Preventing browning of the apple slices during baking can be achieved through a few simple methods. Firstly, soaking the apple slices in a mixture of water and lemon juice, as outlined in the recipe, effectively halts the oxidation process that causes browning. Additionally, while the apple slices will brown slightly during baking due to caramelization, using varieties with a firmer texture, such as Gala or Braeburn, can minimize this effect. Moreover, cover the apple roses loosely with aluminum foil during the first part of baking if you notice them browning too quickly. This will help maintain moisture around the apples and ensure that both the pastry and apples cook evenly without excessive browning.