Which ingredient is integral to creating a Sour Apple Coolatta?

The ingredient that is integral to creating a Sour Apple Coolatta is apple flavoring. This flavoring is essential as it defines the primary taste profile of the beverage. The Sour Apple Coolatta is designed to provide a refreshing apple flavor, which is a signature characteristic of the product. Without the apple flavoring, the drink would not achieve its intended sour apple taste, making it the centerpiece of the recipe.

Including other ingredients such as coffee, mango, or mint does not align with the core elements of a Sour Apple Coolatta. These options would introduce different flavor profiles that are not representative of the product's purpose. Therefore, apple flavoring is critical for maintaining the authenticity and identity of the Sour Apple Coolatta.