Modelling an electroporation treatment for the extraction of bioactive compounds from blackcurrant

MAITE GAGNETEN; SAMO MAHNIč-KALAMIZA; GRACIELA LEIVA; CAROLINA SCHEBOR; NAHUEL OLAIZ

Congreso; 3rd WCE PEF-BMFET; 2019

Blackcurrant is a berry fruit rich in bioactive compounds such as flavonols andpolyphenols, which contribute to its antioxidant activity and biological functions. Theseproperties have raised the interest on its consumption. However, due to its highperishability and strong acid taste, its fresh consumption is limited. Therefore, the useof its bioactive compounds for the development of functional foods appears as aninteresting alternative. In other work, different electroporation treatments were analyzedto improve the extraction yield of these compounds in the juice. In order to have abetter understanding of the effects of different PEF parameters on food processing anddevelop an optimal strategy to improve PEF treatment with extraction purposes, atheoretical model was performed. In silico experiments (numerical simulations) are avaluable tool to study the influences of tissue properties, electrode design and electricpulse delivery scenarios in the process of electroporation. In this work, a numericalmodel was performed to fit experimental results and then was used to optimize theprocess parameters (electrodes, pulses, etc). The in silico model consists in thenonlinear solution of the Laplace equation to model the behavior of the electric current,the electric field, the temperature and the medium conductivity in the extractionprocess. The total energy was calculated with the applied voltage between electrodes,total electric current and pulse time. The experimental assays were performed in acustomized laboratory scale chamber with needle electrodes on IQF blackcurrant fruits.Electric current, voltage pulses and time were recorded and temperature changes weremeasured with an infrared thermometer.The presented model was able to predict the evolution of the electroporation front,electric current and temperature variations. As expected, the model showed that theelectric field intensity presented a non-homogenous distribution along the treatedsample. However, it was observed that the intensity was sufficiently high for most of theelectroporation chamber area, suggesting that a needle electrode system can be usedfor extraction processes of fruit juice.