Adzuki Bean

The adzuki bean is a small annual vine, its seed about five millimeters long, widely cultivated across East Asia; most cultivars are uniformly red, though white, black, gray and mottled varieties also exist. Its wild Japanese ancestor is believed to be the progenitor species, with domestication dated to roughly 3000 BC and the oldest cultivation traces found in Japan's Central Highlands from 6,000 to 4,000 years ago, though genetic diversity is highest in central China, leaving the exact origin unsettled. As of 2006, China was the largest producer with 670,000 hectares planted, followed by Japan, South Korea and Taiwan, and Japan is the largest importer; the beans are traditionally boiled with sugar into red bean paste, used in Japanese sweets such as dorayaki and anpan, Chinese dishes such as mooncakes and zongzi, and Korean patbingsu, and cooked beans are about 66 percent water and 25 percent carbohydrate, with a notably high folate content.