Comparison between monopolar and bipolar µs range pulsed electric fields in enhancement of apple juice extraction

July 1, 2015

Comparison betwee (…) - 2 MB

Keywords — Bipolar pulses, Juice Extraction, Monopolar pulses, Pulsed Electric Fields

Abstract —The effect of monopolar and bipolar shaped pulses in additional yield of apple juice extraction is evaluated. Applied electric field strength, pulse width and number of pulses are assessed for both pulse types and divergences are analyzed.

Variation of electric field strength is ranged from 100 V/cm to 1300 V/cm, pulse width from 20 µs to 300 µs and number of pulses from 10 to 200, at frequency of 200Hz.

Two pulse separated by 1 second are applied to apple cubes. Results are plotted against reference untreated samples for all assays.

Specific energy consumption is calculated for each experiment as well as qualitative indicators for apple juice of total soluble dry matter and absorbance at 390 nanometers wavelength.

Bipolar… pulses demonstrated higher efficiency and specific energetic consumption has a threshold where higher inputs of energy do not result in higher juice extraction when electric field variation is applied.

Total soluble dry matter and absorbance results do not illustrate significant differences between application of monopolar and bipolar pulses but all values are inside the limits proposed for apple juice intended for human consumption.

A pilot scale treatment chamber with 503 cm3 was used.