Purple sweet potato, the standard name is purple sweet potato. The world's earliest purple sweet potato variety was obtained by cross-breeding by Japanese sweet potato expert Yoshiki Umebayashi in 1982 and named "Yamakawa Purple". The anthocyanin content is about 20 mg/100 g. Due to the continuous in-depth research on the health-care effects of anthocyanins, purple sweet potatoes are very popular in the market. Currently, China and Japan are at the forefront of the world in purple sweet potato breeding technology, and each of them is constantly developing new varieties and bringing them to the market. Generally speaking, the varieties bred in my country focus on yield indicators, with general yields between 1,500-2,000 kg/mu, such as Yuzi 263, Jingshu 6, 22-1, etc.; the varieties bred in Japan are mainly high in anthocyanins. Breeding goals, such as the Cai Zi variety, the anthocyanin content in fresh potatoes has reached about 160 mg/100 g, and the yield is generally about 1300-1600 kg/mu. In terms of processing, the research level in Japan is currently much higher than that in my country, and has been There are more than 100 processed products on the market, and only more than 10 primary products such as purple sweet potato egg tarts made by KFC are on the market in my country.