Electron Beam and X-ray Technologies in Agriculture and Food Processing: A Viable Alternative to Cobalt-60

Abstract

Ionizing radiation technologies play a vital role in agriculture and food processing, contributing to food safety, shelf-life extension, and facilitating international trade of food commodities. Traditionally, ⁶⁰Co-based gamma irradiation has been used largely for this purpose. However, concerns over the safety of radioactive sources, limited production capacity for ⁶⁰Co, cost of the radioisotope, and national security concerns have prompted a shift toward safer and sustainable alternatives. Machine source-based electron beam (eBeam) and x-ray technologies have emerged as viable alternatives to ⁶⁰Co. These technologies are currently being used in pre-harvest agricultural activities and post-harvest practices such as phytosanitary treatment and food pasteurization. Compared to ⁶⁰Co, eBeam and x-ray technologies offer better economics, greater throughput, and improved dose control without any concerns of radioactive materials or security concerns. Recent advances in the underlying technologies, equipment design, and energy efficiencies have significantly increased the adoption of eBeam and x-ray technologies on a commercial scale worldwide. There are still lingering challenges, such as the initial high cost of investment; unfamiliarity of the core technology among investors, food industry and government decision makers; and regulatory concerns for revalidation. This review paper explores the current global state of science and technology as it relates to ionizing technologies in agriculture and the food industry. The key hurdles in the adoption of eBeam technology have been identified along with practical solutions for a seamless transition toward viable sustainable technologies.

INTRODUCTION

with the rapid growth of the global population, food security, food safety, and nutrition continue to remain key challenges globally. Access to safe and nutritious food is essential for sustaining life and public health. According to the World Health Organization (WHO 2024), foodborne illnesses affect approximately 1 in 10 individuals globally, resulting in around 420,000 deaths annually. Additionally, low- and middle-income countries incur economic losses amounting to $110 billion annually due to low productivity and medical expenses resulting from consumption of unsafe food (WHO 2024). According to the State Food Security and Nutrition in the World (SOFI) report, around 691 to 783 million people around the globe have experienced hunger in 2022. The increasing global demand for food safety, food security, and quality require advancement of innovative food processing technologies.

Ionizing radiation is an extremely safe and efficient non-thermal food processing technology that maintains nutritional value, texture, color, and taste of fresh and cooked foods. For more than a century, researchers have explored the use of ionizing radiation in agriculture and food processing. The first patents for the use of ionizing radiation to destroy microorganisms in food were granted in 1905 (Ehlermann 2016). Following World War II, there was a tremendous advancement in the study of radiation and its effects on food. President Dwight Eisenhower's "Atoms for Peace Program" in the 1950s gave the impetus to use of nuclear technologies for food, especially food irradiation (Ehlermann 2016; Pilat et al. 2019). According to the International Atomic Energy Agency (IAEA), over 50 countries have authorized the use of ionizing radiation for approximately 50 different food products, with 33 countries implementing food irradiation technology on a commercial level (IAEA 2020; NASEM 2021). Food irradiation serves multiple purposes, including reducing foodborne pathogens, shelf-life extension, delay in sprouting and ripening, and phytosanitary applications (USDA 2016). The “Atoms4Food” initiative by IAEA is a global effort aimed at leveraging nuclear technology to enhance food security, ensure food safety, and improve agricultural productivity, and food irradiation serves as a key component of this initiative (IAEA 2024).

The electromagnetic spectrum is comprised of both ionizing and non-ionizing radiation, which differ primarily in their energy levels. Food irradiation employs ionizing radiation that involves a significant amount of energy capable of ionizing the atoms, resulting in “ejecting electrons” from their orbital shells around the nucleus (Pillai and Shayanfar 2017). Traditionally, gamma irradiation from radioactive isotopes such as ⁶⁰Co and ¹³⁷Cs have been used primarily for food irradiation (Munir and Federighi 2020; Berrios-Rodriguez et al., 2022). However, machine source-based ionizing radiation technologies, such as electron beam (eBeam) and x-ray, have emerged as sustainable alternatives to gamma irradiation.

IONIZING RADIATION-BASED FOOD PROCESSING TECHNOLOGIES

As per the US FDA 21 CFR Part 179, the following ionizing radiation energy sources can be used safely for food treatment/ processing:

1. Gamma rays—Generated from sealed units of the radionuclides ⁶⁰Co or ¹³⁷Cs;

2. Electron beam—Electrons generated from machine sources at energy not exceeding 10 million electron volts (MeV); and

3. X-rays—Generated from machine sources at energies not exceeding 5 MeV or generated from machine sources using tantalum or gold as the target material and using energies not exceeding 7.5 MeV.

