Pulsed-electric-field-assisted extraction of anthocyanins from purple-fleshed potato

Abstract

The influence of pulsed electric field (PEF) treatment on the anthocyanin extraction yield (AEY) from purple-fleshed potato (PFP) at different extraction times (60–480min) and temperatures (10–40°C) using water and ethanol (48% and 96%) as solvents has been investigated. Response surface methodology was used to determine optimal PEF treatment and optimise anthocyanin extraction. A PEF treatment of 3.4kV/cm and 105μs (35 pulses of 3μs) resulted in the highest cell disintegration index (Zp=1) at the lowest specific energy requirements (8.92kJ/kg). This PEF treatment increased the AEY, the effect being higher at lower extraction temperature with water as solvent. After 480min at 40°C, the AEY obtained for the untreated sample using 96% ethanol as the solvent (63.9mg/100g fw) was similar to that obtained in the PEF-treated sample using water (65.8mg/100g fw). Therefore, PEF was possible with water, a more environmental-friendly solvent than ethanol, without decreasing the AEY from PFP.