In a small nonreactive saucepan, combine the sugar, vinegar, and fruit juice, bring to a boil, and cook until reduced by three-fourths, or the mixture has thickened like syrup. Remove from the heat and pour the mixture into a small glass bowl. Let cool completely.
Slice each heart of palm into thin strips. In a mixing bowl, combine the hearts of palm, onions, peppers, tangerine segments, tarragon and spinach. Season with salt and pepper. Toss with enough olive oil to moisten the salad. In another mixing bowl, toss the crab claws with olive oil, salt and pepper. To serve, mound the hearts of palm salad in the center of each plate. Lay a couple of the crab claws around the salad. Drizzle the entire plate with the Gastrique. Garnish with parsley.
Yield: 4 servings