Martí-Franquès COFUND Fellowship Programme


Details

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Reference:

2018MFP-COFUND-37

Area:

Engineering and Architecture

Supervisor name and surname:

Sílvia de Lamo Castellví

Supervisor email:

silvia.delamo@urv.cat

Supervisor short biography

Co-supervisor name and surname:

Montserrat Ferrando Cogollos

Co-supervisor email:

montse.ferrando@urv.cat

Co-supervisor institution:

Universitat Rovira i Virgili

Co-supervisor short biography

PhD programme:

Nanoscience, Materials and Chemical Engineering

Title of the research project:

New methodology to produce starters with nutritional applications

Description of the research project:

Encapsulation enables to provide industry with the microorganisms required to optimize food formulations and meet market needs. Microorganisms are commonly preserved by spray drying technology; this process reduces drastically their viability. Moreover, there are some bacteria and yeasts that cannot be dried by this technology because they show an extremely high mortality rate. Emulsions and solid microcapsules have evolved as main strategies to encapsulate bioactive compounds and microorganisms for the food industry. Traditionally emulsification techniques can cause loss of functional properties of the components which have heat and shear sensitivity, and it is also difficult to control the droplet size and their distribution. Membrane emulsification (ME) has been used in the production of simple and multiple emulsions as an alternative to traditional methods; in direct ME the dispersed phase is forced to pass through a microporous membrane, while the continuous phase flows along the membrane surface. On the other hand, the so-called premix ME consists in the production of a coarse emulsion which is then refined by passing through a porous system. The objective of this research project is to encapsulate lactic acid bacteria in double emulsions produced by membrane emulsification and to obtain solid microcapsules, enhancing their possibility of survival. We have worked extensively on using membrane emulsification with organic (e.g. nylon) and inorganic (Shirasu Porous Glass, SPG) membranes to produce single (O/W) and double emulsions (W/O/W) to encapsulate food aromas and phenolic bioactive compounds, respectively. Preliminary studies performed in our research group have showed the potential of successfully encapsulate bacteria in double emulsions by a two-step process combining direct membrane emulsification (production of W/O emulsion), followed by premix ME (production of W/O/W emulsion) and later spry-drying them to obtain solid microcapsules, barely affecting their potential of survival. We have also observed that it is possible to obtain the double emulsions after redissolving the solid microcapsules in hydrophilic solvent. The use of SPG membranes to produce both the W/O and the W/O/W emulsions has not been studied yet and the results are very promising. To achieve the overall objective of this application, we will also use novel technologies as Fourier Transform infrared and Raman spectroscopy combined with multivariate analysis to study the viability of the bacteria encapsulated. We have been using these technologies to rapidly discriminate bacteria and yeast and study mechanisms of inactivation of microorganisms when advanced technologies such as pulsed electric fields and high pressure treatments are applied. We propose a novel approach for producing starters and we anticipate that the survival rate of the bacteria encapsulated by this methodology will be significantly higher than the conventional method (spray drying).

Gross anual salary:

26443.80 €

Dedication:

Full time

Working hours:

37.5 hours a week

Expected start date:

European union This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 713679