Display omitted •High bioactive components reveals valorisation potential of the Cabernet pomace.•Yield of polyphenols has a direct correlation on the extraction conditions.•Ultrasound as a standalone is insufficient in enhancing yield of polyphenols.•Ultrasound with shaking involves low energy, accelerated and intensified polyphenols.•Results reveal sustainable polyphenols extraction from grape pomace. The compositional analysis of Cabernet grape pomace showing higher polyphenols, dietary fiber and proteins reveals its potential to be valorised as a possible functional food. For assessment of potential intensification of polyphenols extraction yields, different extraction techniques under various operating conditions were experimented upon and further optimised. Ultrasonication as a standalone technique resulted in lower polyphenols yields. Whereas ultrasonication when combined with conventional shaking extractions and carried out under conditions of 45°C and 40:1 aqueous ethanolic solvent demonstrated higher yields of 2079.33mg/100g of dry grape pomace. The predictive yield as per statistical analysis was 2081.66mg/100g revealing a close agreement between experimental and theoretical values. Kinetic studies further showed that ultrasonication with subsequent shaking resulted in relatively lower activation energy causing greater and faster diffusion of the polyphenols into the solvent matrix. The outcome of this study reveals that grape pomace has significant antioxidant components like polyphenols; but maximum extraction yields involving lesser energy and time requires the involvement of a shorter ultrasonication in combination with conventional shaking extractions under optimized process control.