The hit TV series "Lychees of Chang'an" depicts Emperor Minghuang of the Tang Dynasty, who, to impress Yang Guifei, sent lychees from Lingnan to Chang'an. To preserve the fruits' color, aroma, and flavor, the entire lychee tree had to be cut down and then transported by express post. This deeply evokes the difficulties of preserving and transporting lychees. Lychees change color in one day, their fragrance in two, their flavor in three, and their color, aroma, and flavor are all gone in the fourth day. Therefore, preserving lychees is a common concern.