapsulation is an effective process for solving these problems. Nevertheless, in contrast to most other bioactive compounds, the protein/peptide complex structures can lose their biological activity due to instability against shear stress (during atomization) and dehydration (during drying). Therefore, in this chapter, the importance, advantages and disadvantages, and applications of spray drying in stabilizing peptides and proteins are discussed. It also considers the role of polysaccharide-based carriers, proteins, amino acids, and low-molecular-weight surfactants on the physicochemical, functional, flow behavior, adverse flavor, morphology, chemical structure, and biofunctional properties of bioactive proteins and peptides. The results of several studies have shown that the optimization of spray drying parameters is necessary to achieve the highest production efficiency, physicochemical properties, and maintenance of biological activity of peptides and proteins. The efficiency of the drying system, biostability, and bitterness of the peptides are affected by the type and composition of the carriers. Furthermore, consideration must also be given to the complex structure and reaction of peptides/proteins, as a result of shear and thermal stresses, during the spray drying process.
