New insights into Citrus genus: From ancient fruits to new hybrids

Citrus fruits are among the most ancient known and have always attracted the interest of humans, from both a nutritional and a health point of view. Even though there is substantial scientific literature regarding the Citrus genus and associated isolated bioactive compounds, there are still few studies on the botanical features, the phytochemical profiles, and the biological activities for some ancient Citrus fruits as well as for new hybrids that have become part of the internationalmarket.We have witnessed both the rediscovery and revaluation of some cultivated ancient fruits in some limited areas and the introduction of new hybrids destined to the food, ornamental, and food design market. This is the first review that sheds light on the botanical and chemical features aswell as on the biological properties of Citrus fruits that are under-investigated, localizing them in an international context. Themanuscript focuses in particular on five under-investigated species: Citrus australasica F. Muell. (Finger lime), Citrus medica L. var. sarcodactylis Swingle (Buddha’s hand), Citrus junos Sieb ex Tan. (Yuzu), Citrus limon (L.) Osbeck var. pompia Camarda (Pompia), and Citrus lumia Risso (Lumia).