Washington: A new study has revealed that the fruits and vegetables we buy in the grocery store are actually still alive.
The discovery suggests that the way we store our produce could have real consequences for its nutritional value and for our health.
"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," Janet Braam of Rice University said.
"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," she said.
Braam and her colleagues earlier found that plants grown in the laboratory change their physiology in important ways over the course of the day, driven by circadian rhythms.
They suspected that food crops would do something similar, perhaps even after they`d been harvested from the field.
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`s team now shows that post-harvest vegetables and fruits can in fact continue to perceive light and, as a result, their biological clocks keep on ticking.
That`s an advantage to the plants because it allows them to alter levels of important chemicals that protect them from being eaten by insects and other herbivores, the researchers found.
When eaten by us, some of those same phytochemicals also have anti-cancer effects.
The researchers made the initial discovery in studies of cabbage . They then went on to show similar responses in lettuce, spinach, zucchini, sweet potatoes, carrots, and blueberries.
The findings are published in the journal Current Biology.