Ňuña beans, or Andean popping beans, are the lost food of the Incas.
The ñuña bean is an Andean subspecies of Phaseolus vulgaris, Phaseolus vulgaris ñuñas (Phaseolus vulgaris L.). The seeds of ñuña beans are round, multicolored, and look like pigeon eggs. The beans explode when heated, exposing the inner part, like popcorn.
Raw ñuña beans contain approximately 20% protein and have a high amount of starch, moisture, and fibers. The pooping sounds heard when heated appears to be a result of the presence of starch and water in the beans.
The cooking of the ñuña beans utilizes heating until the beans rapidly expand with a pop. The bean is widely cultivated in the Andes, but almost unknown elsewhere. Electrophoretic analysis of a ñuña bean protein extract revealed that the main protein was nearly pure phaseolin. Amino acid analysis of a ñuña bean extract showed that it was rich in the amino acids glutamine, glutamic acid, asparagine, aspartic acid, leucine, lysine, phenylalanine, and serine. However, the beans are deficient in sulfur-containing amino acids.
Ňuña beans are a protein rich food. Ňuña bean protein extracts are also useful as protein supplements, for example, in sports drinks or as additions to vegan yogurt products.
How to cook Nuna beans: http://michigancottagecook.blogspot.com/2013/02/how-to-cook-nuna-beans-beans-that-pop.html
Inca Empire: https://en.wikipedia.org/wiki/Inca_Empire
Know your Nuna bean: https://sites.google.com/site/knowyourvegetables/know-your-beans/know-your-nuna-bean
Lawrence MC, Izard T, Beuchat M, Blagrove RJ, Colman PM. Structure of phaseolin at 2.2 A resolution. Implications for a common vicilin/legumin structure and the genetic engineering of seed storage proteins. J Mol Biol. 1994 May 20;238(5):748-76. doi: 10.1006/jmbi.1994.1333. PMID: 8182747. https://pubmed.ncbi.nlm.nih.gov/8182747/
Lost crop of the inkas: https://www.nap.edu/read/1398/chapter/20
Phaseolus vulgaris, common bean, or French bean: https://en.wikipedia.org/wiki/Phaseolus_vulgaris
Phaseolin protein: https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/phaseolin
The Nuna Bean: https://www.usda.gov/media/blog/2015/08/25/nuna-bean-power-popper-has-funny-name-serious-nutritional-benefits