Ultrasound‐assisted extraction and purification of bromelain from pineapple ( <scp> <i>Ananas comosu</i> </scp> <i>s</i> ) stem waste using ethanol precipitation and resin adsorption

Abstract Bromelain, a proteolytic enzyme from the Bromeliaceae family, is valued for its industrial applications and high demand, particularly in pharmaceuticals. This study evaluated ultrasound‐assisted extraction and purification of bromelain from pineapple ( Ananas comosus (L.) Merril) stem waste for industrial‐scale potential, involving raw material characterization, ultrasound extraction with water, ethanol precipitation, and resin adsorption. The stem showed the highest enzymatic activity (2.255 ± 0.089 U · mL −1 without ultrasound, up to 3.622 U · mL −1 with ultrasound at optimal conditions: 1:2 tissue‐to‐water ratio, 25°C, 22% power), making it the primary raw material. Ultrasound enhanced activity by ~60% and reduced processing time to 10 min compared to conventional methods. Two‐stage ethanol precipitation (30% and 70% v/v) achieved 82% recovery, increasing specific activity from 0.852 to 1.143 U · mg −1 . Batch adsorption with Amberlite IRA 410 resin yielded a purification factor of 10.73 and specific activity of 9.143 U · mg −1 by removing non‐target proteins, though it did not selectively bind bromelain. Overall, this process confirms viability for industrial implementation in valorizing pineapple waste.