In a bowl, mix the sugar with the juice, stirring until all the sugar is dissolved. Stir in the milk gradually, until it is also fully incorporated and the mix is smooth. Pour into a shallow dish and store in the freezer until firm. Remove from refrigerator, break into small chunks, and beat with an electric mixer until the preparation is smooth. In a separate bowl, whip the evaporated milk until it is stiff (which pumps air into the mixture to form a firm and stable foam). Fold into the previously frozen mixture. Return the mixture to the freezer.