Fresh lychee fruits ( Litchi chinensis Sonn.) cv. Huaizhi at
commercially mature stage were picked from Xili orchard,
Shenzhen, China. Lychees were first peeled and pitted. Purple
sweet potatoes (Ningzhishu No. 1) were washed and steamed
for 30 min then blended with lychee fruits to make a paste.
The slurry was shaped by putting it on plastic film under the
3 mm thick plate sheet for MVD tests.