GROWING LIST. “Researchers have proposed new receptor cells on the tongue for detecting calcium, water and carbonation. The growing list of putative tastes now includes soapiness, lysine, electric, alkaline, hydroxide, and metallic.” And fattiness. Taste sciences has “made more progress in the last 15 years than the last 100.”
http://well.blogs.nytimes.com/2014/07/21/a-budding-club-of-tastes/?_r=0