## 3 Results
### Storage Influence on Total Phenolic Content and Antioxidant Properties of Designed Confectionery  
The samples of chocolate with an addition of yellow tea extract were tested for antioxidant activity in free radical tests (DPPH\({}^{\bullet}\) and ABTS\({}^{\bullet\star}\)) and ORAC test during 6 months of storage at ambient temperature. The obtained results are presented in Figure 4. DPPH\({}^{\bullet}\) and ABTS\({}^{\bullet\star}\) as stable radicals are widely used to evaluate the antioxidant activity of various compounds and thus acting as antioxidants [62]. All analyzed samples showed higher activity in DPPH radical scavenging compared to ABTS assay. The highest activity toward radical, measured in Trolox (Tx) equivalents, was found in samples of dark chocolates, which were found to differ significantly between other samples (\(p<0.05\)). The results demonstrate that the addition of yellow tea extract powder was a successful attempt at increasing the antioxidant potential of enriched chocolates. The highest activity in scavenging the DPPH radical was determined for the samples of dark chocolate with yellow tea (4373 mg Tx/100 g) and the control sample (4012 g of Tx/100 g). The lowest activity was found for the control sample of white chocolate (23 mg Tx/100 g) and white chocolate with yellow tea extract (100 mg Tx/100 g). Among the samples of chocolates, a decrease in anti-radical activity was observed with the storage time (\(p\leq 0.05\)). The DPPH radical scavenging activity decreased the most in samples stored for 6 months without the addition of yellow tea, and by 87% for WCC, 37% for MCC, and 29% for DCC. In the chocolates with the addition of yellow tea extract, the above decrease in anti-radical activity was significantly lower (\(p<0.05\)) and amounted to 5% (MCT), 13% (DCT) and 14% (MCT). ABTS radical cation scavenging activity showed the opposite trend compared to DPPH assay within examined samples. The highest activity was determined for the samples of dark chocolate with yellow tea (386 mg Tx/100 g) and without additive (285 g of Tx/100 g). The lowest activity was found for the white chocolate (3.7 mg Tx/100 g) and white chocolate with yellow tea extract (30 mg Tx/100 g). The storage time of chocolate samples resulted in the significant increase of anti-radical activity (\(p<0.05\)). The ABTS radical scavenging  
Figure 4: Antioxidant activity of white, milk and dark chocolate extracts with 0.2% addition of yellow tea extract during storage. activity increased the most in samples stored for 6 months with the addition of yellow tea, and amounted to 43% for MCT, 14.8% for WCT, and 12.8% for DCT. In the chocolates without the addition of yellow tea extract, decrease in anti-radical activity was evaluated (64% for WCC, and 56% for MCC), only in dark chocolate an increase of 34% scavenging activity was noticed. The highest ORAC value was evaluated for the samples of dark chocolate with yellow tea (4363 uM Tx/100 g) and without additive (4403 uM of Tx/100 g). The lowest value was found for the white chocolate (107 uM Tx/100 g) and white chocolate with yellow tea extract (110 uM Tx/100 g). The results showed no significant loss of oxygen radical scavenging ability during 6 months of chocolate samples storage (\(p>0.05\)). Stable oxygen radical absorbance capacity could be a result of beneficial confectionery product composition which, besides yellow tea leaves extract, also included cocoa butter and cocoa solids, known for their high antioxidative potential [14]. Summarizing, the highest antioxidant activities were evaluated for the chocolates supplemented with 0.2% of yellow tea extract, at both DPPH and ABTS assay, however no changes were present in ORAC assay, regardless of chocolate kind and 6 months of storage. Therefore, it was noticed that yellow tea extract increased the amount of compounds reacting with Folin-Ciocalteu phenolic reagent, which may indirectly indicate antioxidant activity.