Electric shocks ‘improve’ dried herbs’ taste, say food tech researchers

Giving brief electric shocks to fresh herbs before drying them could vastly improve the taste of dried herbs, say food technologists and biologists at Sweden's Lund University.

Food technology researcher Federico Gomez has conducted experiments with basil leaves and found leaves dried after short electric shocks tasted and smelled almost as good as fresh.

Basil leaf pores are naturally closed once they go through the drying process, but Gomez posited that by processing them using pulsed electric field (PEF) technology, they would remain open.

In experiments Gomez found this cut the drying time almost in half and made more of the leaf's flavor-bearing cells and substances remain intact after drying.

His research was conducted in conjunction with Professor Allan Rasmusson, plant physiologist at the Department of Biology.

"Federico showed me microscopy pictures of leaves from another plant where the guard cells wouldn't close, so the holes were permanently open. That was really the key to it because if you can keep those open you can dry rapidly and with rapid drying you won't have that much degradation," Rasmusson said.

Leaves are stimulated by electrical voltage impulses a fraction of that used in an electric fence. It raises the voltage already naturally present in leaf cells, allowing them to stay alive, the shocks causing only limited damage to allow the pores to open.

"Leaves of aromatic herbs like basil or dill are very sensitive to drying, so they lose color and aroma very quickly during drying," Gomez told Reuters. "What we do is to affect the leaf in the way these pores are damaged, so they're permanently opened and dehydration is faster."

Gomez insists the taste is far superior to that of commercial dry herbs.

"We can really feel in the mouth the essential oils from the leaves much more than in the commercial dry products," he said.

In addition, Gomez says the technology will cut the cost of drying because it is so much shorter than traditional techniques.

Gomez says the team now wants to test their technique on dill and oregano.

The researchers have filed a patent for the technique and are working with a private company to scale up and commercialize the technique. — Reuters