## 4 Potential of Bioactive Compounds Obtained from By-Products of the Wine Industry
### Health and Cosmetics
Research in epidemiology suggests that the polyphenols present in dietary sources, such as wine, have a considerable impact on human health. PVPP  
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**Compounds** & **By-Product** & \begin{tabular}{c} **Extraction Methods and** \\ **Detection Method** \\ \end{tabular}  & **Concentrations** & **Function** & **References** \\ \hline \multirow{3}{*}{Tartaric acid} & \multirow{3}{*}{Wine lees} & Recovery of tartaric acid using cation exchange resin under mild conditions and ambient temperature. & \begin{tabular}{c} Tartaric acid content 575.8 mg.g\({}^{-1}\) \\ dry wine lees. \\ Tartaric acid recovery 99.8\% at ambient temperature. \\ \end{tabular}  & \begin{tabular}{c} Exfoliating, \\ depigmenting, and \\ 40 \({}^{\circ}\)C for 24 h. \\ \end{tabular}  & [142] \\ \hline \multirow{3}{*}{Oleic acid} & \multirow{3}{*}{Grape seed oil} & Oleic acid extraction using methanol. Approximately 1 mL of methanol addition in 0.5 mL of GSO and 0.5 mL of GSO and 1 mL of methanol addition at 10,000 rpm 0.5 mL of GSO and 10,000 rpm 10 min. The supernatant was collected for analysis. & The oleic acid accounts for 6.52-14.51\% of the total fatty acid, depending on the variety of grape. & Anti-aging and \\  & & & & \\ \hline \multirow{3}{*}{Linoleic acid} & \multirow{3}{*}{Grape seed oil} & Linoleic acid extraction using 1 mL of methanol addition in 0.5 mL of GSO and 0.5 mL of GSO and 10,000 rpm 10 min. The supernatant was collected for analysis. & The linoleic acid accounts for 70.90–77.38\% of the total fatty acid, depending on the variety of grape. & Anti-aging & [27] \\ \hline \multirow{3}{*}{Linoleic acid} & \multirow{3}{*}{Grape leaves} & Linoleic acid extraction with a mixture of methanol in sulfuric acid (97.52.5, \(\psi\)/\(\psi\)), incubation at 70 \({}^{\circ}\)C for 1 h. The extracts were recovered in a organic phase after adding a mixture of petroleum ether: ultrapure water (32, \(\psi\)/\(\psi\)). Analysis by gas chromatography. & & \\ \hline \multirow{3}{*}{Vitamin E} & \multirow{3}{*}{Grape seed} & Vitamin E extraction with conventional (Söschilet and mechanical press extraction) and non-conventional (pressurized liquid extraction (PLE) with hexane) methods. & A Vitamin E content of 5.67 mg.100 g\({}^{-1}\) was obtained by PLE for grape seed. & Anti-aging & [142] \\  & & & & \\ \hline \multirow{3}{*}{Ferulic acid} & \multirow{3}{*}{Grape skin} & Ferulic acid extraction with 20 mL of 80\% aqueous methanol and 0.1\% HCl for 1 h with shaking at room temperature. Fliltration and determination by HPLC. & \ \begin{tabular}{c} Ferulic acid concentration \\ 4.2 \(\pm\) 0.15 mg.kg\({}^{-1}\) of dry matter in the grape skin. \\ \end{tabular}  & Sunscreen & [144] \\ \hline \multirow{3}{*}{ProanthocyanidinsGrape pomace} & \multirow{3}{*}{ \begin{tabular}{c} The proanthocyanidins (PAC) were extracted with and without the microwave-assisted extraction (MAE) method. The optimized MAE condition was 94\% ethanol, 170 \({}^{\circ}\)C temperature, and a duration of 55 min. \\ \end{tabular}  } & Under conventional conditions (94\% EtOH; 25 \({}^{\circ}\)C; 55 min), the (PAC) measured & \\  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-  
(polyvinylpolypyrrolidone) a type of water-insoluble polymer known as'synthetic', and is utilized for adsorbing phenolic compounds from beverages. Additionally, it is also employed in the treatment of white wine (legal limit: 80 g.hL\({}^{-1}\)) in the Douro region of Portugal to prevent phenolic oxidation and polymerization. The stability of wine is enhanced by this polymer, which adsorbs phenolic compounds, including those that cause browning reactions and bittermess [150]. This mixture, known as PVPP-white wine extract, is obtained through selective adsorption and contains a high concentration of phenolic compounds, making up roughly 80% of its dry mass. Among these compounds, phenolic acids, such as cafatric acid, and proanthocyanidins, such as catechin oligomers, are the most dominant [150; 151; 152].