Microencapsulation using starch as wall material: A review

Microencapsulation is a process oriented to protect substances that are susceptible to decomposition or reduction in their functionality due to different degradation reactions (i.e., oxidation, hydrolysis, etc.). Diverse wall materials, including some carbohydrates, preserve substances against adverse temperature, pH, humidity, oxygen, and other components that can react with the protected material. Starch is a wall material that is widely used for microencapsulation purpose. Unmodified and modified starches are increasingly considered for microencapsulation of vitamins, essential oils, flavors, drugs, and microorganisms. Recently, spherical aggregates of starch using small granules (1–3 μm) were developed for encapsulation purposes. Spherical aggregates are produced when small starch granules in the presence of additional bonding agents (e.g., proteins and hydrocolloids) are spray dried. Some studies have reported the application of spherical aggregates, but they neither report the effects of amylose content nor the molecular weight of amylopectin. In this sense, this review focuses on the state of the art of starch spherical aggregates and the perspectives of their applications as encapsulating agents.