## 3 Results
### Total Phenolic Content and Antioxidant Capacity  
Table 9 shows the mean values of TPC and the antioxidant capacity of the CS extracts. Natural _Arabica_ CS had a significantly higher TPC content. Overall, samples subjected to natural post-harvest treatment had higher TPCs, similar to those reported in a previous study [21], with _Arabica_ CSs generally characterised by higher TPCs than those of _Canephora_. This trend contrasts that reported by other authors [59] but followed the tendency observed with respect to the content of phenolic compounds. Significantly higher DPPH and ORAC values (average of 50 umol TE/g and 348 umol TE/g, respectively) were detected in natural _Arabica_ CS, independent of the roasting process. However, it was difficult to compare our results with those reported in the literature because of different solvent extraction procedures and type of expression of results, often attributed to the extract rather than the sample. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & **Species** & **Treatment** & **Roasting** & **S \(\times\) T** & **S \(\times\) R** & **T \(\times\) R** & **S \(\times\) T \(\times\) R** \\  & **(S)** & **(T)** & **(R)** & **(R)** & **(S)** \(\times\) T & **S \(\times\) R** & **S \(\times\) T \(\times\) R** \\ \hline
5 CQA & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 \\
4 CQA & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 \\ FQA1 & 0.104 & 0.000 & 0.000 & 0.185 & 0.000 & 0.000 & 0.013 \\ FQA2 & 0.000 & 0.001 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 \\ Di-CQA1 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 \\ Di-CQA2 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 & 0.000 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Values of significance determined using factorial ANOVA performed on values of production factors and their interactions for the content of phenolic compounds detected in CS samples. With respect to the roasting process, the TPC, DPPH, and ORAC assays deferred. In most cases, we observed an increase in TPC values with an increase in the roasting degree (above all for washed _Arabica_), whereas DPPH and ORAC values were characterised by more variable trends, such as that ORAC increased or decreased alternatively with the roasting degree. The different reaction mechanisms and/or affinities for specific antioxidants in the adopted assays can be linked to the balance between the degradation rate of phenolic compounds and the generation of the Maillard reaction products that characterise the roasting process. It is well known that during roasting, the majority of phenolics present in coffee beans are partially destroyed and/or bound to high-molecular-weight polymers, mainly melanoidins, which are responsible for the strong antioxidant properties and metal-chelating ability of coffee brews [60], in addition to diterpenes that are present in CS and possess relevant antioxidant activities [13]. Nevertheless, [PERSON] et al. [61] reported a progressive reduction in the antioxidant capacity of coffee brews with the degree of roasting, with the highest capacity in medium-roasted coffee. As reported by [PERSON] and [PERSON] [60], high-molecular-weight polymerised melanoidins contribute to the coffee brew antioxidant capacity less than low-molecular-weight Maillard reaction products. Factorial ANOVA (Table 10) highlighted that the treatment was significant for all parameters evaluated, with the highest values for natural products. Coffee species was significant only for TPC and RSA, whereas roasting was significant only for TPC, with the highest values for the dark-roasted product. All interactions showed significant effects on TPC, whereas for the antioxidant parameters, only some interactions showed significant effects.