In a saucepan, combine the apples, pineapple, sugar, chili flakes, anise, fennel seed, lemon zest, and red wine vinegar and bring to a boil. Reduce the heat and let simmer until reduced by half. Dissolve the gelatin in the water and set aside. Once the liquid is reduced, add gelatin and remove from heat. Transfer to a clean container and let cool to allow the gelatin to set.