## 5 Methods of Extraction of Bioactive Substances from Grape and Winery By-Products
### Limitations of Extraction and the Use of Bioactive Components  
The entire process, from extraction to the use of bioactive molecules of grape and winery by-products, has been well improved. However, it has naturally presented challenges and limitations as summarized in Table 2, most of which are related to the extraction of bioactive compounds and their exploitation on an industrial scale [73]. Examples from studies indicate that the lack of universally applied processes and methods, the high demands and high costs of equipment, the environmental impact of the use of certain techniques, and consumers' suspicion of products containing such bioactive substances are a sample of these limitations [73]. Some proposals to address a part of these limitations include using more advanced analytical techniques to standardize the bioactive constituents of grape by-products, as well as finding and using more sustainable extraction techniques. The utilization of various enzymes or the use of water as a solvent make extraction techniques safer, more attractive for use in cosmetic products, and more trustworthy for consumers [74].  
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Extraction Method** & **Advantages** & & **Disadvantages** & **References** \\ \hline Solid-Liquid & \(\bullet\) & Simple and widely used & \(\bullet\) & Particle size, temperature, and solvent type & \\ Extraction (SLE) & \(\bullet\) & Scalable to medium or large processes & & affect extraction & [48, 51, 69] \\  & & Compared to maceration, Soxhlet improves analyte solubility and efficiency & \(\bullet\) & Time-consuming & \\ \hline Ultrasound-Assisted Extraction (UAE) & \(\bullet\) & Fast and efficient & \(\bullet\) & For effectiveness, you must create a stable & \\ Extraction (UAE) & \(\bullet\) & Environmentally friendly with low solvent and & \(\bullet\) & temperature and ultrasound intensity & [52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64] \\ \hline Microwave-Assisted Extraction (MAE) & \(\bullet\) & High efficiency and operational viability & \(\bullet\) & Restriction to polar solvent application & \\  & & Green method & \(\bullet\) & Optimization needed to avoid compound & [56, 57, 58, 59, 60] \\  & & Effective for polyphenol extraction & & degradation & \\ \hline \multirow{3}{*}{Supercritical Fluid Ex-Traction (SFE)} & \(\bullet\) & Environmentally friendly with no toxic solvent needs & \(\bullet\) & Increased control and equipment requirements & \\  & & High selectivity for substances & \(\bullet\) & Restrictions on the use of specific solvents & [61, 62, 63, 64, 65, 66] \\  & & Cost-effective & \(\bullet\) & Sensitivity to parameter settings & \\  & & Fast and efficient & & \\ \hline Enzyme-Assisted Extraction (EAE) & \(\bullet\) & High yields by breaking down complex structures & \(\bullet\) & Expensive method & \\  & & Operates under mild conditions & \(\bullet\) & Pretreatment may not significantly improve & [67, 68, 69, 70, 71] \\  & & Reduced solvent and time requirements & & some compound extractions & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Advantages and disadvantages of extraction methods.