Stabilization mechanisms of oil-in-water emulsions by Saccharomyces cerevisiae

Author(s)

Paiva Moreira, Thais Caldas ^[1] ; da Silva, Vanessa Martins ^[1] ; Gombert, Andreas Karoly ^[1] ; da Cunha, Rosiane Lopes ^[1]

Affiliation

^[1] Univ Campinas UNICAMP, Fac Food Engn FEA, Dept Food Engn DEA, Rua Monteiro Lobato 80, BR-13083862 Campinas, SP - Brazil

• Document type: Journal article
• Source: COLLOIDS AND SURFACES B-BIOINTERFACES; v. 143, p. 399-405, JUL 1 2016.
• Web of Science Citations: 3

Abstract

A multiphase system is commonly formed during the oil production by microbial route, which can lead to stable emulsions hindering product recovery. Thus, this study aimed to investigate the mechanisms of emulsion stabilization by the yeast Saccharomyces cerevisiae in order to contribute with processes development of oil production by fermentation. A model system using hexadecane as oil phase and yeast suspension as aqueous phase was used to prepare O/W emulsions. The yeast was subjected to different treatments as inactivation (autoclaving) and washing before to be resuspended in water. The washing water (water from the first washing) and suspension of commercial yeast (active) were also used as aqueous phase. After 24h of preparation, the emulsions separated into three phases: top (cream), intermediate, and bottom phase. The top or cream phase was a concentrated emulsion that kept stable during seven days, except for those prepared from washed yeast that were stable only for a short period of time. Emulsions prepared with washed yeast showed higher cell adhesion to the droplets interface, which implied in a higher amount of yeast into the cream phase in comparison to other formulations. Therefore, yeast cells adhesion plays a role on emulsion stability, but the greater contribution was provided by cell material dispersed into the aqueous phase, regardless of cell viability. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• 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: 11/06083-0 - Emulsification by microchannels
• Grantee: Rosiane Lopes da Cunha
• Support Opportunities: Regular Research Grants