AbstractBACKGROUNDTo manage industrial waste in accordance with the circular bioeconomy concept it is sometimes necessary to handle grape seeds, an abundant by‐product of the wine‐making process. This study presents a process based on ultrasound technology for the extraction of grape‐seed proteins, due to their nutritional and techno‐functional properties. The protein content of extracts obtained under silent and lab‐scale conditions was compared with that obtained under semi‐industrial ultrasound conditions, and the chemical composition (carbohydrates, total phenols, and lipids) and the elemental profiles of the final, up‐scaled downstream extracts were characterized.RESULTSThis work found that the maximum amount of protein in the final product was 378.31 g.kg−1 of the extract. Chemical characterization revealed that each 1 kg of extract had an average content of 326.19 g gallic acid equivalent as total phenols, 162.57 g glucose equivalent as carbohydrates, and 382.76 g of lipophilic compounds. Furthermore, when the extract was checked for hazardous elements, none were found in levels that could be considered a risk for human health.CONCLUSIONThe proposed semi‐industrial strategy has the potential to contribute greatly to the valorization of grape seeds through the preparation of a protein‐rich extract that can be used as an alternative to synthetic wine stabilizers and for the development of novel food and nutraceutical products. © 2024 Society of Chemical Industry.