The digestion of carbohydrates takes place in mouth and small intestine. Its the saliva, secreted by salivary gland which carries out the digestion of 30% of carbohydrates in mouth. There is no any juice which acts only on carbohydrate component of food. The digestion of remaining carbohydrates occur in small intestine by the action of pancreatic juice, which contains fat, protein and carbohydrate digesting enzymes.
Mostly saliva helps in deigestion of food approximately 32% gets digests in the mouth and the fats are digested properly in the small intestine by the juice secreted in the pancreas