Table 1 provides the comparative differences between gamma radiation, eBeam, and x ray.

Table 1.

Comparative difference between gamma, electron beam and x-ray based ionizing radiation technologies.

Parameter	Gamma	Electron beam	X ray
Radiation Source	Radioactive isotopes (60Co, 137Cs)	Machine-generated high energy electrons	Machine-generated high energy electrons bombarding on heavy metal target
Energy profile	1.17 MeV and 1.33 MeV (60Co) 0.662 MeV (137Cs)	Below 300 keV (low energy) 300 keV to 5 MeV (medium energy) 5 MeV to 10 MeV (high energy)	80 keV to 7.5 MeV
Penetration depth	High	Moderate (depends upon energy levels)	Intermediate (higher than eBeam but lower than gamma)
Dose rate	Low dose rate (typically Gy h−1)	Very high dose rate (typically kGy s−1)	Lower, vary widely depending on x-ray conversion efficiency (typically Gy min1)
Processing speed	Slow (continuous exposure required)	Fast	Moderate (depends on x-ray beam power)
Shielding requirements	10–20 cm lead, 1–2 m concrete	30–50 cm concrete	10–20 cm lead, 1–2 m concrete
Regulatory complexity	High, strict regulations for sourcing, transport and disposal of radioactive material	Lower, no radioactive material, operational and safety standards adherence required	Moderate, regulatory approval required for shielding and safety compliance
Capital Equipment Cost	Approximately $15/Curie, Requires $15 Million for source alone	Approximately $20 million for turnkey facilities	Approximately $20 million-$30 million for turnkey facilities
Environmental impact	Radioactive waste disposal required, higher regulatory burden	No radioactive waste, More energy-efficient	No radioactive waste Less energy-efficient than eBeam

Gamma radiation

Gamma ray photons for food processing rely primarily on the radioactive decay of radioactive isotopes ⁶⁰Co and ¹³⁷Cs. The industrial facilities mainly use ⁶⁰Co, a manmade radionuclide produced when stable ⁵⁹Co is subjected to neutron bombardment in a nuclear reactor. This process converts ⁵⁹Co to ⁶⁰Co, which subsequently emits gamma radiation as it decays. Cobalt-60 emits gamma rays of two different energies of 1.17 MeV and 1.33 MeV (million electron volts) and emits low energy beta rays (electrons) with a maximum energy of 0.32 MeV (Cleland 2006; Munir and Federighi 2020). Cobalt-60 has a half-life of 5.26 y, and its activity decays by 12.53% per year. Hence, the total activity in the irradiation facility must be replenished by adding new ⁶⁰Co sources every year. Compared to ⁶⁰Co, ¹³⁷Cs is never used in food irradiation facilities owing to its extremely low dose rate and serious safety concerns associated with its potential use in “dirty bombs.” Cesium-137 is generated as a byproduct of nuclear fission of ²³⁵U in reactors and is extracted from the spent fuels. Cesium-137 emits gamma radiation with energy of ~0.662 MeV as it decays and has a relatively longer radioactive half-life of approximately 30.07 y (Snow and Snyder 2016). Cesium-137 is used primarily in blood irradiation.

In gamma radiation facilities, the radioactive sources are stored in deep water pools of about 8 m depth for ensuring safe containment between use. The products to be irradiated are exposed to gamma rays through a conveyor system with an intermittent supply system (Munir and Federighi 2020). The exposure duration varies depending on the product type, desired dose, and the efficiency of the irradiation facility. Certain facilities employ specialized multi-sided exposure to ensure delivery of desired radiation dose to the center of the product (Federighi 2019). The processing speed of the irradiator facility mainly depends on the dose rate (i.e., the rate at which the energy is deposited on the target material). The dose rate of gamma irradiation is significantly lower compared to commercial scale x-ray and eBeam facilities, resulting in slower throughput (Pillai and Shayanfar 2017). Products requiring irradiation are shipped to these core facilities for processing.

