Development, characterization and stability of a novel sport drink based on thermal water, apple juice and hibiscus

• Isotonic drink made with thermal water had suitable traits for this product type. • Due to apple juice and hibiscus, the isotonic was rich in phenolic compounds. • The isotonic drink also showed significant antioxidant activity. • It was chemically and microbiologically stable at 4°C and 25°C for 45 days. • Thermal water can be used as a source of electrolytes in isotonic drinks. Isotonic drinks are sports beverages that replenish minerals and rapidly absorbable carbohydrates. We proposed to surpass traditional formulations of isotonic drinks by integrating thermal water, which remains unexploited as a source of electrolytes in isotonic despite the high mineral content. The novel formula combined thermal water with apple juice and hibiscus extract (as sources of sugars and color, respectively, and bioactive compounds). Through comprehensive analysis of chemical, physicochemical, and microbiological properties over 45 days at 4°C and 25°C, the results unveiled an isotonic drink with satisfactory characteristics for this product category: pH of 3.72, 7.93 mg/100 mL of total sugars, and 148.30 mg/100 mL minerals, predominantly sodium (34.99 mg/100 mL) and potassium (73.20 mg/100 mL). It showed significant phenolic compounds, notably chlorogenic acid (2.75±0.10 mg/100 mL), and antioxidant activity (472.72 µmol Trolox eq/100 mL). It maintained a vibrant red hue derived from hibiscus anthocyanins (delphinidin 3- O -sambubioside and cyanidin 3- O -sambubioside, totaling 4.06±0.03 mg/100 mL), and demonstrated microbiological stability throughout the storage period in both temperatures studied. Therefore, by harnessing the potential of thermal water, this study paves the way for a novel approach to developing sports beverages and can serve as a model for countries rich in thermal springs.