Line loaf pan, 9x5x3 inches, with aluminum foil. Brush with oil. Heat 1 cup sugar and the corn syrup to boiling in 1-1/2 quart saucepan over medium-high heat, stirring constantly, until sugar is dissolved. Cook, without stirring, to 280 degrees F. on candy thermometer or until small amount of mixture dropped into very cold water separates into hard but not brittle threads.
While cooking sugar mixture, heat orange juice, pectin and baking soda to boiling (mixture will be foamy) in 2-quart saucepan over high heat, stirring constantly; reduce heat.
Slowly pour hot sugar mixture in a thin stream into orange juice mixture, stirring constantly (this should take 1 to 2 minutes); remove from heat. Stir in food color. Let stand 2 minutes. Skim off foam.
Pour mixture into pan. Let stand, uncovered, at room temperature 24 hours. Lift foil from pan and remove foil from sides. Cut into 3/4-inch squares with knife dipped into sugar. Roll squares in sugar. Let stand uncovered at room temperature 1 hour. Store gumdrops in airtight container.
Grape Gumdrops: Substitute grape juice for the orange juice and blue food color for the red.
Apple-Cherry Gumdrops: Substitute apple-cherry drink for the orange juice and use red food color.