Are black turtle beans the same as black beans? What is the difference - if any - between the two?
Technically speaking, yes they are different, but most people in the United States - even restaurants and chefs - use those names interchangeably, which makes it even more confusing.
Officially, black beans are Asian and come from black soybeans. They are also called Chinese black beans.
Black turtle beans (or black turtle soup) are popular in Central and South American cuisine (frijol negro in Spanish, feijao in Portuguese). For example, a Mexican black bean burrito will use frijoles negros a.k.a. turtle beans.
What you don't need to be confused about is how much antioxidants they have. The good news is that both have a similarly high ORAC value, so whichever version you're getting, you can take comfort in that fact.
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010