Green Extraction Methods Applied to the Brown Macroalga Saccharina latissima: Assessing Yield, Total Phenolics, Phlorotannins and Antioxidant Capacity

What if the secret to sustainable antioxidants lies in an overlooked seaweed? A new study unlocks the potential of Saccharina latissima using green extraction methods that boost yields by up to 65.76%.

The brown seaweed Saccharina latissima is abundant yet underutilized, but it's packed with bioactive compounds like phlorotannins—a type of polyphenol with antioxidant power. Researchers are now turning to eco-friendly extraction methods to tap into this resource without harming the planet.

Two green techniques took center stage: pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE), both optimized using a Box–Behnken design. These methods use GRAS solvents (generally recognized as safe) and consume less energy, making them a win for sustainability. The team measured not just yield, but also the quality of the extracts—total phenolics, phlorotannin levels, and antioxidant capacity via DPPH and ABTS assays.

The results were striking. Optimized MAE (at 80°C with 2% ethanol in water) and PLE2 (just water at 80°C) increased yields by 65.76% and 37.36% compared to conventional extraction. PLE2 also boosted total phenolic content by 61.88% and ABTS antioxidant activity by 80.39%, while MAE improved these by 53.90% and 36.42%, respectively. Statistical modeling confirmed the accuracy of the predictions (R² > 0.86).

These eco-efficient methods offer a practical path to valorize brown algae, turning a common seaweed into a valuable source of natural antioxidants for industry. It's a small step for a lab, but a giant leap for sustainable chemistry.

Key Points

• Green extraction (PLE, MAE) boosts yields by up to 65.76%
• PLE2 increases phenolic content and antioxidant activity by ~80%
• Eco-friendly methods valorize underutilized brown seaweed