The explanation? The leaf pores are naturally closed in dry environments, in order for the plant to retain its moisture. However, by processing the leaves using pulsed electric field technology, the pores remain open - cutting the drying time almost in half.

This makes more of the leaf’s flavour-bearing cells and substances remain intact even after the leaf has dried.

“So far we have worked with basil. Next up we’re thinking about testing dill”, says Federico Gomez, food technology researcher at the Lund University Faculty of Engineering, Sweden.

The discovery was made more or less by accident:

“My former doctoral student noticed that when processing leaves using PEF technology, the pores did not close, which had a negative effect on her experiments. This was an interesting observation, which I then discussed with Allan Rasmusson, plant physiologist at the Department of Biology, Lund University. We realised that by permanently opening the pores we should be able to shorten the drying time.”

Allan Rasmusson underlines that it is not a matter of massive electric shocks:

“The leaves are stimulated by electrical voltage impulses that are a fraction of what is used in an electric fence. This raises the voltage that is already naturally present in the leaf cells. The leaves continue to live, and we have only caused limited damage to enable the pores to open”, he says.

The technology is still only used in the lab, but since it is not expensive (possibly even cheaper, as it saves energy in the drying process) Federico Gomez believes that it should be high in demand.

Publication: Effect of guard cells electroporation on drying kinetics and aroma compounds of Genovese basil (Ocimum basilicum L.) leaves

Contact:
Federico Gomez
federico [dot] gomez [at] food [dot] lth [dot] se (federico[dot]gomez[at]food[dot]lth[dot]se)