If the pen turns green, it means the durian is ripe. If the pen turns yellow, the durian is semi-ripe, but if it turns red it is still raw. Current testing for ripeness involves experts listening to the sound when they gently touch the peel with a tiny stick. Buyers and sellers have often engaged in after-sale disputes when purchased durians were found not be properly ripe, noted Jitwattana Boonlert. Jitwattana said the pen could be used to accurately check the ripeness without having to first cut open the fruit’s peel.

Source: The Nation Bangkok May 07, 2018 07:18 UTC