Microgreens, tiny seedlings of vegetables like radish, broccoli and kale, are packed with vitamins, minerals and antioxidants, but they spoil quickly. Now, a new Penn State study shows that hot air drying, a simple and inexpensive technique, can preserve much of their nutrition.
Researchers tested how drying radish microgreens at different oven temperatures affected key nutrients. They found that antioxidants were largely stable, with up to 100% retained at the highest temperature tested. A compound in radishes linked to potential anti-cancer effects also held steady at lower drying temperatures and was still about 78% preserved even under high heat. B vitamins fared well overall, while vitamin C was the most sensitive, retaining only about 37% after drying.
The team also simulated digestion to measure how well the nutrients could be absorbed once eaten. Many vitamins and antioxidants remained available for absorption, though some compounds, including certain plant pigments, broke down during the process.
“Microgreens increasingly are popular due to their high concentrations of health-promoting compounds, but their benefits have been limited because they’re highly perishable,” said Joshua Lambert, PhD, professor of food science at Penn State. “So, there’s a clear need for preservation methods that keep nutrients intact.”
The findings, which were published in the Journal of Food Science, suggest that hot air drying could help reduce food waste while making nutrient-dense microgreens more widely available in shelf-stable forms. While some losses occur, particularly for vitamin C, many health-promoting compounds remain intact, offering a low-tech alternative to costly freeze-drying.
This research was supported by the U.S. Department of Agriculture’s National Institute of Food and Agriculture and Open Philanthropy through the Food Resilience in the Face of Catastrophic Global Events grant.