Valorization of red beet peel through green extraction and carrier-driven microencapsulation for improved betalain stability

What if the secret to vibrant, natural food color was hiding in the peels you throw away? Red beet peel, often discarded, holds a treasure trove of pigments that science can now stabilize for months.

The global push for sustainability is turning food waste into a goldmine. Red beet peel, a humble by-product, is packed with betalains—natural pigments with potent antioxidant power. But these pigments are fragile. This study set out to change that, using eco-friendly extraction methods and clever encapsulation.

Researchers compared three green techniques: ultrasound, high pressure, and pulsed electric fields. Sonication emerged as the clear winner, yielding the highest levels of total betalains (16.92 mg/g DM), phenolics, flavonoids, and antioxidant activity. This gentle, energy-efficient method unlocked the peel's full potential.

To protect these precious pigments, the team used soy protein isolate and maltodextrin as carriers. Both proved effective, dramatically slowing pigment degradation over 120 days. The encapsulated extracts boasted a predicted shelf-life of 7–12 months, far surpassing the 5 months of non-encapsulated extracts.

This research shows that upcycling agricultural waste isn't just good for the planet—it's a smart business move. By combining green extraction with encapsulation, we can create stable, natural colorants for functional foods, reducing our reliance on synthetic dyes and giving a second life to discarded peels.

Key Points

• Sonication extracts the most betalains from red beet peel.
• Encapsulation with SPI and MD boosts betalain shelf-life to 12 months.
• Upcycled beet peel offers a sustainable source of natural colorants.