# The Effect of Hydrolysis on the Antioxidant Activity of Olive Mill Waste
## 3 Results
### Antioxidant Activity
#### 3.2.2 Metal Ion Reducing Activity  
The highest metal ion reducing activity for FRAP and CUPRAC assays were both found in alkaline hydrolysis. Figure 6 shows that CUPRAC under both acidic and alkaline hydrolysis, Bella di Spagna had the highest concentration (acid: 15.47 \(\pm\) 1.09 and alkaline: 25.22 \(\pm\) 0.49), whilst the lowest reducing activity was found in Leccino (acid: 6.33 \(\pm\) 0.36 and alkaline: 5.33 \(\pm\) 0.25). For methanolic extracts, the highest reducing activity was found in Leccino (15.02 \(\pm\) 1.01) and the lowest was found in Picholine (6.032 \(\pm\) 0.56). CUPRAC reducing activity was expressed in mg GAE/g (gallic acid equivalent). \begin{table}
\begin{tabular}{c c c c c} \hline  & & \multicolumn{2}{c}{DPPH} \\ \hline \multirow{3}{*}{**Cultivar**} & \multirow{3}{*}{**Date**} & \multicolumn{2}{c}{**IC\({}_{50}\) of**} & \multirow{3}{*}{_IC\({}_{50}\) of Acid_**} & \multirow{3}{*}{_IC\({}_{50}\) of_**} \\  & & _Alkaline_ & & _Hydrolysis_ & \\  & & & _Hydrolysis_ & \\ \hline _Bidni_ & 26 October 2021 & 0.43 \(\pm\) 0.05 & 1.12 \(\pm\) 0.13 & 2.51 \(\pm\) 0.18 \\ _Bidni_ & 2 November 2021 & 0.25 \(\pm\) 0.02 & 0.60 \(\pm\) 0.02 & 1.11 \(\pm\) 0.24 \\ _Bidni_ & 16 November 2021 & 3.78 \(\pm\) 0.47 & 3.77 \(\pm\) 0.65 & 2.10 \(\pm\) 0.26 \\ BDS & 28 September 2021 & 0.20 \(\pm\) 0.04 & 1.31 \(\pm\) 0.15 & 1.51 \(\pm\) 0.27 \\ Carolea & 7 October 2021 & 0.70 \(\pm\) 0.02 & 0.50 \(\pm\) 0.10 & 8.76 \(\pm\) 1.03 \\ Carolea & 22 October 2021 & 0.42 \(\pm\) 0.01 & 0.88 \(\pm\) 0.23 & 7.06 \(\pm\) 2.78 \\ Carolea & 17 November 2021 & 5.00 \(\pm\) 0.72 & 7.79 \(\pm\) 0.81 & 2.34 \(\pm\) 0.26 \\ Cerasuola & 2 November 2021 & 0.85 \(\pm\) 0.02 & 1.26 \(\pm\) 0.14 & 8.69 \(\pm\) 0.96 \\ Coratina & 27 September 2021 & 0.61 \(\pm\) 0.10 & 0.31 \(\pm\) 0.04 & 5.29 \(\pm\) 1.13 \\ Coratina & 25 October 2021 & 0.65 \(\pm\) 0.06 & 0.98 \(\pm\) 0.11 & 3.68 \(\pm\) 0.27 \\ Frantoio & 27 September 2021 & 0.78 \(\pm\) 0.18 & 0.94 \(\pm\) 0.04 & 6.18 \(\pm\) 1.08 \\ Frantoio & 4 October 2021 & 0.70 \(\pm\) 0.10 & 0.66 \(\pm\) 0.13 & 2.03 \(\pm\) 0.26 \\ Frantoio & 19 October 2021 & 0.69 \(\pm\) 0.21 & 0.43 \(\pm\) 0.02 & 1.23 \(\pm\) 0.13 \\ Leccino & 17 October 2021 & 2.10 \(\pm\) 0.26 & 3.06 \(\pm\) 0.18 & 3.14 \(\pm\) 0.10 \\ _Malti_ & 29 September 2021 & 2.75 \(\pm\) 0.31 & 4.67 \(\pm\) 0.45 & 7.25 \(\pm\) 0.88 \\ Mixed 1 & 2 October 2021 & 0.48 \(\pm\) 0.06 & 0.44 \(\pm\) 0.09 & 1.89 \(\pm\) 0.34 \\ Mixed 2 & 30 September 2021 & 0.43 \(\pm\) 0.13 & 2.22 \(\pm\) 0.25 & 1.79 \(\pm\) 0.13 \\ _Bajda 1_ & 4 October 2021 & 0.42 \(\pm\) 0.06 & 0.32 \(\pm\) 0.07 & 1.84 \(\pm\) 1.01 \\ _Bajda 2_ & 4 October 2021 & 0.43 \(\pm\) 0.07 & 0.59 \(\pm\) 0.05 & 2.49 \(\pm\) 0.17 \\ Picholine & 7 October 2021 & 0.37 \(\pm\) 0.03 & 0.52 \(\pm\) 0.21 & 2.67 \(\pm\) 0.25 \\ UDP & 4 October 2021 & 0.16 \(\pm\) 0.03 & 0.81 \(\pm\) 0.40 & 2.24 \(\pm\) 0.12 \\ UDP & 7 October 2021 & 0.81 \(\pm\) 0.02 & 0.35 \(\pm\) 0.01 & 3.79 \(\pm\) 0.42 \\ UDP & 25 October 2021 & 0.31 \(\pm\) 0.05 & 0.34 \(\pm\) 0.05 & 1.86 \(\pm\) 0.65 \\ \hline \end{tabular}
\end{table} 
Table 1: C\({}_{508}\) of olive oil extracts for _DPPH Radical Scavenging_ activity. (BDS—Bella di Spagna and UDP—Uovo di Piccione). As shown in Figure 7 the highest reducing activity in FRAP for alkaline hydrolysis was found in the cultivar of Uovo di piccione (30.60 \(\pm\) 4.91), whilst the lowest reducing activity was found in the Maltese cultivar 'Malti' (4.60 \(\pm\) 1.36). For acidic hydrolysis, the highest reducing activity was found in Picholine (20.93 \(\pm\) 2.12) and the lowest was found in Leccino (5.91 \(\pm\) 0.38). Lastly, for the macerated extracts, the highest reducing activity was found in 'Bajda' (Perla Maltese) (10.74 \(\pm\) 0.87) whilst the lowest concentration was found in 'Bajda' (Perla Maltese) (10.74 \(\pm\) 0.87).