# Osmolality of Components and Their Application in the Design of Functional Recovery Drinks
## 3 Results and Discussion
### Determining the Composition and Physico-Chemical Properties of Recovery Drinks  
The composition of five fruit juice drinks intended for body regeneration after intensive physical exercise was established, based on the recognized relationships between osmolality and concentrations of electrolytes (Na\({}^{+}\) and K\({}^{+}\)), citric acid, and blackcurrant powders obtained by the two methods (i.e., freeze-drying and spray-drying), as well as accounting for the literature data (Table 1). It was assumed that CHO-electrolytes designed compositions should ensure the body's adequate hydration after intensive physical exercise, whilst delivering sufficient calories required for regenerating the body derived from CHOs contained within the powdered formulations, along with the added glucose and sucrose. Furthermore, the blackcurrant powders contain high levels of antioxidants such as polyphenols and vitamin C [30] that ameliorate the effects of oxidative stress brought upon by excessive physical exertion. They are an important source of nutrients for the body's needs and can also act as supplements. The fruit powder content for powders obtained by the spray-dried method ranged from 6 to 7%, whilst this was 3 to 4% for the freeze-dried ones; this respectively corresponded to an equivalent 16 to 18% and 19 to 25% content when taking fresh fruit or blackcurrant juice into consideration. The spray-dried method gave a 60% lower juice content because 60% maltodextrin carrier is used for the preparation [30]. These aforementioned contents used in the designer drinks were established by pilot testing, taking an assumed total sugar content to provide an acceptable level of taste and appropriate osmolality. Greater amounts of powders added than those shown in Table 1 degraded the drink taste, which had to be counteracted by adding more CHOs. The CHO content of the designed drinks that included fruit powders and glucose or sucrose respectively ranged from 7.2 to 8.1% (after conversion taking into account the content of the soluble solids content and the total content of acids). These CHO values are comparable to those found in commercially available recovery beverages (ranging from 9.1 to 18.0 g/100 g of drink) [11]. Functional beverages designed for athletes in order to enhance rehydration rates and delay fatigue should contain 40 to 80 g/L of CHOs (optimally 60 to 80 g/L) [7]. CHO amounts greater than 80 g/L in drinks may, however, slow gastric emptying and reduce intestinal water absorption during exercise when compared to beverages with lower CHO concentrations [7; 22]. Electrolytes, NaCl and KCl, added to the designed beverages gave respective concentrations of 0.1 to 0.2% (400 to 800 mg Na\({}^{+}\)/L) and 0.025% (130 mgK\({}^{+}\)/L), which were consistent with levels found in such drinks in other studies [3; 7; 22]. [PERSON] and [PERSON] (1997) [7] state that sodium content should be higher than 400 mg/L (optimally >600 mg/L) and the recommended maximum content values for Na+ and K+ are, respectively, 1100 and 225 mg/L. Measured osmolalities, ranging from 401 to 564 mOsm/kg H\({}_{2}\)O, are presented in Table 2, along with those calculated from regression equations based on results obtained from individual drink components such as fruit powders, electrolytes, and CHOs. The obtained osmolality values were significantly different (\(p<0.05\)) for each drink designed. Drink version 3, which had low levels of  
Figure 4: Blackcurrant freeze-dried (a) and spray-dried (b) powder osmolalities in aqueous solution. added glucose (1%) and 7% spray-drying blackcurrant powder, gave the lowest osmolalities. The drink versions 2a and 2b had the same level of added ingredients and differed in the type of sweetener added (version 2a glucose; version 2b sucrose). These drinks differed in osmolality, drinks with added sucrose had significantly lower osmolality values. Maltodextrin has lower osmolalities than glucose and sucrose and can be used in amounts up to 10% in recovery drinks designing [7].