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

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

Toulouse

Congreso; 3rd WCE PEF-BMFET; 2019

Blackcurrant is a berry fruit rich in bioactive compoundssuch as flavonols and polyphenols, which contributeto its antioxidant activity and biological functions.These properties have raised the interest on its consumption.However, due to its high perishability and strongacid taste, its fresh consumption is limited. Therefore,the use of its bioactive compounds for the development offunctional foods appears as an interesting alternative. Inother work, different electroporation treatments were analyzedto improve the extraction yield of these compoundsin the juice. In order to have a better understanding of the effects of different PEF parameters on food processingand develop an optimal strategy to improve PEF treatmentwith extraction purposes, a theoretical model wasperformed. In silico experiments (numerical simulations)are a valuable tool to study the influences of tissue properties,electrode design and electric pulse delivery scenariosin the process of electroporation. In this work, a numericalmodel was performed to fit experimental results and thenwas used to optimize the process parameters (electrodes,pulses, etc). The in silico model consists in the nonlinearsolution of the Laplace equation to model the behaviorof the electric current, the electric field, the temperatureand the medium conductivity in the extraction process.The total energy was calculated with the applied voltagebetween electrodes, total electric current and pulse time.The experimental assays were performed in a customizedlaboratory scale chamber with needle electrodes on IQFblackcurrant fruits. Electric current, voltage pulses andtime were recorded and temperature changes were measuredwith an infrared thermometer.The presented model was able to predict the evolution ofthe electroporation front, electric current and temperaturevariations. As expected, the model showed that theelectric field intensity presented a non-homogenous distributionalong the treated sample. However, it was observedthat the intensity was sufficiently high for most of the electroporationchamber area, suggesting that a needle electrodesystem can be used for extraction processes of fruitjuice.