Isotonic Drinks Based on Organic Grape Juice and Naturally Flavored with Herb and Spice Extracts

The aim of this study was the elaboration of isotonic drinks rich in bioactive compounds and antioxidant activity using organic ingredients and without synthetic additives. Grape juice was used as a natural source of sugars and phenolic compounds, combined with lemon juice and natural flavors from herb and spice extracts. The ingredients were diluted in two types of water with different mineralization, to which three different determined concentrations of salts (sodium chloride and potassium chloride) were added. The beverages had a sugar content ranging from 72.73 ± 0.23 to 78.43 ± 0.06 g/L, total soluble solids between 4.23 ± 0.06 and 4.83 ± 0.29 °Brix, and total acids from 1.75 ± 0.02 to 2.39 ± 0.08 g/L. Generally, antioxidant activity was higher in the beverages flavored with herb and spice extracts, ranging from 3.28 ± 0.01 to 4.27 ± 0.09 µmols Trolox equivalent/mL. Color intensity showed an increase of up to 129.39% in all samples during the storage period, being higher in beverages prepared with high-mineral water and having high pH values. The results of sensory analysis revealed that the flavored beverages had higher values of global perception than the controls. Thus, the functional properties of grape juice have been increased, and these beverages can be alternative natural and healthy products because their formulation is based only on organic and natural ingredients.