Iron oxides and hydroxides are applied to lasered part of the fruit to enhance contrast and make it more visible to human eye (and perhaps to machine eye too). The chemicals were previously not allowed under European Law. Now, laser etched fruits are expected to land European fruit stalls this late June.
When was my last post regarding this laser technique to label fruits. It was over two years ago. It was last February 27, 2011, when it was still in the development stage. I hoped for its adoption and appearance in local stores. Two years have passed and the Europeans are finally adopting. Spreading to the rest of the world would not take another two years I hope.