Time-Sensitive Fruit & Veg
The way in which fruit and vegetables are stored and the time of day that they are eaten could impact their nutritional value, according to a study by researchers at Texas’ Rice University, published in US journal Current Biology in June 2013.
Fruits and vegetables remain alive after being harvested, and research has found that many work in ‘circadian rhythms’ – meaning they are able to alter the levels of chemicals they produce in response to changing light signals, in order to protect themselves from being eaten.
The study found that the light/dark (day/night) cycle activates the release of natural pesticides (called glucosinolates) before the time that the plant’s predators typically feed. This process can last for up to a week after harvest. The chemicals produced affect flavour and nutrition, and have previously been shown to lower the risk of prostate cancer in humans.
The research initially focused on cabbage, exposing some leaves to a 12-hour cycle of daylight and darkness, and others to permanent light or darkness. Those kept in a natural day/night cycle contained higher levels of the insect-repelling chemicals. Further experiments with other fruit and vegetables showed that they all suffered less damage from pests when kept in the natural cycle.
"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," said study co-author Janet Braam.
For more insights into innovative food preservation solutions, see Fresh Thinking: Preservation Innovation.