Observed multiple employee personal drinks (in single use cups with straws, without straws, and in cans) and personal food stored on prep counters in the back kitchen. Container of personal food was open and being eaten in the kitchen. CA: Instructed PIC that personal drinks stored in the kitchen must be in a single use cup with lid and straw and be stored on a bottom shelf, not on counters. Drinks in any other container must be kept in a designated area not in the prep kitchen. Food cannot be eaten in the kitchen. If there isn't designated space in the office for eating, then employees must eat at a table in the dining room. PIC immediately corrected the food and drinks.