Green Extraction of Antioxidant Fractions from Humulus lupulus Varieties and Microparticle Production via Spray-Drying

What if the secret to a healthier snack lies in beer's bitter flower? Scientists have turned hop extracts into tiny, antioxidant-packed microparticles using nothing but water and ultrasound.

Hops are famous for flavoring beer, but their antioxidant power is a hidden gem. Researchers used two green extraction methods—ultrasound-assisted and pressurized hot water—to pull bioactive compounds from Nugget and Perle hop varieties. The resulting liquid fractions were rich in phenolics, proteins, and oligosaccharides, showing strong free-radical scavenging activity in lab tests.

The ultrasound extracts proved best for drying. Spray-drying at 120–130°C achieved a remarkable 77% yield, turning the liquid into stable microparticles with mannitol as a carrier. These particles ranged from tiny 100-micrometer spheres (Nugget) to larger 250–750-micrometer beads (Perle), with viscosity suitable for various applications.

This sustainable approach avoids toxic solvents entirely, making it safe for food and non-food uses. The study shows that green chemistry can deliver both performance and environmental friendliness—one bitter flower at a time.

Key Points

• Green extraction: ultrasound and hot water, no toxic solvents.
• Spray-drying achieved 77% yield at 120–130°C.
• Microparticles with mannitol: size 100–750 μm, viscosity 30–70 mPa·s.