# Osmolality of Components and Their Application in the Design of Functional Recovery Drinks
###### Abstract  
Measuring the osmolality of electrolytes, carbohydrates, and other components that contain them, can be very helpful in the design of functional recovery drinks. This study aimed to develop functional recovery drinks based on natural fruit components with the addition of electrolytes and carbohydrates to improve water and electrolyte balance and provide energy after intense physical exertion, as well as ensuring a high content of bioactive ingredients and being of a good sensory quality. The study material consisted of blackcurrant fruit powders obtained by freeze-drying and spray-drying, along with other components such as electrolytes and carbohydrates. The osmolality of the fruit components was measured in aqueous solutions with concentrations from 2.5 to 10%, as well as electrolytes at 0.1 to 4.0% and carbohydrates from 1 to 30%. The sensory quality of drinks was assessed using a scaling method. The content of polyphenols and antioxidant properties were measured spectrophotometrically and the vitamin C content by high-pressure liquid chromatography. Based on the obtained results, five versions of recovery drinks were prepared of defined compositions. These drinks contained fruit powders ranging from 3 to 7%, glucose at 1 to 5%, sucrose 5%, and added electrolytes ranged 0.1 to 0.2% for NaCl and KCl at 0.025%. Their osmolalities ranged from 401 to 564 mOsm/kg H\({}_{2}\)O, the total polyphenol content was 43 to 62 mg GAE/100 mL, and vitamin C 26 to 35 mg/100 mL. All drinks possessed satisfactory sensory quality. It was established that it is possible to obtain fruit recovery drinks containing defined amounts of electrolytes, carbohydrates, and osmolality values recommended for this type of drink. osmolality; fruit powders; recovery drinks 202020  
glycogen breakdown rates in the liver and muscle [7; 8; 9; 10]. When there is an insufficient fluid intake, sweating becomes also limited which at high ambient temperatures may cause the body to overheat. Any ongoing dehydration generally may constitute a threat to health and performance capacity will become reduced. Controlling the body's hydration status is thus very important. The two predominant factors that lead to premature fatigue are depletion of the body's carbohydrate reserves and losses of water and electrolytes via sweating. Being appropriately hydrated is, therefore, necessary to ensure that the body functions efficiently when engaged in sporting activities through consuming beverages of suitable osmolalities intended for sportspersons; the main purpose being to replenish any electrolytes lost during exercise, supplying carbohydrates, preventing dehydration, and sustaining endurance capacity [3; 4; 5; 6; 11]. Isotonic drinks have osmolalities ranging from 275 to 295 mOsm/kg water and are of similar osmotic pressure to body fluids. There are also various other \"light\" sugar-free drinks/mineral waters with osmolalities lower than 275 mOsm/kg water which are termed \"hypotonic\". Unlike isotonic beverages, these are however unable to quickly improve water-electrolytes because of their lower electrolyte concentrations. Hypotonic drinks are in fact recommended for people performing moderate work or those engaging in not too intensive physical exercise nor of long duration without any excessive sweating. Current oral rehydration therapy guidelines suggest that hypotonic carbohydrate (CHO)-electrolyte solutions should be drunk whenever there is a need for rapidly replacing fluid [12; 13; 14]. If, however, the aim is to maintain fluids balance over prolonged periods, then drinking such hypotonic CHO-electrolyte solutions may be inappropriate because of differences in urine volume excreted. Electrolytes, especially sodium, play a major role in fluid homeostasis where the amounts of sodium and chloride lost through excretion are relatively large compared to losses in magnesium, calcium, and potassium.