Though I have written about the bean Jam, I knew there were two different kind of red beans. One is Red Azuki bean and the other is Cowpea. Red azuki beans is India and Cowpea is Africa in origin. And we are using Cowpea for our sweets. In Japan, Azuki beans are more common comparing to Cowpeas since Cowpeas are less grown and less merchandise. Cowpeas are used for Red bean rice in Japan since Azuki beans are peeled when it boiled and Samurai has prevented from using it as they imagined HARAKIRI from the peeled court in Edo Era.
Both of Azuki beans and Cowpeas are rich in polyphenol and minerals.