Subcritical water extraction (SWE) is a highly efficient and eco-friendly method for extracting compounds. In this study, SWE was used to extract resveratrol (RES) from grape seeds, which are by-products of wine production. Researchers tested how different process factors affect the amount of RES extracted, using single-factor experiments. They then optimized the process using a method called response surface methodology (RSM).
Among all the variables, extraction temperature had the biggest effect on how much resveratrol was recovered. The optimal conditions were: pressure at 1.02 MPa, temperature at 152.32 °C, extraction time of 24.89 minutes, and a solid-to-liquid ratio of 1:15 g/mL. Under these settings, the predicted RES yield was 6.90 micrograms per gram of grape seed, with a recovery rate of up to 91.98%.
Compared to older methods, this approach produced less pollution and took less time. These results suggest that SWE is a sustainable and valuable way to extract resveratrol from grape seed waste, potentially adding economic value to this agricultural by-product.
doi:10.3390/app7040321