Electron beam

Electron beams (eBeam) are generated using electron accelerators, either pulsed linear accelerators (LINACs) or Rhodotron® (IBA, Louvain-la-Neuve, Belgium), which produce high energy electrons that can be used for various industrial and food processing applications. Unlike gamma radiation that is produced continually from a radioactive source, eBeam technology is “switch-on/switch-off” and can be switched on and off as needed (Pillai and Shayanfar 2017). The main components of electron accelerators include electron source, accelerator tube, and the scan horn (Miller 2005). In a pulsed linear accelerator, electrons are emitted from a heated cathode via thermionic emission. These emitted electrons are further accelerated within the accelerating structure under high vacuum. Electrons are accelerated to an energy proportional to the voltage used in the accelerator. These high energy electrons are further directed and shaped to form a beam using magnetic and electric fields to ensure uniform product coverage (Munir and Federighi 2020). The products to be treated are packaged and loaded on to a conveyor system that moves them through the eBeam treatment zone. With the movement of conveyors under the eBeam window, eBeam penetrates the product, delivering a controlled dose of ionizing radiation. The dose that is delivered to the product is inversely related to the speed of the processing table.

Based on the energy levels, electron beams are generally classified into Low Energy Electron Beam (LEEB), Medium Energy Electron Beam (MEEB), and High Energy Electron Beam (HEEB). These different energy levels determine their applications, interaction properties, and effectiveness in various industrial and medical scenarios. The LEEB typically operates at energies up to 1 MeV, has low penetration capability, and is generally used for surface treatments. MEEB (1 MeV–5 MeV) are suitable for specific packaging configurations and applications that require only a moderate penetration depth. High Energy Electron Beam (HEEB) technologies provide deeper penetration and encompass equipment that operates between 5 MeV and − 10 MeV. HEEB are ideally suited for industrial scale food processing and bulk sterilization. Compared to LEEB and MEEB, HEEB facilities require extensive shielding but are quite suitable for high throughput, large scale industrial processing. Table 2 provides a comparative analysis of high, medium, and low energy electron beams.

Table 2.

Comparative analysis of high energy (HEEB), medium energy (MEEB), and low energy electron beams (LEEB).

Parameter	HEEB	MEEB	LEEB
Energy range	5 MeV to 10 MeV	1 MeV to 5 MeV	Up to 1 MeV
Penetration depth	Deeper penetration (used for bulk processing)	Moderate (Depending on material density)	Lower, surface level only
Processing speed	Very fast	Very fast	Very fast
Shielding requirements	Extensive shielding with thick concrete and lead wall to prevent secondary radiation	Moderate shielding with lead or concrete for safety	Minimal shielding with stainless steel
Primary application	Industrial and medical device sterilization, food irradiation, Environmental remediation	Food irradiation, material modification, medical device sterilization	Surface sterilization, polymer curing, for sterile insect technology

Currently, there are different types of commercial eBeam accelerators available, such as DC (Direct current) accelerators, CW (Continuous Waveform) accelerators, and pulsed accelerators (Pillai and Shayanfar 2017). For obtaining high penetration of electrons during food processing, it is desirable to use accelerators with greater penetration power. Hence, 10 MeV HEEB accelerators (Rhodotron-based and LINAC-style) are increasingly finding application in food processing. For food processing, there is an upper limit on energy levels of eBeam at 10 MeV, as energy levels higher than 10 MeV could potentially induce trace levels of transient radioactivity in some materials with higher density (Miller 2005).

X ray

X rays can be generated using LINAC or Rhodotron-based accelerators. In a LINAC-based accelerator, x-ray generation relies on the process termed “Bremsstrahlung radiation,” where energetic electrons (typically 5 or 7.5 MeV) are directed onto a high atomic number material, such as tantalum or gold. The interaction between the high-energy electrons and the dense material results in the production of x-ray photons. These x-ray photons, like gamma radiation, possess significant penetrating power when compared to electron beams. However, the energy of x rays (5 or 7.5 MeV) is considerably higher than that of gamma rays from ⁶⁰Co sources (Miller 2005; Pillai and Shayanfar 2017). A significant advantage of x-ray photons over gamma photons is the dose rate. X rays can achieve a dose rate of approximately 100 Gy s⁻¹, which is much higher than the dose rate of gamma rays, which is about 100 Gy min⁻¹ (Hieke 2015). Compared to HEEB, x rays require longer processing time due to relatively lower dose rate and low efficiency in energy conversion. Only less than 10% of energy from the electron beam is converted to x ray, and the remainder is lost as heat or other forms of radiation (Fu et al. 2020). During x-ray generation, part of the beam energy produced is lost due to scattering and absorption processes before it penetrates the product. Conversely, in HEEB, the electrons are directly delivered to the product making them more efficient in terms of energy used and time taken for irradiation. However, the major advantage of x-ray based treatment is that the food products can be treated directly in their pallets rather than having the foods de-palletized if being treated with eBeam technology.

