Enhancing phenolic content in carrots by pulsed electric fields during post-treatment time: Effects on cell viability and quality attributes

The impact of pulsed electric fields (PEF) and post-treatment time on the phenolic content and quality attributes of carrots was studied. Additionally, their influence on cellular permeability and viability was analyzed. Carrots were subjected to different electric field strengths (0.8, 2 and 3.5 kV·cm−1) and number of pulses (5, 12 and 30). The largest increases in phenolic content were produced 24 h after applying 30 pulses of 0.8 kV·cm−1 (40.1%) and 5 pulses of 3.5 kV·cm−1 (39.5%). At such conditions, the colour was not affected but softening occurred after applying the highest electric field strength. Moreover, the increase in the specific energy input correlated with the decrease in cell viability. Carrot weight loss over time, media conductivity increase and cell viability decrease are related to the destabilization of cell membranes, which would entail a physiological response to stress, leading to a higher content in phenolic compounds.This research has been financed by the Ministerio de Economía y Competitividad (Spain) reference AGL2013-44851-R