Chinese emperors ran express horse relays just to get lychees fresh
Lychees spoil fast, and the Han court wanted them anyway. In the first century, riders on fast horses carried fresh fruit from Guangdong to the capital, and centuries later Emperor Xuanzong paid dearly to indulge his consort Yang Guifei's favourite fruit. The rose-scented flesh still loses its perfume when canned.
The lychee, Litchi chinensis, is the only species in its genus and belongs to the soapberry family. The evergreen tree usually stays under 15 metres but can reach 28, with glossy, water-shedding leaves that look strikingly like those of the laurel family, probably through convergent evolution. Clusters of hundreds of small fragrant flowers give way to fruit that ripens in 80 to 112 days: roughly 20 grams each, with a tough red shell hiding translucent white flesh, botanically an aril, around one dark seed. Fruits whose seeds are shrivelled, called chicken tongues, sell for more because they hold extra flesh.
Its perfume comes from compounds including linalool, geraniol and cis-rose oxide, which lend rose and citrus notes, with sucrose, glucose and fructose for sweetness and malic and citric acids for tang. Raw lychee is 82 percent water and a rich source of vitamin C, about 72 milligrams per 100 grams.
Cultivation in southern China is documented from 1059, though unofficial records reach back to 2000 BC, and genome studies point to two separate domestications in different parts of ancient China. The Song dynasty official Cai Xiang wrote an entire treatise on the fruit. Spanish friars praised it in the 1570s, and the Polish Jesuit Michał Boym described it for Western readers in 1656. Chinese immigrants took it to Jamaica in the eighteenth century, where Selena Wong's lychee cake, created in 1988, became a national favourite. Today China leads production, followed by India and Vietnam, from some 200 cultivars.
There is a darker side. Lychee seeds contain methylenecyclopropylglycine, which lowers blood sugar. Since the late 1990s, outbreaks of brain illness among children in India and northern Vietnam during the harvest have been linked to eating the fruit; a 2013 investigation by the US Centers for Disease Control found low blood sugar was common among the undernourished children affected, and 44 percent of cases were fatal.
Source: Lychee