The Codex Alimentarius, the global organization established by the United Nations Food and Agricultural Organization (FAO) sets guidelines for the use of ionizing technology in the international trade of food. This organization has established a maximum 10 MeV energy for eBeam based food processing. In the US, eBeam energies up to 7.5 MeV can be employed to generate x rays for food irradiation. However, on a global scale, the maximum permissible energy for x rays remains limited to 5 MeV (Pillai and Shayanfar 2017).

MICROBIAL INACTIVATION MECHANISMS DURING IONIZING RADIATION

Regardless of whether the original source is gamma-ray photons, x-ray photons, or eBeam-based electrons, it is ultimately the electrons that drive the effectiveness of ionizing technologies. During food processing using ionizing radiation (gamma, eBeam, or x ray), photons or electrons first penetrate the packaging material before it reaches the food product. As ionizing radiation encounters the packaging components, ionization events occur within materials such as cardboard and plastic layers. This leads to the ejection of electrons from their atomic orbitals, which then collide with neighboring atoms, triggering a cascade of additional ionization events. Many of these primary and secondary electrons subsequently enter the food product. Upon entering the food, these energized electrons or photons initiate similar ionization events, interacting with both the liquid and solid components of the food matrix. When ionizing radiation interacts with water molecules, it induces ionization and hydrolysis, leading to the formation of highly reactive but short-lived free radicals, such as hydroxyl radicals and hydrogen peroxide. These free radicals contribute to further radiolysis and induce damage to microbial DNA, primarily through single- and double-strand breaks. This mechanism is referred to as indirect DNA damage, as it results from secondary reactive species rather than direct interaction with the DNA molecule. In contrast, direct DNA damage occurs when photons or electrons interact directly with microbial DNA, stripping away electrons from the DNA structure and causing strand breaks through direct ionization events. Both direct and indirect DNA damage contribute to microbial inactivation, ensuring the effectiveness of ionizing radiation in food sterilization and preservation (Miller 2005; Pillai and Shayanfar 2017).

The effect of ionizing radiation does not discriminate between pathogenic microbes, spoilage organisms, or naturally occurring food-associated microorganisms. The effect depends on the absorbed radiation dose, which is defined as the energy absorbed per unit mass of the material. Among the cellular biomolecules, DNA is the largest and most radiation-sensitive macromolecule that suffers damage due to extensive single and double-strand breaks. Microbial cells possess DNA repair mechanisms capable of repairing these strand breaks to a certain extent. Sensitive microorganisms such as E. coli cannot repair double-strand breaks in DNA, but highly radiation resistant organisms, such as Deinococcus radiodurans, are able to repair even double-strand breaks (Farkas 2007). However, with increase in radiation doses, DNA damage proportionally increases, resulting in more lethal double-strand breaks halting DNA replication and cell death. It is estimated that exposure to 1 kGy of ionizing radiation induces between 10 to 100 double-strand breaks per microbial cell. This extensive DNA fragmentation is a key reason why ionizing radiation reduces bacterial load, leading to an extended shelf life of food products (Miller 2005; Smith and Pillai 2004). With further increase in dose, ionizing radiation can also affect other cellular molecules such as cellular membranes, structural and functional proteins, enzymes, etc.

The relative resistance or sensitivity of microorganisms to ionizing radiation is determined by their decimal reduction dose (D-10 values). The D-10 value represents the radiation dose required to achieve a 90% reduction (equivalent to a 1-log decrease) in microbial populations. In commercial food irradiation, processing dose limits are established based on the desired level of microbial reduction. Several factors influence the D-10 value of microbes in food, primarily the physiological characteristics of microbial cells, physical state of the food, type of food, food packaging conditions, and physiological state of the microbe (Praveen et al. 2013). Different microorganisms exhibit varying sensitivity to ionizing radiation. The difference in D-10 value between gram negative and gram-positive bacteria can be due to the difference in cell wall structure and repair mechanisms. Viruses have significantly higher D-10 value than bacterial cells owing to their smaller size, structural differences, and lack of DNA repair mechanisms (Zhou et al. 2011; Praveen et al. 2013). Food matrix composition significantly impacts the microbial D-10 values, with foods rich in fats and proteins protecting microbial cells from damage by interacting with radiolytic species and scavenging the Reactive Oxygen Species and reducing the overall effect of radiation (Moreira et al. 2010). Higher water activity levels in food can increase the microbial susceptibility to radiation by lowering D-10 value due to enhanced formation of free radicals. Refrigerated temperatures generally allow better absorption of radiation by microbes due to increased molecular mobility and interactions with free radicals, whereas in frozen products, the water and cellular molecules are immobilized and require relatively higher doses for microbial inactivation (Sommers and Niemira 2007). Table 3 provides a selected list of D-10 values of microorganisms showing the variation depending upon pathogen type, product temperature, and packaging conditions.

