REVIEW ARTICLE Tour of Truffles: Aromas, Aphrodisiacs, Adaptogens, and More Kirsten Allen a,b and Joan W. Bennett b a Department of Plant Biology, Rutgers, New Use Agriculture and Natural Plant Products Program, The State University of New Jersey, New Brunswick, NJ, USA; b Department of Plant Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA ABSTRACT Truffles are the fruiting bodies of ascomycete fungi that form underground. Truffles are glo- bally valued, culturally celebrated as aphrodisiacs, and highly sought-after delicacies in the culinary world. For centuries, naturalists have speculated about their mode of formation, and in cultures surrounding the Mediterranean Sea, many species have been prized as a delect- able food source. Truffle fruiting bodies form underground and emit a variety of volatile organic compounds (VOCs). Truffle volatiles are believed to have evolved to attract animals that disperse their spores. The main VOCs identified from truffles include sulfur compounds, such as dimethyl sulfide (DMS) and dimethyl disulfide (DMDS); in addition, 1-octen-3-ol and 2-methyl-1-propanol have been found in most truffle species. Humans use pigs and dogs trained to detect truffle VOCs in order to find these prized subterranean macrofungi. Truffles have pharmacological potential, but until more reliable cultivation methods become avail- able their high price means they are unlikely to see widespread use as medicinals. ARTICLE HISTORY Received 28 April 2021 Accepted 26 May 2021 KEYWORDS Truffles; VOCs; ascomycetes; gourmet fungi; aromas Introduction Truffles are the subterranean reproductive structures of hundreds of species of fungi belonging to the class Ascomycetes. Gourmets value a few species of truffles for their exquisite flavor and aroma. They are also purported to be aphrodisiacs. In particular, two species, Tuber magnatum, the “white truffle,” and Tuber melanosporum, the “black truffle,” are considered among the most delectable of all edible fungi. In recent years, the yield of truffles has dropped while the demand has grown, leading to extremely high prices [1]. Depending on the species, 1 kg of truffles can range from e600 to e6000 [2,3]. In 2010, a single, large (900 g) white truffle was sold to Jeannie Cho Lee, a South Korean wine critic liv- ing in Hong Kong, for $144,000 [4]. Gourmet truf- fles cost so much that they have gained monikers like “underground gold” and “diamonds of the kitchen” [5,6]. One online gourmet site pointed out that truffles now cost more than cocaine [7]. In this brief “tour of truffles,” we review the his- tory, taxonomy, and collection of these interesting hypogenous fungi; describe the chemistry, flavor, and purported aphrodisiacal properties of their aroma compounds; summarize contemporary research on the physiological activity of truffle metabolites; and conclude with some material about the promised medical potential of their nat- ural products. History As early as 1600 B.C. an anonymous source described truffles as “mysterious products of the earth.” The Greek philosopher Theophrastus (c. 370  286 BCE) wrote descriptions of truffles in Historia plantarum regarding their reproduction and physiology, and the Roman orator Cicero (106  43 BCE) called truffles the “children of the earth.” The Greek physician Dioscorides (CE 40  90) classified truffles as “tuberous roots” [8]. Pliny the Elder (also called Gaius Plinius Secundus, CE 24  79) and other Greco-Roman writers associated the prolifer- ation of truffles with thunderstorms and attributed their appearance to the action of lightening [9–11]. It is believed that many of the truffles described in Greco-Roman times were what we now call “desert truffles” in the genus Terfezia. They differ from truf- fles in the genus Tuber in that their odor is not as strong, their flesh is not marbled, and they grow in drier climates. They are called terfez by the Arabian people of North Africa and referred to as kame in Eastern Asia [11]. It has been hypothesized that the manna described in the Hebrew Bible, the food which fed hungry Israelites wandering in the desert, CONTACT Joan W. Bennett profmycogirl@yahoo.com ß 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the Korean Society of Mycology. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. MYCOBIOLOGY 2021, VOL. 49, NO. 3, 201–212 https://doi.org/10.1080/12298093.2021.1936766