Optimization of Ultrasonication Probe-Assisted Extraction Parameters for Bioactive Compounds from Opuntia macrorhiza Using Taguchi Design and Assessment of Antioxidant Properties

Move over, ordinary fruits—there's a cactus hiding a treasure trove of health-boosting compounds, and scientists just found the perfect way to unlock it. Red prickly pear, or Opuntia macrorhiza, is packed with polyphenols, ascorbic acid, and betalains, but only now are we learning how to extract them efficiently.

Ultrasound probe-assisted extraction (UPAE) is like giving plant cells a sonic shake-up, using high-frequency sound waves to break open cell walls and release their valuable contents. In this study, scientists optimized UPAE parameters—solvent type, liquid-to-solid ratio, extraction time, and pulsation—for both the pulp and peels of Opuntia macrorhiza fruits. Using Taguchi design, they found that aqueous extraction for 12 minutes with a 60 mL/g ratio and 48 pulses/min worked best for pulp, while peels required 20 minutes, same ratio and pulsation. The results were then compared to traditional stirring extraction, and UPAE won hands down, yielding higher amounts of polyphenols (10.27–13.07 mg gallic acid equivalents per gram dry weight) and betalains (974–1099 µg per gram). These fruits show promise as new food and medicinal ingredients, thanks to their antioxidant properties and non-toxic nature.

Key Points

• Ultrasound probe extraction outperforms stirring extraction
• Optimal aqueous conditions: 12–20 min, 60 mL/g, 48 pulses/min
• Polyphenols: 10.27–13.07 mg GAE/g; betalains: 974–1099 µg/g