Encapsulation of non-polar bioactive agents in conventional emulsions, Pickering Emulsions, or nanoemulsions: application in active films, and activity conservation and controlled release studies

• Grant number: 19/26348-0
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): May 01, 2020
• Effective date (End): April 30, 2021
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Engineering
• Principal Investigator: Paulo José do Amaral Sobral
• Grantee: Andresa Gomes Brunassi
• Home Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated research grant: 13/07914-8 - FoRC - Food Research Center, AP.CEPID

Abstract

Several bioactive agents can be responsible for antioxidant and/or antimicrobial activities in active films based in biopolymers. However, these compounds are highly hydrophobic, and then, with a very low solubility in water. Thus, their application as bioactive agent in film-forming solutions whose water is the solvent, is a challenge. This problem can be solved by encapsulating these compounds into O/W emulsions previously to films production. Emulsions are thermodynamically unstable systems. The kinetic stability of emulsions is usually increased by using emulsifiers or very small droplets, such as in nanoemulsions. Another type of emulsion is the Pickering emulsion, which is stabilized by solid particles instead of surfactants. Thus, the main objective of this project is to develop active films based on natural biopolymers and charged with bioactive compounds encapsulated in emulsions O/W, interested in to produce three kinds of emulsions (conventional, nanoemulsion and Pickering emulsion) loaded with bioactive compounds; to study the effect of these bioactive compounds, applied as emulsions, in the main physical properties of films; to study if the biopolymeric matrix of films can protect the bioactive compounds during storage, at room temperature, under three relative humidity conditions; and to study the bioactive compounds release in food simulating media. Some bioactive agents, including rutin, hesperidin, a-tocopherol, b-caroteno, cavacrol, eugenol, resveratrol, linalool, several essential oils, among others, must be chosen. Emulsions will be produced using a rotorstator homogenizer (Ultra-Turrax®). For nanoemulsions production, a microuidizer M-110Y will be used. The active films will be produced using natural biopolymers, such as, gelatin, chitosan, sodium caseinate, cassava starch, pectin, alginate, among others, alone or in blends. After choosing the biopolymer, films will be produced according to a well-known methodology. Films will be characterized to determinations of its main properties, at room temperature. (AU)