Revealing the potential of atmospheric cold plasma to deliver safer food

Soybean growing in hydroponic after ACP treatment in the PHEED Lab, Texas A&M University

Atmospheric Cold Plasma (ACP) is a novel, non-thermal technology that ionises gases to generate reactive gas species at atmospheric pressure and temperature. Unlike traditional plasma systems, which require high temperatures, ACP functions under mild conditions, making it ideal for applications in food science and agriculture.

It is generated by applying a high voltage between electrodes in a gaseous medium, such as air or modified air, resulting in a plasma matrix rich in reactive oxygen species (ROS) and reactive nitrogen species (RNS). These reactive species have high antimicrobial properties and are capable of inducing structural changes, improving food safety and functionality without compromising nutritional value.¹

Powerful yet gentle

It has several other advantages over current food safety methods, such as adaptability, short treatment times and low energy consumption. The active gas species also reverts to its original state after application, making the process ecologically safe. This technology is suited to sensitive raw and fresh food products as it does not impact its nutritional and sensory characteristics.² ACP’s adaptability, energy efficiency and environmentally friendly credentials make it a promising alternative to traditional chemical treatments in food processing.

There are several plasma-generating techniques, including dielectric barrier discharge (DBD), gliding arc discharge (GAD), plasma jets, corona discharge, and radio frequency (RF) plasma, each with unique advantages based on energy requirements and application specificity.³ Among these, DBD plasma stands out in my research due to its uniform plasma generation, controlled treatment conditions and adaptability in modifying food components while maintaining product quality.⁴

Research applications

In my research at the Post-Harvest Engineering and Education (PHEED) Lab at Texas A&M University, I explored the potential of ACP in enhancing cereal and grain quality, functionality and safety. Using the DBD method for ACP generation, my team has observed promising results in improving seed germination and reducing the uptake of toxic heavy metals.

As a doctoral researcher under the guidance of Dr Janie Moore, I have studied the effects of ACP-treated water on several grain and cereal crops, including soybeans, wheat and cotton. My findings indicate significant enhancements in seed germination rates, seed sizes and plant development metrics, demonstrating ACP’s potential as a non-chemical, environmentally sustainable solution for agricultural enhancement. For example, when soybean seeds were germinated using ACP-treated water, germination rates increased significantly compared to untreated seeds, with seed size increasing by 26.7 percent at a higher voltage exposure of 70kV for seven minutes. Even at lower treatment levels –50kV for three to five minutes – germination rates reached as high as 93.3 percent, highlighting that even short exposure to ACP can positively impact seed viability.

Moreover, nearly 81.5 percent of ACP-treated seeds exhibited increased radicle (root) growth, a crucial indicator of seedling vitality. Similar benefits were observed with wheat seeds, where ACP-treated water not only accelerated germination but also facilitated root and shoot growth, improved water absorption, and strengthened early-stage seedling development. To examine the long-term impact of ACP-treated water on plant growth under regulated nutrient conditions, I used a controlled hydroponic system. The results were remarkable: soybean plants cultivated in ACP-treated water exhibited enhanced root structure and biomass accumulation, demonstrating that ACP can influence plant metabolic activity and nutrient absorption efficiency.

Heavy metals

A key focus of my research is also investigating how ACP can reduce heavy metal uptake and accumulation in plants, a critical concern for food safety and human health. To explore this, I introduced lead (Pb), a toxic heavy metal, into the hydroponic system while growing soybeans. Heavy metal accumulation in edible crops poses significant risks, as consumption can have severe health consequences. Previous studies have suggested that certain nanoparticles, such as zinc oxide (ZnO), can mitigate heavy metal absorption due to their molecular interactions with metal ions.

Building on this knowledge, I integrated ACP-treated water with zinc oxide nanoparticles in my hydroponic system and observed a substantial decrease in lead absorption by the soybean plants. This finding suggests that ACP, when combined with nanotechnology, holds immense potential as a sustainable approach to addressing heavy metal contamination in crops, ensuring safer food production while reducing environmental toxicity. These findings were published in ‘Effect of High-Voltage Atmospheric Cold Plasma treatment on germination and heavy metal uptake by soybeans (Glycine max)’.⁵

I am currently conducting a similar study on wheat, investigating the effect of ACP-treated water on reducing cadmium (Cd) uptake in a hydroponic system. Cadmium is a highly toxic heavy metal frequently found in wheat crops, posing a serious threat to food quality and human health due to its bioaccumulation in grains.

