# Shaping the Properties of Osmo-Dehydrated Strawberries in Fruit Juice Concentrates
## 3 Results and Discussion
### The Impact of Fruit Concentrates on the Chemical Properties  
3.1 The Influence of Fruit Concentrates on the Bioactive Compounds in Osmotically Dehydrated Strawberries  
Vitamin C was evaluated with ultra-performance liquid chromatography. In the fresh strawberries, vitamin C content is equal to 235.8 \(\pm\) 5.7 mg/100 g d.m. (Figure 5). Due  
Figure 4: Microstructure (200\(\times\) magnification) of fresh strawberries osmotically dehydrated for 3 h in solutions of sucrose, chokeberry (chok juice), strawberry (straw juice), and cherry juice concentrates. to the high thermolability and solubility, the vitamin C content in 3 h dehydrated fruit was significantly lower compared with the raw material. Statistical analysis showed that the content of ascorbic acid in fresh strawberries was statistically higher than in samples subjected to osmotic dehydration. The highest value of vitamin C was found in fruits dehydrated in the strawberry juice concentrate solution (220.48 \(\pm\) 3.62 mg/100 g d.m. ), while the lowest (65.60 \(\pm\) 3.03 mg/100 g d.m.) was found in strawberries dehydrated in a sucrose solution, as expected. The statistical analysis showed a significant difference in the content of ascorbic acid between strawberries dehydrated in the strawberry juice concentrate solution and solutions of chokeberry, cherries, and sucrose. During the osmotic dehydration, mass transfer occurs and bioactive compounds contained in the juice concentrate solution penetrate the tissue of the raw material. On the other hand, the raw material loses its valuable substances as a result of leaching into the osmotic solution. Strawberry is rich in vitamin C [1], therefore the material dehydrated in the strawberry concentrate solution recorded the highest content of this vitamin. The low content of vitamin C in the strawberries dehydrated in the sucrose solution and juice concentrates, in this case, chokeberry and cherries, results from the low or lack of content of these compounds in them. The literature data show that chokeberry fruits contain about 2.4 mg/100 g of fresh fruit [36], cherries 62.4 mg/100 g of fresh weight (f.w. ), and strawberries 90.1 mg/100 g f.w. [3]. Juice concentrates probably contained vitamin C in proportion to these amounts; therefore, in dehydrated strawberries, high content was found only with the use of a strawberry juice concentrate. The content of total polyphenols in chokeberry fruits is about 2919.4 mg/100 g d.m. [7], in cherry fruit about 314.4 mg/100 g f.w. [3], which may correspond to about 3000 mg/100 g d.m., and in strawberries (our research) about 1743 mg of chlorogenic acid/100 g d.m. The total content of polyphenols in fresh strawberries was about 1743 mg of chlorogenic acid/100 g d.m. (Figure 6). The content of polyphenols in osmotically dehydrated fruits differed significantly depending on the type of osmotic agent used (\(p<0.05\)). However, there was no effect of dehydration time on the value of this index (\(p>0.05\)). Nevertheless, [PERSON] et al. [7] noticed that, with a longer time of osmotic dehydration in chokeberry juice for carrot and zucchini, changes were statistically significant only for zucchini. The use of a sucrose solution and cherry concentrates resulted in a decrease in polyphenol content by about 6%. On the other hand, osmotic dehydration of strawberries in chokeberry and strawberry juice concentrate increased the content of these compounds by about 1 and 10%, respectively. However, all these changes were not statistically significant, so it can be noticed only as a trend. Figure 5: Effect of the type of osmotic agent (sucrose and fruit concentrates) on the vitamin C content in osmodehydrated strawberries. Different letters above columns show the statistical difference (\(p<0.05\)). Anthocyanins give fruits their color from blue to purple and red to orange. They have a positive (pro-healthy) effect on the functioning of the body, but, due to the action of oxygen, light, temperature, and other factors, they are degraded [30].