For liquid flavor, we usually use propylene glycol for most of the flavors and flavoring base material, it can be wildely used in drinks & beverages, candy, baked food, ice cream, etc. But for better heat stable performance for bakery application, or sometimes when propylene glycol can't be used, we will use triacetate and vegetable oil as the carrier.
PG based flavor is both soluble in water and oil, thus it's generally used in many products. Triacetate and vegetable oil based flavor are oil soluble flavor ,it is widely used in bakery, chocolate, etc.
For powder flavor, we usually use glucose powder as the carrier and add delicately blended flavoring base.