Emerging non-thermal technologies are transforming how fresh produce is preserved post-harvest, and among these, corona discharge plasma (CDP) has recently garnered significant attention for its innovative approach to extending shelf life. A groundbreaking study led by Jun Wang from Northwest A & F University and Zhengshi Chang of Xi’an Jiaotong University presents compelling evidence that CDP treatment can notably enhance the storage stability of lily bulbs (Lilium davidii var. unicolor), a valuable horticultural crop prized both as food and for its medicinal properties. Published in the open-access journal Food Innovation and Advances on January 22, 2026, this research pushes the boundaries of plasma technology by elucidating its multifaceted effects on microbial control, antioxidant activity, and bioactive compound enhancement.
Fresh lily bulbs face substantial challenges during storage due to their inherent high moisture content and vigorous metabolic activity, factors that predispose them to rapid decay characterized by browning and microbial infestation. Traditional preservation techniques such as chemical fumigation, application of edible coatings, and controlled atmosphere storage, although partially effective, are plagued by drawbacks including uneven treatment dispersion, potential chemical residues, and environmental sustainability concerns. The burgeoning quest to develop alternative preservation methods without compromising food safety and quality finds a promising solution in plasma technology, particularly CDP, which offers a chemical-free, eco-friendly approach.
The research team embarked on a meticulous experimental protocol wherein freshly harvested lily bulbs were subjected to corona discharge plasma exposure for multiple durations—specifically 2, 4, 6, 8, and 10 minutes—prior to refrigerated storage at 4°C for a protracted period of 60 days. Throughout storage, an arsenal of analytical methods evaluated the bulbs’ microbial load, enzymatic activity, physical texture, color metrics, cellular membrane integrity, and antioxidant status. These comprehensive evaluations revealed that CDP treatment inflicted a profound inhibitory effect on surface-dwelling microbes, encompassing bacteria, molds, and yeasts—pathogens known to accelerate spoilage and compromise post-harvest quality.
Quantitatively, a six-minute plasma exposure yielded a bacterial inactivation rate exceeding 78% immediately post-treatment, an inhibition that was robustly maintained across the entire storage interval. This enduring microbial suppression starkly contrasted with untreated control samples, which exhibited rapid microbial proliferation leading to overt deterioration. The distinctive advantage of CDP lies not merely in its antimicrobial capability but also in its contribution to preserving the physical quality attributes of lily bulbs. Whereas untreated specimens displayed progressive softening and textural degradation, plasma-treated bulbs, especially those exposed for four minutes, retained structural firmness around 30% higher than controls after two months of storage.
A critical aspect of cellular integrity was assessed through measurements of relative electrical conductivity and malondialdehyde (MDA) levels—parameters widely recognized as hallmarks of membrane disruption and lipid peroxidation. Plasma treatment markedly diminished the escalation of these indicators, suggesting that CDP fortifies cell membranes against oxidative injury and mitigates physiological senescence phenomena. Such protection is pivotal in maintaining cellular homeostasis and prolonging the functional lifespan of storage tissues.
Beyond biophysical assessments, the researchers explored the biochemical pathways influenced by CDP exposure. Intriguingly, the activities of key antioxidant enzymes — superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) — were significantly upregulated post-plasma treatment. These enzymes constitute primary defense mechanisms against reactive oxygen species (ROS), which are known to accumulate during stress and trigger cellular damage. Enhanced enzymatic activity endows plant tissue with increased resilience to oxidative stress, thereby slowing senescence.
Concomitant with enzymatic augmentation was a noted elevation in secondary metabolites, including phenolic compounds and flavonoids, particularly pronounced in bulbs treated for six minutes. These bioactive molecules are central to the plant’s intrinsic defense and antioxidant systems, contributing to both pathogen resistance and health-promoting qualities. Antioxidant capacity assays such as DPPH, ABTS, and FRAP corroborated these biochemical enhancements, underscoring the heightened radical scavenging potential induced by plasma treatment.
Microscopic imaging of lily bulb surfaces post-CDP exposure revealed the formation of sub-micron scale pores, a morphological alteration that likely facilitates improved gas and nutrient exchange. This microstructural modification may also act as a stimulus for metabolic pathways associated with antioxidant synthesis, thereby linking physical surface changes with biochemical responses. This dual action underpins the superiority of CDP as a non-invasive and biostimulatory preservation technology.
The implications of this investigation are profound. CDP represents an emerging preservation paradigm that harnesses physical plasma fields to integrate microbial control, physiological protection, and metabolic stimulation. This approach circumvents the environmental and health concerns tied to chemical preservatives while being compatible with sustainable agricultural practices. Leveraging plasma technology could revolutionize post-harvest management across diverse horticultural products, mitigating food waste and ensuring consistent quality for consumers.
Given the global imperative to optimize food supply chains under escalating population pressures and environmental constraints, the findings disseminated by Wang, Chang, and colleagues resonate emphatically with future food security agendas. Their work establishes a scientific foundation for scaling plasma treatment systems in commercial settings and encourages further exploration into plasma’s mechanistic interactions with biological tissues at molecular and cellular resolutions.
In summary, corona discharge plasma emerges not just as a microbial barrier but also as a multifactorial enhancer of post-harvest quality. By intertwining antimicrobial efficacy, cellular stabilization, and antioxidant fortification, the study delineates a comprehensive preservation strategy that elevates the shelf life and nutritional value of lily bulbs. As research progresses, the seamless integration of plasma technologies could redefine how freshness and safety are maintained in fresh produce industries worldwide.
Subject of Research: Not applicable
Article Title: Shelf life extension of lily (Lilium davidii var. unicolor) bulbs by corona discharge plasma processes
News Publication Date: 22-Jan-2026
References:
DOI: 10.48130/fia-0025-0051
Image Credits: The authors
Keywords
Plant sciences, Biochemistry, Post-harvest preservation, Corona discharge plasma, Antioxidant enzymes, Microbial inhibition, Food technology, Non-thermal preservation, Secondary metabolites, Shelf life extension
