Luis Trabanco's eyes twinkle with regularity as he greets and serves customers at La Tropicana, the gem of a Hispanic market he and his family run on Lindenwood just west of Kingshighway in South St. Louis. But he got an absolute glow the day we asked the Cuban native to make us some authentic Cuban coffee, almost candylike in sweetness and packing a kick exceeded only by the one most expatriates would like to give Fidel. ¡Viva Luis! ¡Viva Tropicana!