Table 3.

D-10 value variation as a function of pathogen, food product, product temperature, and packaging conditions compiled from published literature.

Food Product	Temperature condition	Pathogen	D-10 value (kGy)
Ground beef	Refrigerated	E. coliO157:H7	0.25-0.30
Ground beef	Frozen	E. coliO157:H7	0.45-0.48
Ground beef patties	Refrigerated	E. coliO157:H7	0.27-0.38
Ground beef patties	Frozen	E. coliO157:H7	0.32-0.63
Ground beef	Refrigerated	Salmonella spp.	0.48-0.61
Ground beef	Frozen	Salmonella spp.	0.70-0.82
Ground beef	Refrigerated	Listeria monocytogenes	0.40-0.50
Ground beef	Frozen	Listeria monocytogenes	0.64-0.91
Ground beef	Refrigerated	Campylobacter jejuni	0.18
Ground beef	Frozen	Campylobacter jejuni	0.24
Beef	Refrigerated	Yersinia eneterocolitica	0.10-0.21
Beef	Refrigerated	Staphylococcus aureus	0.46
Deboned meat	Refrigerated	B. cereus spores	2.56
Whole Oyster	Refrigerated	Hepatitis A virus	4.83
Whole Oyster	Refrigerated	Murine Norovirus	4.97
Spinach	Refrigerated	Rotavirus	1.29
Spinach	Refrigerated	Poliovirus	2.35
Lettuce	Refrigerated	Rotavirus	1.03
Lettuce	Refrigerated	Poliovirus	2.32
Poultry meat	Refrigerated	Low Pathogenic Avian Influenza virus	2.6
Poultry (air packed)	Refrigerated	Salmonella heidelberg	0.24
Poultry (vacuum packed)	Refrigerated	Salmonella heidelberg	0.39

In summary, the D-10 value varies across different pathogens following this trend: spores exhibit the highest resistance, followed by viruses, gram-positive bacteria, gram-negative bacteria, and finally vegetative states of yeasts and molds, which are the most sensitive. Food products with higher fat or protein content tend to have greater D-10 values compared to those rich in water or acidic components, as fat and protein provide a protective effect. Similarly, frozen foods display higher D-10 values than those that are chilled or stored at room temperature, due to reduced free radical mobility at lower temperatures. Additionally, products stored in vacuum-sealed or modified atmosphere packaging (MAP) generally have higher D-10 values compared to those in oxygen-rich packaging, as the absence of oxygen reduces oxidative damage from free radicals.

APPLICATION OF ELECTRON BEAM AND X-RAY IN AGRICULTURE AND FOOD PROCESSING

Preharvest applications

Even though ionizing radiation is primarily associated with post-harvest food processing, such as microbial inactivation and shelf-life extension, there is continuing and emerging interest in its use in preharvest applications to enhance food safety, crop yield, and animal health. Electron beam and x-ray technology offers innovative approaches to enhancing seed germination, modifying plant traits, and controlling pests and diseases contributing toward sustainable agricultural practices.

Seed treatment for enhanced germination

Electron beams are now being used to treat seeds before planting to reduce microbial populations effectively (such as bacteria and fungi) that could inhibit seed germination and plant growth. At a dose below 2 kGy, eBeam treatment was found to be effective in eliminating fungal pathogens Botrytis cinerea and bacterium Agrobacterium rhizogenes in vegetable seeds without affecting germination rate (Bae 2013). Studies have shown that low doses of eBeam/x-ray enhanced seed viability and germination by stimulating enzyme activities, increasing crop growth ( Rodthaing et al. 2024). Lower doses of eBeam have been found to stimulate the germination process by triggering metabolic activity in seeds without causing any significant cellular harm (Tosri et al. 2019). Low dose eBeam induced enhanced chlorophyll content, nutrient absorption, and stimulated growth rate in Curcuma sp. (Rodthaing et al. 2024). Salmonella and E. coli O157:H7 have been associated with foodborne outbreaks linked to raw sprouts in multiple countries. Ionizing radiation treatment of around 2 kGy was effective in controlling these pathogens on seeds (Taormina et al. 1999).

