## 3 Results and Discussion
After dehydration, powdered beverages should retain the color, flavor, and nutritional value of the  
Figure 1: Consumer quality of powdered beverages: A—rehydration at 20 \({}^{\circ}\)C; B—rehydration at 80 \({}^{\circ}\)C; MO1—control beverage; MO2—beverage enriched with 10% raspberry; MO3—beverage enriched with 10% strawberry; MO4—beverage enriched with 10% apple; MO5—beverage enriched with 5% raspberry and 5% strawberry; MO6—beverage enriched with 5% raspberry and 5% apple; MO7—beverage enriched with 4% apple, 3% raspberry, and 3% strawberry;. raw materials [12]. Knowledge of the rehydration properties of lyophilized ingredients can contribute to improvement of the quality of ready-to-drink products. The color parameters of rehydrated samples are presented in Table 2. In general, the color of each beverage was very similar, and only slight differences in individual parameters were noted. All drinks had the same base (90%), the content of which dominated in the final color of the individual samples. The color coordinates of MOI indicated that the additives had a slight influence on the lightness (L*) of the beverages. In the case of beverages rehydrated at the lower temperature, the minimum value for L* (31.50) was obtained for MO4, whereas the maximum value of this parameter (33.03) was found for the sample with the 10% addition of apple and strawberry. The color component a* (redness) changed across a rather narrow range from 6.59 (control sample) to 9.61 (sample with the 10% addition of apple and strawberry). The redness of MO1 (control beverage) was significantly lower compared to that of the drinks with the addition of fruits. The values for yellowness (b*) ranged from 12.53 (MO7) to 14.68 (MO4). Except MO4, the yellowness of the control beverage (MO1) obtained at 20 \({}^{\circ}\)C was significantly higher compared to the other beverages. The loss in the b* value indicates that the yellowness of the sample decreased when the functional lyophilates were added. It may also be related to partial decomposition of carotenoids and generation of brown pigments. An opposite result was found for samples rehydrated at 80 \({}^{\circ}\)C, where the functional additives significantly increased the yellowness of the beverages. The rehydration at the higher temperature resulted in a slight decrease in the pH value. The pH of the cold drinks ranged between 5.16 and 6.22, while those rehydrated at 80 \({}^{\circ}\)C had a pH value from 4.99 to 5.92. It may be suggested that organic acids were better soluble at the higher temperature, which was previously confirmed in the study of [PERSON] and [PERSON] [52] on steamed carrot and pumpkin. There were slight differences in the WAI and WSI parameters in the powdered beverages; however, they did not exceed 10%. The loose porous structure of dried materials makes water penetration easy; hence, it can be expected that the rehydration in hot water may help to release bound compounds and cause decomposition of the main compounds responsible for the color parameters. On the other hand, tissue structure disruption and technological procedures were found to cause degradation of natural colorants. [PERSON] and [PERSON] [51] reported a high correlation between color changes and carotenoid content in pumpkin powders. The degradation of carotenoids was shown to be mainly induced by temperature and oxygen.