## 3 Results and Discussion
### Antioxidant Capacities
The evaluation of bioactive substances of presently investigated fruits, including polyphenols, tannins, flavanols, flavonoids, vitamin C and antioxidant capacities (Table 1) well agreed with the data, discussed in recent investigations [39; 45; 46]. A positive and highly significant correlation between the contents of total phenols and radical scavenging capacities against all used radicals, and especially against ABTS and DPPH in persimmons, are in line with described data [21]. Binding Properties of Bioactive Compounds of Investigated Fruits with Serum Protein Measured by Fluorescence  
The results of changing in the fluorescence intensity during interaction of polyphenols with HSA are shown in Tables 1 and 2 and Figure 2. For the standards were chosen gallic acid and epicatechin. The quenching of polyphenols extracted from persimmon 'Fuyu' and kiwifruit 'Hayward' were in the same range and were comparable with gallic acid and among other kiwifruit cultivars were the lowest. As it was described previously [1; 2; 5], the quenching of the protein depends on the amount of the fruit extract added to the reaction, then fluorescence intensity decreases, by the shifting in the emission value. The change of the fluorescence intensity after interaction with HSA was compared with HSA before interaction, and the peaks **a** and **b** were measured, and the binding properties were calculated. The binding properties measured by 2D-FL (Table 2) differ from the values estimated by 3D-FL (Table 1, Figure 2). In 3D-FL the main changes were found according to the decrease of fluorescence intensity mostly in peak **a**. The results showed that the binding properties of 'Bidan' were greater than other investigated fruits and estimated of about 51%, according to the changes in the fluorescence intensity of peak **a** (Table 1). Binding properties of 'Hayward' and 'Fuyu' were comparable and showed 18% and 14%, respectively (Table 1, Figure 2). The high binding properties of the investigated fruits can be explained by their antioxidant capacities. The antioxidant capacities of 'Bidan' by DPPH and ABTS assays were 4.2 times greater than for 'Hayward' and the binding properties of 'Bidan' were also greater than for 'Hayward' by 2.8 times (Table 1). These results are in full agreement with the correlation analysis which demonstrated that the phenolic and flavonoid contents are responsible for increasing the scavenging activities of DPPH and ABTS, where protocatechuic and chlorogenic acids were the predominant phenolic acids in kiwifruit pulp, as well as gallic acid, epicatechin, and catechin [47]. The fluorescence results indicate that there was a static quenching mechanism in the interactions of gallic acid (GA) with BSA [48] and support the data obtained in Table 2, where the binding properties of gallic acid were slightly higher that for kiwifruit 'Hayward'. Epicatechin showed as well relatively high binding properties which were closed to the ability of kiwifruit _A. Arguta_ (Table 2). These results are consistent with others [49], where the interaction of copper complexed with (-)-epigallocatechin-3-gallate (EGCG)