## 3 Results and Discussion  
### ABTS\({}^{\bullet+}\) Radical Scavenging Capacity and Phenolic Content of Spice Extracts  
The ABTS\({}^{\bullet+}\) radical scavenging activity of 7 plant extracts is shown in Table 1. Among tested spices, cloves were characterized by the highest antioxidant activity with the TEAC value of 2496 uM/g. The radical scavenging capacity of extracts from allspice and bay leaf was 3-fold and 9-fold lower, respectively, when comparing to cloves. Nutmeg, caraway, black seed and cardamom with the TEAC values ranged from 45 to 13 uM/g formed the group of spices with the lowest antioxidant activity. Our results are in agreement with the study of [32] who showed that the ABTS\({}^{\bullet+}\) radical scavenging capacity of the extracts from cloves and allspice were very high with the TEAC values of 2071 and 719 uM/g, respectively. In this study, the rank of radical scavenging capacity of extracts provided by the TEAC assay was as followed: Cloves \(>\) allspice \(>\) bay leaf \(>\) nutmeg \(\geq\) caraway \(\approx\) black seed \(\geq\) cardamom and was the same as the rank of DPPH radical scavenging activity and similar to the rank provided by the FRAP assay, both showed in our previous paper [13].  
High positive [PERSON]'s correlation coefficients were observed between the results of TEAC and DPPH methods (r = 0.997 at \(p\) = 0.000, Student's t test) and TEAC and FRAP methods (r = 0.998 at \(p\) = 0.000, Student's t test). As it was shown previously [13] the antioxidant activity of spice extracts resulted from their phenolic content. For the correlation of ABTS\({}^{\bullet+}\) radical scavenging activity of spice extracts with their total polyphenol content (from [13]) the r Pearson's coefficient was 0.988 (at \(p\) = 0.000, Student's t test).  
Table 2 includes the results of UPLC analysis of phenolic acids and some polyphenols in spice extracts. The highest content of phenolic acids was observed for clove extract. Surprisingly, levels of compounds in allspice extract quantified by UPLC was very low despite showing high total polyphenol content measured by [PERSON]'s methods [13]. However, significant correlation was noticed between total phenolic acids by UPLC (Table 2) and the TEAC values (Table 1) of extracts, with r Pearson's coefficient equaled to r = 0.81 (\(p\) = 0.027, Student's t test).  
Generally, the direct comparison of phenolic content of extracts with the literature data was difficult, since huge variations were observed in the qualitative and quantitative characteristics of spice extracts reported by others [33; 34; 35]. These differences could be attributed to the genotypic and environmental differences within species, sample preparation and determination methods.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Extracts** & **TEAC (ABTS) uM/g** \\ \hline Nutmeg & 44.80 \(\pm\) 1.93 d \\ Allspice & 815.37 \(\pm\) 20.85 b \\ Bay Leaf & 280.03 \(\pm\) 21.51 c \\ Black seed & 33.06 \(\pm\) 2.79 de \\ Cloves & 2495.85 \(\pm\) 31.41 a \\ Caraway & 35.37 \(\pm\) 0.39 de \\ Cardamom & 12.93 \(\pm\) 0.46 e \\ \hline \hline \end{tabular} All values are mean \(\pm\) SD of the three replicates. (a–e) means with the same superscript are not different (\(p\) \(>\) 0.05, Duncan’s test).  
\end{table}
Table 1: ABTS\({}^{\bullet+}\) radical scavenging activity of spice extracts.