By inhibiting microbial growth, strengthening antioxidant defense systems, and stimulating beneficial secondary metabolites, the method effectively slows post-harvest deterioration. The findings suggest that plasma-based preservation could provide a safe, chemical-free solution for reducing food waste and improving storage stability in high-value horticultural crops.
Fresh lilies are widely valued as edible vegetables and medicinal ingredients, especially in regions such as Lanzhou, China. However, their high moisture content and active metabolism make them vulnerable to browning, microbial infection, and rapid quality loss during storage. Conventional preservation methods—including chemical fumigation, coatings, and controlled atmosphere storage—can delay spoilage but often suffer from limitations such as uneven treatment, chemical residues, or environmental concerns. These challenges have prompted researchers to explore alternative technologies that can extend shelf life while maintaining food safety and product quality.
A study (DOI: 10.48130/fia-0025-0051) published in Food Innovation and Advances on 22 January 2026 by the team of Jun Wang (Northwest A & F University) and Zhengshi Chang (Xi'an Jiaotong University), reports that optimal plasma pretreatment significantly reduces microbial contamination and enhances antioxidant capacity, ultimately improving storage quality and prolonging the shelf life of lily bulbs.
To evaluate the effectiveness of CDP treatment, researchers collected freshly harvested lily bulbs and exposed them to corona discharge plasma for varying durations—2, 4, 6, 8, and 10 minutes—before storing them at 4 °C for 60 days. Multiple indicators of quality were measured during storage, including color change, microbial counts, tissue firmness, cellular integrity, enzyme activity, and antioxidant properties. Microbial analysis revealed that plasma treatment substantially suppressed bacterial, mold, and yeast populations on lily surfaces. For example, samples treated for six minutes showed a bacterial sterilization rate of over 78% at the beginning of storage and maintained significantly lower microbial loads even after 60 days. The treatment effectively slowed spoilage and prevented the rapid decay observed in untreated samples. Physical quality assessments further confirmed the protective effects of plasma exposure. While untreated bulbs experienced noticeable softening during storage, CDP-treated samples retained greater firmness, with the four-minute treatment maintaining about 30% higher hardness after 60 days. Measurements of relative conductivity and malondialdehyde (MDA)—indicators of membrane damage and lipid oxidation—also showed reduced cellular deterioration in treated bulbs. These findings suggest that plasma treatment helps preserve cell membrane integrity and slows physiological aging during storage. The researchers also investigated biochemical responses to plasma treatment. They observed significant increases in antioxidant enzyme activities, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). These enzymes help neutralize reactive oxygen species and protect plant tissues from oxidative stress. Meanwhile, the levels of beneficial secondary metabolites such as phenolic compounds and flavonoids were markedly elevated, particularly in bulbs treated for six minutes. Enhanced antioxidant capacity was confirmed by higher DPPH, ABTS, and FRAP values during storage. Microscopic observations revealed that plasma exposure created micro-scale pores on the lily surface, improving mass transfer and stimulating metabolic responses that promote antioxidant synthesis.
Overall, the research demonstrates that corona discharge plasma is a promising non-thermal preservation technology capable of improving the post-harvest stability of lily bulbs. By simultaneously suppressing microbial growth, strengthening antioxidant defenses, and promoting bioactive compounds, CDP treatment offers a safe and environmentally friendly alternative to chemical preservation methods. The technology may provide valuable new opportunities for extending the shelf life of fresh produce, reducing post-harvest losses, and enhancing the sustainability of horticultural supply chains.
