# Shaping the Properties of Osmo-Dehydrated Strawberries in Fruit Juice Concentrates
## 3 Results and Discussion
### The Impact of Fruit Concentrates on the Chemical Properties
Thus, new ways of preserving or enriching them are needed. Fresh strawberries were characterized by the content of anthocyanins at the level of 20.9 mg Cyd-3-glu/g d.m. Statistical analysis showed a significant effect of the type of osmotic agent (\(p<0.05\)) and no effect of the processing time (\(p>0.05\)) on the content of these compounds in osmotically dehydrated strawberries (Figure 6). In strawberries osmotically dehydrated in a chokeberry juice concentrate, their content significantly increased to about 32.9 mg Cyd-3-glu/g d.m. Additionally, when sour cherry was subjected to osmotic dehydration in an apple juice concentrate mixed with a sour cherry juice concentrate it resulted in a higher content of anthocyanin than the samples dehydrated in a sucrose or apple juice concentrate. This was connected with the cherry juice uptake during the osmotic dehydration process [15]. In the case of strawberries dehydrated in a sucrose solution, the content of anthocyanins decreased by half (49%). The use of strawberry juice concentrate reduced these losses to about 27% and the use of cherry juice concentrate reduced these losses to about 5%. Chokeberry fruit, therefore also juice concentrate, is a rich source of anthocyanins [49]. Using a chokeberry juice concentrate for the osmotic dehydration of strawberries may be particularly beneficial for producing the so-called soft snacks with reduced moisture IMF (intermediate moisture food) and health-promoting features. Figure 7 presents the effect of the type of osmotic agent on the antioxidant activity of osmodehydrated strawberries. The ABTS test gave a lower antioxidant capacity than the DPPH test. According to [PERSON] [50], the ABTS radical measured the antioxidant capacity of hydrophilic and lipophilic compounds and the DPPH of hydrophobic compounds. Statistical analysis showed a significant effect of the type of osmotic agent (\(p<0.05\)) and no effect of dehydration time (\(p>0.05\)) on the radical scavenging activity for DPPH and ABTS radicals. Since the DPPH and ABTS values were varied and, depending on the osmotic agent used, they increased, decreased, or were constant in the range of 0.5-3 h of dehydration, their average values over this time range were compared. Strawberries subjected to a sucrose solution and a cherry juice concentrate were characterized by, respectively, 24.4-34.2% and 19.4-33.7% lower values of antioxidant activity than fresh strawberries. However, for strawberries dehydrated in chokeberry and strawberry juice concentrates the values of both indicators were found to be 1.3-5% higher. Similar effects were observed for carrots and zucchini [7] and for apples [13], where the increase  
Figure 6: Effect of the type of osmotic agent (sucrose and fruit concentrates) on the total polyphenol content and anthocyanin content in osmodehydrated strawberries. Different letters (small letters are for anthocyanin content, capital letters are for total polyphenol content) above columns show the statistical difference (\(p<0.05\)). of antioxidant activity was observed with the increasing time of osmotic dehydration in chokeberry juice. The FTIR spectra of the solutions (Figure 8a), as well as samples after osmotic dehydration (Figure 8b), were conducted in order to compare changes in the chemical structure of strawberries dehydrated in different osmotic agents. As can be seen from Figure 8, the osmotic solutions, as well as strawberries dehydrated in sucrose and juice concentrates, were characterized by the similar vibrational modes of molecules in the samples, allowing for the identification of functional groups and chemical compositions. In the case of the osmotic solutions, the lower absorbance of the vibration (Figure 8a) was observed in comparison with strawberries subjected to the osmotic dehydration in those solutions (Figure 8b). Differences between the samples were observed mainly in the area between the wavenumber range of 1800-600 cm\({}^{-1}\) and in the area of the C-H and O-H groups at 3500-2800 cm\({}^{-1}\)[51].