place peeled pomelo and blueberries in blender and finely blend, make 2 tbsp. of zest from pomelo and set aside. Simmer sugar and water for 10 minutes. In another bowl beat egg whites until foamy and set that aside. Add pomelo zest to sugar mixture and cook it for 5 minutes, then remove from heat and be sure to let cool down or place in fridge for 15 to 20 minutes. In a larger bowl add your 2 tbsp. of lemon juice and then add your fruit mix and sugar water. Fold in beaten egg whites along with cream. Use a blender to blend the ingredients on low to medium for about 3 to 4 minutes. Then put it in a bowl larger than a quart and place it in the freezer for 10 minutes then take out and stir it 4 times then place back in freezer, continue this process for about 30 minutes. Makes over a quart.