Micro-encapsulation

Microencapsulation is a process in which tiny particles or droplets are surrounded by a coating to give small capsules, with useful properties.[1][2] In general, it is used to incorporate food ingredients,[3] enzymes, cells or other materials on a micro metric scale. Microencapsulation can also be used to enclose solids, liquids, or gases inside a micrometric wall made of hard or soft soluble film, in order to reduce dosing frequency and prevent the degradation of pharmaceuticals.[4]

In its simplest form, a microcapsule is a small sphere comprising a near-uniform wall enclosing some material. The enclosed material in the microcapsule is referred to as the core, internal phase, or fill, whereas the wall is sometimes called a shell, coating, or membrane. Some materials like lipids and polymers, such as alginate, may be used as a mixture to trap the material of interest inside. Most microcapsules have pores with diameters between a few nanometers and a few micrometers. Materials generally used for coating are:

The definition has been expanded, and includes most foods, where the encapsulation of flavors is the most common.[5] The technique of microencapsulation depends on the physical and chemical properties of the material to be encapsulated.[6]

Many microcapsules however bear little resemblance to these simple spheres. The core may be a crystal, a jagged adsorbent particle, an emulsion, a Pickering emulsion, a suspension of solids, or a suspension of smaller microcapsules. The microcapsule even may have multiple walls.

IUPAC definition

Microcapsule: Hollow microparticle composed of a solid shell surrounding a
core-forming space available to permanently or temporarily entrapped substances.

Note: The substances can be flavour compounds, pharmaceuticals, pesticides, dyes, or similar materials.

  1. ^ Amaral, Pedro Henrique Rodrigues do; Andrade, Patrícia Lopes; Conto, Leilane Costa de (2019-09-27). Microencapsulation and Its Uses in Food Science and Technology: A Review. IntechOpen. ISBN 978-1-83881-870-8.
  2. ^ Lamprecht, Alf; Bodmeier, Roland (2010). "Microencapsulation". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a16_575.pub2. ISBN 978-3-527-30385-4.
  3. ^ Silva, Pablo Teixeira da; Fries, Leadir Lucy Martins; Menezes, Cristiano Ragagnin de; Holkem, Augusto Tasch; Schwan, Carla Luisa; Wigmann, Évelin Francine; Bastos, Juliana de Oliveira; Silva, Cristiane de Bona da (2014). "Microencapsulation: concepts, mechanisms, methods and some applications in food technology". Ciência Rural. 44 (7): 1304–1311. doi:10.1590/0103-8478cr20130971. ISSN 0103-8478. S2CID 42045080.
  4. ^ Singh, M. N.; Hemant, K. S.; Ram, M; Shivakumar, H. G. (2010). "Microencapsulation: A promising technique for controlled drug delivery". Research in Pharmaceutical Sciences. 5 (2): 65–77. PMC 3093624. PMID 21589795.
  5. ^ Choudhury, Nitamani; Meghwal, Murlidhar; Das, Kalyan (2021-06-18). "Microencapsulation: An overview on concepts, methods, properties and applications in foods". Food Frontiers. 2 (4): 426–442. doi:10.1002/fft2.94. ISSN 2643-8429. S2CID 237925118.
  6. ^ Fanger, Gene O. (1974), Vandegaer, Jan E. (ed.), "Microencapsulation: A Brief History and Introduction", Microencapsulation: Processes and Applications, Boston, MA: Springer US, pp. 1–20, doi:10.1007/978-1-4684-0739-6_1, ISBN 978-1-4684-0739-6, retrieved 2022-02-28