## 4 Discussion
Based on this study, it is indicated that mousses are a rich source of vitamin C. Its content significantly affects the measurement of phenolic compounds, as the Folin-Ciocalteau reagent reacts with ascorbic and dehydroacorbic acid (DHA) and reducing sugars, often providing overestimated results [41]. The vitamin C content of fresh fruit mousses ranged from 5.88 mg/100 g to 16.66 mg/100 g, while in the study by [PERSON] et al. [40] the range of ascorbic acid content was much wider (1.9-71.5 mg/100 g). However, in these authors' study, some of the mousses contained synthetically added vitamin C. Analyzing the content of vitamin C from fruit only, it is indicated that the highest level is similar to the vitamin C content obtained in our study for multi-components mousses. Because of the most varied ingredients, the multi-components mousses (M1, M2, M3, and M4) contained the highest amounts of vitamin C. Multi-components mousses contained 30% strawberries, which are an excellent source of ascorbic acid [42]. In the single-component mousses (apple and pear mousses), the level of vitamin C varied among producers, which may be due to the type of fruit, its origin, and the state in which the fruit was before thermal processing [43]. In fresh mousses, vitamin C levels were positively correlated with TPC, TFC, and AC. The studied mousses were analyzed for AC by the DPPH assay. The multi-component mousses (M1, M2, M3, and M4) had the highest ability to capture oxygen free radicals, due to their diverse composition. It should be noted that they were also characterized by the highest TPC. These mousses have a more varied composition relative to apple and pear mousses, which may result in a higher concentration of antioxidants [12; 44]. [PERSON] and [PERSON] [45] indicated a significant relationship between the antioxidant properties and the species of fruits and vegetables completing the composition of mousses. [PERSON] and [PERSON] [12] indicate higher values of antioxidant properties in mousses with a more diverse composition than in those with a lower variety. It should also be noted that, in this study, only DPPH, an organic solvent-soluble radical, was used to determine antioxidant properties. Because some of the antioxidants will not be detected by the DPPH assay, the result of the total AC may be underestimated [46; 47]. The correlation results show a strongly positive correlation between the TFC and DPPH, and a positive correlation between DPPH and TFC and DPPH and vitamin C.  
Because fruit and vegetable mousses are dedicated especially to infants and young children, it is important to store them properly according to the manufacturers' storage instructions on the product label [2; 4; 48]. Losses of vitamin C in fruit products can cause deficiencies and their resulting health consequences. An important aspect is to provide adequate vitamin C to the diet to ensure optimal health and support the immune system [49]. In general, ascorbic acid deficiencies are relatively rare in children due to its prevalence in the diet, especially its presence in fruits and vegetables [50]. In addition to supporting immune function, vitamin C is also a strong antioxidant and aids in iron absorption. Symptoms of vitamin C deficiency include a weakened immune system, skin problems, and scurvy in cases of severe deficiency [51]. The results of the studies have shown a significant decrease in compounds from the antioxidant group--phenolics, flavonoids, and vitamin C, as well as AC. Fruit mousses are preserved by pasteurization, which effectively ensures the safety of the product. However, the manufacturer recommends storing the mousses after opening for a maximum of 48 h at refrigerated temperature [2]. After this period of refrigerated storage, there was a significantly lower loss of bioactive compounds in the fruit mousses compared to storage at room temperature. The relatively high losses of bioactive compounds in the mousses could also be caused by the lack of added saccharose in the products.