Huh. I don't taste triglycerides. Peanut oil is just oily to me. The one paper that was linked studied the perception of fatty acids which although they are lipids, are not fat per se. Fat is triglyceride, which is a gycerol esterified to three fatty acids. Vegetable oils are ~99.9% triglyceride. Solid fat is made of triglycerides with longer carbon chains that remain solid until heated to their melting temp. Fatty acids are not free in fat unless it has gone rancid and begun to break down. Fatty acids are liberated from fat when mixed with saliva by the enzyme lipase. But unless one chews a lot without swallowing, the fatty acids wouldn't seem to have much time to accumulate where they could be tasted. Sensing fatty acids isn't so novel. The shorter chain ones have odor..acetic is vinegar, propionic is cheesy, butyric is vomity, caprilic and caproic are goaty (hence their names). I'd love to see the other references. Interesting stuff.