Pre-heat oil to 350 degrees in medium frying pan. In a medium, mixing bowl, combine coconut and panko. Dredge shrimp in flour, then in the egg mixture, then in the panko and coconut mix, pressing down firmly to ensure proper breading. Fry shrimp until golden brown. Be sure not to burn. The coconut contains a high sugar content, which may burn quickly. In a separate saucepan, combine sugar, vinegar, and pineapple juice. Bring to a boil and allow sugar to incorporate into the sauce. Add guava concentrate and allow to boil. Mix the cornstarch and water to make a slurry. You may use cornstarch slurry to thicken the sauce to the correct consistency. The sauce should be able to coat a spoon. You may use the sauce as a dip or simply pour the sauce over the shrimp when ready to serve.