Identificador: TDX:3089
Autors: Kaade, Wael
Resum:
Lemon oil, is rich in unsaturated and oxygen functionalized terpenes making it susceptible to oxidation caused by oxygen, light and heat. To limit aroma degradation or loss during processing and storage, encapsulation, through emulsification, of essential oils prior to use in foods or beverages is a common practice. In this thesis, lemon oil-in-water emulsions with narrow droplet size distribution were produced by means of a novel low-energy high-throughput dynamic membrane of tunable pore size (DMTS) system. Emulsions were stabilized with a whey protein-carboxymethyl cellulose electrostatic complex to assess the impact of electric surface charge and the interfacial thickness on the physical and chemical stability of the emulsions
WP-CMC stabilized emulsions conserved the initial color of the emulsion for 7 days at room temperature and under refrigeration. Also, using a conventional membrane emulsification method, WP-CMC stabilized emulsions maintained their aromatic profile for two weeks.
Results showed that using the DMTS system, stable lemon oil emulsions (of 2-3 µm droplet size) can be produced with 40%wt oil fraction. These results are the highest reported droplet break-up for premix membrane emulsification (0.05 < d3,2 / dv < 0.2). Also, a modified version of the DMTS system, called layered DMTS, produced emulsions with narrow size distribution (span ≤1). Emulsions stabilized with the WP-CMC complex had the lowest reported span value of 0.82. Results obtained with the modified DMTS showed that major cutbacks in the system energy requirements can be done without compromising the quality of the emulsions (droplet size and dispersion, dispersion, stability, flux).
For that reason, the DMTS system, and the layered DMTS in particular, is a low-energy, high-throughput microporous emulsification technology that has more potential for scaling-up than other low-energy emulsification systems.
Repositori URV