In foods, cranberry fruit is used in cranberry juice, cranberry juice cocktail, jelly, and sauce. Cranberry juice cocktail is approximately 26% to 33% pure cranberry juice, sweetened with fructose or artificial sweetener.uice and extracts from the fruit (berry) are used as medicine. Cranberry is most commonly used for prevention and treatment of urinary tract infections (UTIs). Cranberry JUICE seems to help prevent UTIs, but so far it doesn’t seem to be effective in treating UTIs.