"Chemical" is just a really, really vague and poor word choice. I honestly don't understand what people are trying to say when they use it. Food and chemistry are inextricably intertwined. You can't even talk about food without talking about all of the various components food is made up of. Not a single food item out there isn't made up of chemicals. Some found in nature, some created in a lab or factory process. Some healthy, some not. Some with long names, some with short names. Some have effects on food taste, longevity, appearance. Some are inert. It's really a meaningless word to use in the context of one's food.