You can add a little invert sugar to some recipes, like brioche, in the place of sugar.  I have noticed the difference, as it made my brioche rolls moist and apparently it will also help preserve the brioche.  It could also be possible to use honey instead (which is a natural invert sugar).

For more info you can check out Chef Eddy’s very comprehensive article, which includes a recipe for making invert sugar yourself at home.

Note:  in Barcelona (where I live) you can buy it at Gadgets Cuina.