Coconut Water Based Isotonic-Drink for Athletes: By-Product Utilization of the Copra Industry

Abstract

Isotonic drinks are quick and the best way to replace the energy and fluid losses of athletes; which need to have salt and sugar concentrations similar to those in human body fluids. The sugar substrate is principally represented by the mono or disaccharides, and electrolytes have a key function to maintain the osmolality same as the human blood which is important to compensate for nutrient losses in athletes. Thus, the study targeted to formulate the coconut water based isotonic drink. 84.04% of coconut water was used and different formulations were prepared with varying carbohydrate composition. 1.25% of both D-glucose and maltodextrins containing citrus-flavored formula received the highest preference scores from the 30 un-trained sensory panelists and has fortified by amino acids such as leucine: isoleucine: valine in a 2:1:1 ratio according to literature. The osmolality, pH, titratable acidity, total soluble solids, browning index, and turbidity of the formulated isotonic drink were 328 mOsm/L, 3.42 ± 0.012, 0.28 ± 0.016%, 7.43 ± 0.0570, 0.06 ± 0.006 and 162.67 ± 0.577 NTU, respectively. The total sugar content, energy value, and ascorbic acid content of the formulated isotonic drink were 7.2 ± 0.451 g/100 mL, 25.26 ± 0.213 kcal/100 mL, and 52.86 ± 0.896 mg/100 mL; the color was expressed as L, a* and b* values as 58.6 ± 1.496, -0.62 ± 0.016 and 4.18 ± 0.427, respectively. Total phenol content and IC50 value for DPPH radical scavenging activity were as 31.33 ± 0.40 GAE mg/ mL, and 0.91 ± 0.016 mg/mL, respectively. Physicochemical properties such as total sugar content, sodium content, and osmolality have complied with the international standards and the expected shelf life was 6 months. In conclusion, isotonic drinks can be effectively formulated by using coconut water and have proven functional and unique organoleptic properties.