Puree cantaloupe with lemon juice and set in a very fine mesh strainer over a large bowl in the refrigerator. Let drain for 1 hour. Discard drained juice and stir allulose into the puree.
Combine all remaining ingredients in a blender and process until combined. Refrigerate for at least an hour and up to overnight.
Pour the refrigerated base into your ice cream maker and churn according to the manufacturer’s directions. When it starts to become solid, slowly pour in the reserved cantaloupe puree and continue churning until the ice cream is firm.
Serve immediately or transfer to a freezer-safe container and freeze.