BIOACTIVE POTENTIAL AND PHYSICOCHEMICAL AND TECHNO-FUNCTIONAL CHARACTERIZATION OF BLACK MASHUA (TROPAEOLUM TUBEROSUM), AN UNDERUTILIZED ANDEAN TUBER

Black mashua (Tropaeolum tuberosum) is an Andean tuber traditionally used in rural Peruvian cuisine (Manrique et al., 2014) that has attracted increasing interest as a source of bioactive compounds, particularly phenolic compounds associated with antioxidant activity (Behar et al., 2021; Carriel et al., 2023). Its intense dark pigmentation and traditional use highlight its potential for Andean crops valorization as functional food ingredientes (Arteaga-Cano et al., 2022). This study aimed to characterize the bioactive potential of black mashua flour by determining of total phenolic content and antioxidant capacity, complemented by physicochemical and techno-functional characterization. Tubers from Caraz, Ancash, Peru, were washed, sanitized with sodium hypochlorite (100 ppm, 5 min), sliced to 2 mm, blanched at 80 °C for 4 min, dehydrated at 40 °C for 24 h, milled, and vacuum-packed, adapted from González et al. (2020). The resulting flour was characterized for moisture, ash, pH, titratable acidity, reducing sugars, and color parameters (L*, a*, b*, and chroma). Techno-functional properties were evaluated through water absorption capacity (WAC), water absorption index (WAI), and water solubility index (WSI). The bioactive potential was assessed through total phenolic content using the Folin–Ciocalteu method and antioxidant capacity using DPPH, ABTS, FRAP, and ORAC assays. Black mashua flour showed 6.59 ± 0.07% moisture and 4.70 ± 0.05 g/100 g ash, with a pH of 5.31 ± 0.02 and reducing sugars of 33.94 ± 0.17 g. Its color was characterized by low luminosity (L* = 6.42 ± 0.19), with a* = 11.55 ± 0.14 and b* = 11.87 ± 0.11, indicating a dark purple coloration. The flour showed a total phenolic content of 98.68 ± 1.14 g GAE/100 g. Antioxidant capacity reached 68,324.53 ± 3,232.82 µmol TE/100 g by DPPH, 66,119.94 ± 2,472.70 µmol TE/100 g by ABTS, 24,948.74 ± 654.36 mg GAE/100 g by FRAP, and 1,562.79 ± 75.53 µmol TE/100 g by ORAC. The complementary antioxidant assays indicate a marked antioxidant capacity, supporting the bioactive potential of black mashua flour. In addition, the flour exhibited favorable water-related techno-functional properties, with a WAC of 7.85 ± 0.37 g/g, a WAI of 5.95 ± 0.11 g and WSI 10,44 ± 0,10 supporting its incorporation into food matrices. Overall, black mashua flour represents a promising Andean source of bioactive compounds, with measurable total phenolic content, antioxidant capacity, and favorable techno-functional properties, supporting its valorization as a functional food ingredient.

Funding: This research was funded by CONCYTEC and PROCIENCIA under Grant E033-2023-01-BM Phase 2, Contract No. PE501084298-2023-PROCIENCIA, and Grant E077-2023-01-BM, Contract No. PE501094188-2024-PROCIENCIA. Thanks to CNPq for the research scholarship provided to M.S. (312759/2025-8).