Stamped with ripe fruits

A University of Arizona expert has invented a sticker that can tell users when a bunch of fruits or vegetables has come to harvest.

Mark Riley, an assistant professor at the University of Arizona for agricultural mechanics and biological systems, said gardeners and vendors must throw away thousands of bags of fruit each year because they ripen faster than arrival time. supermarket and consumer hands.

Since there is no simple way to know that a fruit looks fresh but the intestines are still delicious, buyers often choose peaches, pears or melons that cannot be eaten because they are still unripe or cooked Anyway.

Riley invented the RediRipe stamp, with a marking strip that can detect ethylene gas - the gas released when vegetables or fruits ripen. When that happens, the stamp will change from white to blue. The more fruit produced in ethylene gas, the darker the blue.

The discoloration does not happen immediately when stamped, but lasts 24 to 48 hours, depending on the ripening rate, Riley said.

However, this type of stamp is still defective. That is, it does not change color when the fruit is ripe or partially rotten. In addition, not all fruits produce enough ethylene to help the stamps detect.

"There is still a lot to do to improve the label," said Jim McFerson, director of the Washington Fruit Research Committee.

This stamp can go to gardeners next year and go to the supermarket within 2-3 years. Riley says it is expected that each stamp will raise product prices slightly.

T. An