In a heavy nonreactive saucepan, toss the apples with the remaining 1 tablespoon lemon juice. Add the drained raspberry syrup, cover and cook over moderately low heat for 10 minutes. Gently stir the apples, cover and cook for 5 minutes longer. Uncover and simmer, stirring occasionally, until just tender, about 5 minutes. Stir in the raspberries and remove from the heat.