Hybrid oil-in-water emulsions applying wax(lecithin)-based structured oils: Tailoring interface properties

Author(s)

Okuro, Paula K. ; Gomes, Andresa ; Cunha, Rosiane L.

• Document type: Journal article
• Source: Food Research International; v. 138, p. 11-pg., 2020-12-01.

Abstract

This study addressed the impact of fruit wax(lecithin)-based oleogels as dispersed phase in formation and stability of oil-in-water emulsions. These hybrid emulsions were prepared above the melting point of the oleogels, using Tween 80 (T80) or whey protein isolate (WPI) as emulsifiers. Both mono- and mixed-component oleogels comprised of fruit wax (FW) or FW + lecithin (FWLEC), respectively, were studied as lipid phases. After hot-homogenization, emulsions were submitted to quiescent cooling and stored over 14 days at 5 or 25 degrees C, in such temperatures supposed to assist or hinder oleogelation, respectively. Time course promoted a slight decrease in zeta potential only for WPI-stabilized emulsions and particle size distribution was shifted to larger size values, but showing a lesser extent to those stored at 5 degrees C. The presence of oleogels improved kinetic stability of emulsions compared to liquid oil at both temperatures, disclosing the role of the combined effects of the type of emulsifier and oleogelator(s)-emulsifier interactions. These outcomes are associated with the interfacial activity played by both oleogelators, but mainly lecithin that led to lower values of interfacial tension. In addition FWLEC combined with WPI showed the lowest complex modulus from dilational rheology, which can be related with WPI-LEC complex formation. Overall, results suggest that oleogelators migrated to the O/W interface of dispersed droplets, no longer reflecting oleogel bulk properties and showing a more complex behavior. However, the formation of more complex structures at the interface favored greater stability of the emulsions. Thus, the new perspective of oleogel-inspired fat droplets in hybrid systems can expand the conventional approach of oil structuring to create mixed interfaces tailoring oil-in-water emulsions properties. (AU)

• FAPESP's process: 18/20308-3 - Designing oil structured colloidal systems towards enhanced bioavailability of bioactive compounds on in vitro digestibility behavior
• Grantee: Paula Kiyomi Okuro
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 11/06083-0 - Emulsification by microchannels
• Grantee: Rosiane Lopes da Cunha
• Support Opportunities: Regular Research Grants
• FAPESP's process: 09/54137-1 - Acquisition of a particle size/distribution analyzer, a zeta potential measurement system, a spray dryer, and an ultra-high-pressure liquid chromatograph/mass spectrometer
• Grantee: Miriam Dupas Hubinger
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 19/26348-0 - Encapsulation of non-polar bioactive agents in conventional emulsions, Pickering Emulsions, or nanoemulsions: application in active films, and activity conservation and controlled release studies
• Grantee: Andresa Gomes Brunassi
• Support Opportunities: Scholarships in Brazil - Post-Doctoral