Final answer:
The company began cooking products in vegetable oil in 1985.
Step-by-step explanation:
The company started cooking products in vegetable oil in 1985. Prior to that, different cooking methods were used. For example, it is estimated that humans first began cooking somewhere between 500,000 B.C. and 75,000 B.C., which dramatically changed the eating experience. Over time, humans discovered how to refine grains and sugars, and how certain cooking and refrigeration methods enhanced food longevity.