Nutritional, Thermal, and Energetic Characterization of Two Morphotypes of Andean Mashua (Tropaeolum tuberosum Ruiz & Pavón) Flours from Peru.

Tropaeolum tuberosum (mashua) is a native Andean tuber recognized for its high nutritional and bioactive compound content. Among the various morphotypes, the black and yellow variants show potential differences in composition and functionality. This study aimed to compare the thermo-energetic, nutritional, and physicochemical characteristics of two morphotypes (black and yellow) of Tropaeolum tuberosum flour from the Peruvian Andes. Flours were obtained from tubers harvested in Ayacucho, Peru, and analyzed using elemental analysis for carbon, hydrogen, nitrogen, and sulfur (CHNS), inductively coupled plasma optical emission spectrometry (ICP-OES), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and bomb calorimetry. The empirical formula is CH1.74O0.91N0.06S0.005 for black mashua and CH1.78O0.92N0.05S0.005 for yellow mashua. Black flour exhibited higher protein (17.6% vs. 14.8%) and fat contents (8.0% vs. 6.7%), along with nearly double the iron content. Both flours showed similar starch granule morphology and gelatinization enthalpy (~2 J/g), but the black flour had higher gelatinization temperatures. Calorimetric analysis revealed a greater net calorific value (qNCV) in black mashua flour (4157 ± 22 kcal/kg) than in yellow flour (4022 ± 19 kcal/kg). The thermogravimetric profiles indicated good thermal stability with approximately 30% residual mass. These findings suggested that black mashua flour possesses superior nutritional and energy characteristics, supporting its application in functional food formulations and energy-rich gluten-free products.