Chronic exposure to cadmium through food consumption has been linked to kidney dysfunction, bone abnormalities and other health issues, making its reduction a priority for global food security. Seeking to address this issue, I am growing wheat in a controlled hydroponic environment, introducing cadmium to replicate real-world contamination scenarios, and evaluating the effectiveness of ACP treatment as a potential solution.

Based on my earlier findings with soybeans, I am optimistic that ACP can significantly mitigate cadmium absorption, ultimately enhancing the safety and nutritional quality of wheat. If successful, this research could pave the way for scalable, non-chemical strategies to safeguard staple crops from toxic metals, ensuring healthier and safer food for consumers worldwide.

The implications of my research extend beyond laboratory conditions and hold significant promise for global agriculture and food security. Under the expert mentorship of Dr Janie Moore, I am continuously exploring new applications of ACP in food science. In addition to my work on heavy metal reduction, I have also investigated innovative food processing techniques that enhance the quality and safety of cereal-based products.

In a recent publication,⁶ my colleagues and I demonstrated that ACP can effectively replace traditional chemical treatments such as chlorination in wheat flour processing. Our study confirmed that ACP-treated flour achieves comparable functionality to chemically treated flour, offering a cleaner, chemical-free alternative for enhancing baking performance. This research not only advances scientific understanding of ACP’s impact on flour quality but also aligns with industry trends towards cleaner-label food processing.

Summary

ACP represents a transformative technology with numerous benefits across the food supply chain. It enhances agricultural quality and yield, reduces reliance on chemical treatments and improves food safety by minimising harmful chemical residues. My work investigating the potential of ACP is contributing to the development of safer, more efficient and sustainable agricultural practices. Through continued research, I aim to expand scientific knowledge and provide actionable insights that can influence industry standards and regulatory frameworks in food processing and safety. As global food systems increasingly prioritise sustainability and chemical-free processing, this knowledge serves as a foundation for the broader application of plasma technology as a viable and scalable solution for the future of food production.

References

1. Zhang K, Zhao M, Sun DW, Tiwari BK. (2023). Correlation of plasma generated long-lived reactive species in aqueous and gas phases with different feeding gases. Plasma Sources Science and Technology, 32(4), 045015.
2. Harikrishna S, Anil PP, Shams R, Dash KK. (2023). Cold plasma as an emerging nonthermal technology for food processing: A comprehensive review. Journal of Agriculture and Food Research, 14, 100747.
3. Farooq S, Dar AH, Dash KK, et al. (2023). Cold plasma treatment advancements in food processing and impact on the physiochemical characteristics of food products. Food Science and Biotechnology, 32(5), 621-638.
4. Zhou B, Zhao H, Yang X, Cheng JH. (2024). Versatile dielectric barrier discharge cold plasma for safety and quality control in fruits and vegetables products: Principles, configurations and applications. Food Research International, 115117.
5. Mahanta S, Habib MR, Moore JM. (2022). Effect of high-voltage atmospheric cold plasma treatment on germination and heavy metal uptake by soybeans (Glycine max). International Journal of Molecular Sciences, 23(3), 1611.
6. Mahanta S, Bock J, Mense A, et al. (2024). Atmospheric cold plasma as an alternative to chlorination in soft wheat flour to prepare high-ratio cakes. Foods, 13(15), 2366.

About the author  

Shikhadri Mahanta is a doctoral candidate in Biological and Agricultural Engineering at Texas A&M University. Her research emphasises the novel application of Atmospheric Cold Plasma (ACP) technology to enhance the quality and safety of grain production, particularly wheat. Through her studies on improving wheat seed germination, optimising plant growth, and reducing toxic heavy metal uptake, Shikhadri significantly contributes to advancing safer, sustainable and chemical-free food production systems with promising implications for global food security.