Researchers at Queensland University of Technology report a new understanding of how bananas make and store carotenoids, which are important vitamin precursors for eye health. The findings may help in the development of banana varieties with enhanced health benefits, according to a new study published in the Journal of Agricultural and Food Chemistry.

Vitamin A deficiency is rampant in Africa and Southeast Asia, causing an estimated 250,000 to 500,000 children to become permanently blind each year, the researchers note. Even worse, half of those children die within a year of losing their sight. To combat vitamin A deficiency, other researchers have been investigating methods to boost carotenoids in bananas, because these compounds—which turn fruits and vegetables red, orange or yellow—are converted into vitamin A in the liver. However, this approach has been hindered by a lack of understanding of how bananas produce and store carotenoids.

The researchers studied two banana varieties to find out why they make very different amounts of carotenoids. They found that the pale yellow, low-carotenoid Cavendish variety produces more of an enzyme that breaks down carotenoids. In addition, the orange Asupina variety stashes its carotenoids in microscopic sacs during ripening, shifting the chemical equilibrium in the fruit so it can make even higher levels of these substances. The researchers say their work will provide insights for future developments in the biofortification and breeding of bananas that contain more carotenoids.