## 3 Results  
Extraction Efficiency of Amphiphilic and Lipophilic Lipid Components from Apple Juice and By-Products Samples  
The yield of extraction for the TL, TAC and TLC extracts in both the apple juice and apple pomace are shown in Table 1. These data show that the TL extracts of all apple samples (juices and by-products) are mainly composed of TAC, 19.5 mg/100 mL juice and 12.1 mg/100 g pomace, respectively, while much lower amounts of TLCs are present for apple juice, 8.5 mg/100 mL juice, and for apple pomace, 6.2 mg/100 g pomace, as shown in Table 1, as the amounts of TACs in all extracts were statistically significantly higher from the relative TLC amounts (\(p<0.05\)) in both the apple juice and apple pomace. For example,the yield in TACs from apple by-products was found to be thrice more abundant in the TLs than in the yield for their TLC. Interestingly, in this apple variety (Starking), the TL content was found to be higher in the apple juice than in its by-products, different to what was previously observed with the same extraction methodology in other studies for other apple varieties (Jonagold, Dabinett and Aston Bitter [10; 11]), in which the yields for TLs from apple pomace were higher than those from the apple juice. Nevertheless, in all the apple varieties that have been studied so far, including the present study, as aforementioned within the TLs, the TAC contents prevail in comparison to the much lower TLC contents in both juice and apple pomace, which further suggests that Starking apple pomace is also a good sustainable source of TAC bioactives. Total Phenolic and Carotenoid Contents and Antioxidant Activity of TAC, TLC and TL Extracts from Apple Juice and Its By-Products  
3.2.1. Total Phenolic and Carotenoid Contents  
The total phenolic content (TPC) of all TAC, TLC and TL extracts of both apple juice and by-products samples is shown in Table 2, expressed in mg Gallic acid equivalents per g of dry weight extract (GAE/g DW). TLs of apple juice contained similar TPC with that of the apple pomace TLs, 19.1 mg/100 mL juice and 23.8 mg/100 g pomace correspondingly, and both were found to be lower than previously reported data for apple juice and by-products [12; 13; 14; 15; 16], but it should be mentioned that different extraction methodology was applied in the other studies which focused mainly on obtaining phenolics. In the present study, the TLs were derived from an extraction procedure based on chloroform and methanol, which is a less polar system of solvents than the solvents that were used in the previously reported studies. The specific methodology was chosen to co-extract in the same TL extract the total amphiphilic content, meaning both phenolic and polar lipid bioactives, and not only the phenolics from these apple sources, which was the case in the previously reported data. In a second step, with the counter current separation technique applied in this study we managed to further separate the more polar amphiphilic content (including phenolics and polar lipids) from the TLCs of all TL extracts, by using a hydroalcoholic system versus a non-polar solvent like petroleum ether [7]. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Sample/Extract** & \multicolumn{2}{c}{**TACs**} & \multicolumn{2}{c}{**TLCs**} & \multicolumn{2}{c}{**TLs**} \\ \hline  & min–Max value & Median value & min–Max value & Median value & min–Max value & Median value \\ \hline Apple juice (mg/100 mL juice) & 18.6–55.0 & 19.5 & 6.25–11.0 & 8.5 & 6.3–55.0 & 14.8 \\ \hline Apple by-products (mg/100 g pomace) & 11.1–18.7 & 12.1 & 3.5–6.9 & 6.2 & 3.5–18.7 & 9.0 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Yield of extraction for the total amphiphilic compounds (TACs), total lipophilic compounds (TLCs) and total lipid compounds (TLs), expressed as mg/100 mL sample for juices and as mg/100 g sample for by-products.