Morphological and Physicochemical Characterization of Native Beans Reintroduced to the Andean Zone of Jujuy, Argentina

The objective of this work was to characterize the morphology and physicochemical properties of 15 genotypes of native beans from the province of Jujuy, Argentina, 10 of which are ñuñas. The morphological descriptors used were length, width, thickness, and color. Hydration capacity (HC), popping yield (PY), proximal composition, and 100-seed weight (100 W) were also determined. The ñuñas presented rounded shapes and, in general, were smaller than beans since lower values of length and 100 W were observed (9–12 mm and 31.4–48.8 g, respectively, versus 13–15 mm and 40–55 g for beans). No differences were observed between both groups in width (8–7.5 mm), while thickness was more variable in ñuñas (5.8–7.3 mm versus 5.8–6.7 mm for beans). The ñuñas ranged in colors, including whitish, brown, purple, and reddish examples, with a mottled, rhomboid bicolor, and tricolor patterns. The beans ranged from light brown to dark purple, either single-colored or with wide bicolored stripes. Darker colors might indicate the presence of polyphenols and anthocyanin. The physicochemical properties depended on the genotype; the ñuñas presented higher HC (50–67%) and PY (20–36%). The protein content—a key characteristic of legumes—varied between 18 and 25% for all the varieties studied, while lipids ranged from 0.23 to 1.29%. In conclusion, these different characteristics of each genotype could exhibit varying behaviors in response to treatments applied for industrialization. In the canning industry, high values of HC are preferred, while PY describes the ability of ñuñas to expand when exposed to heat.