Scientists say they have now found out the produce you buy in the shops is still alive and all those blueberries and zucchinis are still responding to the time of day.
Lead researcher, Professor Janet Braam of Rice University says it could spell changes to the way produce is harvested and stored that increase the food’s nutritional value.
“Vegetables and fruits, even after harvest, can respond to light signals and consequently change their biology in ways that may affect health value and insect resistance,” she said in a statement about the paper.
The plants responded to the light by altering levels of chemicals that protect them from being eaten by insects and other herbivores. Unlike animals, plants are made up of many separate parts or modules-leaves and branches, fruits and roots-that can continue to metabolize and survive more or less independently, at least for some time. Even after they’ve been harvested and cut from one another, their cells remain active and alive.
Braam says “They respond to their environment for days, and we found we could use light to coax them to make more cancer-fighting antioxidants at certain times of day. Braam’s team simulated day-night cycles of light and dark to control the internal clocks of fruits and vegetables, including cabbage, carrots, squash and blueberries. The research is a follow-up to her team’s award-winning 2012 study of the ways that plants use their internal circadian clocks to defend themselves from hungry insects. That study found that Arabidopsis thaliana — a widely used model organism for plant studies — begins ramping up production of insect-fighting chemicals a few hours before sunrise, the time that hungry insects begin to feed.
“It may be of interest to harvest crops and freeze or otherwise preserve them at specific times of day, when nutrients and valuable phytochemicals are at their peak,” Professor Braam said.
Some of those same phytochemicals also have anti-cancer effects when people eat them. “Perhaps we should be storing our vegetables and fruits under light-dark cycles and timing when to cook and eat them to enhance their health value.”
“We cannot yet say whether all-dark or all-light conditions shorten the shelf life of fruits and vegetables,” Braam said. “What we have shown is that keeping the internal clock ticking is advantageous with respect to insect resistance and could also yield health benefits.”
Ref: Current Biology Journal http://www.zoominfo.com/p/Janet-Braam/71229356