The tubers are highly palatable with culinary characteristics of a potato, although the flavor can be somewhat nuttier than a potato and the texture can be finer. Studies in rats suggest that raw tubers should not be consumed. They contain harmful protease inhibitors that are denatured by cooking. These tubers contain roughly three times the protein content of a potato (16.5% by dry weight), and the amino acid balance is good with the exception of cysteine and methionine. "Apios americana" tubers were found to have a protein concentration of . This was similar to that of other species in the Apios genus, "A. carnea" and "A. fortunei". However, "A. americana" had larger levels of genistein than the other two species. The fatty acid content of tubers is approximately 4.2% to 4.6%, with linoleic fatty acids predominating. Thirty-six percent of the fresh weight of a tuber is carbohydrate (primarily starch). The tubers are also an excellent source of calcium and iron. Calcium content is 10-fold greater than a potato and iron is 2-fold greater than a potato, although vitamin C was considerably less than a potato. The tuber and the flower also contain mono and oligosaccharides. The tuber has more monosaccharides and oligosaccharides than the soybean, potato, and sweet potato.