Encapsulation of Rosemary Extracts using High Voltage Electrical Discharge in Calcium Alginate/Zein/Hydroxypropyl Methylcellulose Microparticles

What if a lightning bolt could help preserve the health benefits of rosemary? High-voltage electrical discharge is proving to be a green way to extract and protect these bioactive compounds.

The demand for functional foods is rising, pushing industries toward greener methods. Researchers have turned to high-voltage electrical discharge—a kind of controlled lightning—to extract bioactive polyphenols from rosemary. This green extraction method is paired with microencapsulation, a protective shell that could deliver these compounds safely into future food products.

Using ionic gelation, the team created four types of microparticles from biopolymers: alginate, zein, and hydroxypropyl methylcellulose (HPMC). The dry particles measured between 651 and 1087 micrometers, appearing spherical with a granular surface. Notably, the alginate/zein microparticles achieved a loading capacity of up to 11.31 mg GAE/g, indicating high encapsulation efficiency.

The real breakthrough came during digestion simulation. The microparticles shielded the polyphenols from pH changes, and the addition of zein and HPMC to alginate prolonged their release, ensuring better absorption in the intestine. This shows that the initial biopolymer composition is key to controlling release, opening the door for tailored functional foods.

Key Points

• High-voltage discharge extracts rosemary polyphenols greenly.
• Alginate/zein microparticles load up to 11.31 mg GAE/g.
• Zein and HPMC prolong release for intestinal delivery.