Pour pineapple tidbits, including the juice, into. 8-in. (20-cm) square metal pan or a similar-size freezable container. Stir in lime zest and lime juice. Cover and freeze 1 1/2 to 2 hr., until almost frozen through.
Transfer mixture to food processor; pulse until just slushy
Divide among 4 serving bowls. Sprinkle with toasted coconut.