CONTROLLED GERMINATION EFFECT ON THE TOTAL PHENOLIC CONTENT AND ANTIOXIDANT CAPACITY OF RED QUINOA (CHENOPODIUM QUINOA WILLD.) CV. PASANKALLA

Quinoa (Chenopodium quinoa Willd.) is an Andean pseudocereal recognized for its nutritional value and bioactive compounds associated with antioxidant activity (Zurita-Silva et al., 2014).  Germination is a bioprocessing strategy that can induce biochemical changes in the grain and modify the expression and availability of compounds of functional interest. However, these changes may depend on genotype, germination conditions, elicitors, and the method used to assess antioxidant activity. (Paucar-Menacho et al., 2018; Guardianelli et al., 2022). This study aimed to evaluate the effect of germination on the phenolic profile and antioxidant capacity of red quinoa cv. Pasankalla, complemented by the assessment of its physicochemical and techno-functional properties. Seeds from Ayacucho, Peru, were disinfected with 0.01% sodium hypochlorite for 30 min, washed to reach neutral pH, soaked at a 1:5 (w/v) ratio for 6 h, and germinated at 20 °C for 42 h under 80% RH (Paucar-Menacho et al., 2018). Germinated and ungerminated samples were subsequently dehydrated, milled, and vacuum-packed. Total phenolic content was determined using the Folin–Ciocalteu method, while antioxidant capacity was assessed using DPPH, ABTS, FRAP, and ORAC assays. Germination produced differential changes in the bioactive indicators. Total phenolic content decreased from 4.27 ± 0.08 to 3.58 ± 0.16 mg GAE/g, while DPPH antioxidant capacity decreased from 641.62 ± 14.92 to 392.52 ± 17.56 µmol Trolox/100 g. In contrast, ABTS increased from 3728.25 ± 124.22 to 6437.69 ± 187.77 µmol Trolox/100 g, whereas FRAP increased from 629.79 ± 14.23 to 722.79 ± 26.41 µmol trolox//100g and ORAC from 625.11 ± 26.63 to 799.29 ± 13.55 µmol Trolox/100 g after germination (P< 0.05). These results indicate that germination modified the antioxidant response of red quinoa in an assay-dependent manner, suggesting changes in the composition or availability of compounds with antioxidant capacity. As a complementary response, germination also modified the techno-functional properties, with a decrease in the water absorption index from 4.57 ± 0.20 to 2.91 ± 0.13 g/g and an increase in the water solubility index from 4.15 ± 0.11 to 16.87 ± 0.82%. Overall, germination modified total phenolic content and antioxidant capacity of red quinoa cv. Pasankalla, with contrasting responses among antioxidant assays, supporting germination as a bioprocessing strategy for producing ingredients with differentiated bioactive characteristics. These findings contribute to the valorization of germinated quinoa for the development of foods with functionality associated with bioactive compounds.

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. Thans to CNPq for the research scholarship provided to M.S. (312759/2025-8).