Sweetening with Agavins: Its Impact on Sensory Acceptability, Physicochemical Properties, Phenolic Composition and Nutraceutical Potential of Oak Iced Tea

Oak infusions enriched with agavins may offer nutraceutical benefits in the development of iced teas. This study evaluated infusions of <i>Quercus sideroxyla</i> and <i>Quercus eduardii</i> leaves formulated with different concentrations of agavins (0, 2, 6, and 10%), analyzing their physicochemical and sensory properties, chemical stability, and antioxidant capacity. The incorporation of agavins resulted in substantial modifications to physicochemical parameters, including pH, titratable acidity, and soluble solids, thereby enhancing product stability and consistency. Notable distinctions were observed between the two species with respect to their acidogenic response and soluble solid concentration. Interactions between agavins and phenolic compounds, as discerned by UPLC-PDA-ESI-MS/MS and FT-IR, exerted a significant influence on bioactivity of the phenolic constituents, thereby affecting the nutraceutical potential of the infusions. These interactions, facilitated by hydrogen bonds, led to reduction in phenolic acids, such as quinic acid (↓ 43%), and alteration in antioxidant capacity at high concentrations of agavins. The findings underscore the significance of meticulously designing balanced formulations that optimize chemical stability, functionality, and sensory acceptance, thereby ensuring the quality of the final product.