Primarily the characterization of the raw materials was performed via standardized methods. Moreover, their interaction with the electromagnetic field was evaluated under different conditions through dielectric properties measurements. According to the results, complex effect of temperature, moisture and effect of composition differences were observed. Moisture content of the material was found to be critical when assessing temperature dependence for dielectric constant and dielectric loss.
In order to achieve the extraction using a micro-emulsions, first, the stable extraction media, the micro-emulsion was established and optimized. Selected micro-emulsions were able to extract up to 83% more carotenoids from wet carrot peel as the conventional organic solvent, ethyl-acetate.
In parallel, the microwave pre-treatment (MWP) and microwave assisted extraction (MAE) of carotenoids from wet carrot peel were studied in order to attain process performance intensification. Although MAE and MWP resulted in similar yield increment (≈30%) compared to conventional extraction, lower temperature level and shorter extraction time enabled better process performance using MAE.
Based on the specified and previously optimized process requirements an industrial design concept was established, giving ground to the exploitation of the technology to further application using different biomass. The developed concept laid on following criteria: 1) Direct MW energy input from the waveguide into the extraction media. 2) Avoid the use of MW transparent material when transmitting energy from the source to the extraction media due to the assembly difficulties of at connecting points at higher temperatures and pressures. 3) Achieve good field distribution in order to perform volumetric heating. 4) Achieve good mixing level of non-homogeneous material in order to enhance substance diffusion and energy distribution (Figure 2).
Dissemination: The development and update of a project dedicated web site in the framework of Fraunhofer’s network was established at the beginning of the project (www.amicrex.eu). Face-to-face dissemination took place through active participation in conferences, forums, info days and workshops, organized both at the national and EU level, such as the Achema trade fair 2015 (Frankfurt, Germany), AMPERE Conference 2015 (Krakow, Poland), WineSense Spring School 2016 (Valladolid, Spain), European Researcher’s Night 2017 (Budapest, Hungary), Anuga FoodTec trade fair 2018 (Cologne, Germany), among others. Published Online and printed dissemination took place
•Sólyom K., Javaid, A.I. Vásquez-Caicedo A.L. Effect of moisture, temperature and Bulk Porosity of Dielectric Properties of Carrot peel. Proceedings of the 15th International Conference on Microwave and Radio Frequency Heating 2015, Krakow, Poland. pp. 48. ISBN 978.83.928784.4.5
• Solyom K., Rosales Lopez P., Esquivel P., Vásquez-Caicedo A.L. Effect of temperature and moisture contents on dielectric properties at 2.45 GHz of fruit and vegetable processing by-products, accepted for publication in RSC Advances.
Exploitation: Following topics are foreseen to be protected through intellectual property rights in order to maximise the exploitation of results: 1) Combined microwave cell disruption and micro-emulsion extraction of carotenoids form biomass on lab-scale. 2) Verified design concept of the continuous industrial system.
