Commercially produced fruit cakes have a shiny appearance from the sugary glaze coating the cake's exterior. This glaze has more than cosmetic value. According to Baking 911, a shiny fruit cake keeps longer because the glaze helps to lock in moisture, preventing spoilage. (see reference 1) For your next baked fruit cake, add a glaze as a finishing touch after baking to create the appearance of a professionally baked fruit cake.
Whisk together the corn syrup and juice in a saucepan over medium-low heat until the syrup boils.
Remove the cooled fruitcake from the pan and place it on a wire rack over a baking pan to catch any excess glaze.
Brush the hot glaze over the top and sides of the fruit cake.
Let the cake cool for two hours to set the first layer of glaze.
Bring the remaining corn syrup and juice mixture to a boil over medium-low heat.
Coat the fruit cake with a second layer of glaze and let cool completely before wrapping and storing.