Mutation breeding

Mutagenesis has been used in crop production with the objective of generating a diverse range of mutants to identify beneficial traits that can enhance yield and quality. Crop mutation is achieved using chemical methods and physical methods including ionizing radiation treatment of seeds. The occurrence of double-strand DNA breaks during exposure to electrons or photons is the primary mechanism behind these mutations. The G value, which quantifies the frequency of double-strand breaks, is 5.7 times higher for eBeam compared to gamma radiation at the same dose (Gowthami and Arumugam Pillai 2017). These findings suggest that eBeam irradiation is more effective in inducing seed mutagenesis than gamma radiation. Controlled exposure to low dose eBeam induces genetic mutation in plants leading to desirable traits such as disease resistance, drought tolerance, and improved yield (Dhole et al. 2023).

Sterile insect technique

Another major preharvest application of ionizing radiation is to reduce the insect pest population and reduce the risk of diseases and crop damage in the field. The Sterile Insect Technique (SIT) employs ionizing radiation to sterilize mass reared insects before they are released into the environment. At optimal doses, radiation damages the insect’s genetic material, leading to dominant lethal mutations that prevent reproduction. Only male insects are sterilized and released to the field where they compete with wild males for mating while producing non-viable offspring, leading to population decline in successive generations (Wilcox et al. 2022). Studies have demonstrated SIT as an effective method to manage a number of fruit fly species (Ceratitis capitata), pink bollworm (Pectinophora gossypiella), coddling moth (Cydia pomonella), new world screw worm (Cochliomya homnivorax), and mosquitoes (Aedes aegypti) (Bakri and Hendrichs, 2022; Wilcox et al. 2022; Ranathunge et al., 2022; Bourtzis and Vreysen, 2021).

Post harvest applications

Food Safety

Electron beam and x-ray technologies find major applications in food safety to ensure microbial decontamination, improve shelf life, and enhance product quality. Being a non-thermal food processing method, they help to eliminate pathogens and spoilage microorganisms without altering sensory and nutritional attributes of food products. While processing food using ionizing radiation, the minimum absorbed dose should be sufficient to achieve the purpose of application (pathogen elimination or phytosanitary), and the maximum absorbed dose must not compensate for the structural integrity, smell, or taste (Smith and Pillai 2004). Microbial contamination can happen at various stages of food production, processing, and distribution starting from farms, slaughterhouses, processing facilities, retail environment, and even at home. Improper handling and storage of meat products further elevates the risk of contamination. It is estimated that approximately 18 million pounds of ground beef undergo commercial irradiation in the US for retail and foodservice purposes, and around 50% of this volume is processed using eBeam technology (Pillai and Shayanfar 2017). eBeam treatment serves as an effective intervention method in the case of packaged beef products, poultry products, and fresh produce, as it significantly reduces foodborne pathogens such as Shiga toxin producing E. coli (STEC), Salmonella spp., and Listeria monocytogenes (Clemmons et al. 2015; Indiarto et al. 2023). Thus, eBeam processing can be recognized as a final Critical Control Point (CCP) within a validated Hazard Analysis and Critical Control Point (HACCP) system. In the case of ground beef, sanitation of the beef carcass is conventionally done using acid sprays such as lactic acid sprays. These surface sprays are ineffective on pathogens that are already internalized within the meat. When employing eBeam processing, the final packaged ground beef treated with eBeam effectively inactivates pathogens without affecting the sensory qualities of the product (Indiarto et al. 2023). It is to be noted that eBeam-based processing is to be integrated only as final step in food processing together with employing good agricultural and handling practices, not merely as a “clean-up” technology. This allows minimizing the irradiation dose, offering multiple benefits including reduced processing cost, higher safety margin, and increased throughput efficiency. Table 3 provides the list of pathogens associated with food items that can be inactivated effectively at different doses of ionizing radiation.

Animal feed and pet food are another class of food permitted to receive ionizing radiation treatment. Given that many animal feed products contain raw meat, irradiation serves as an essential measure to mitigate the risk of foodborne illnesses in livestock and domestic pets. With the prohibition of antibiotics as feed additives, ionizing radiation presents a viable alternative for enhancing the microbial safety of animal feed (Wei et al. 2023). Although sensory changes are less critical for animal feed, they are essential to maintain the nutritional profile. Studies show that irradiated pet food meets nutritional requirements while also reducing pathogens present, depending on the food composition and absorbed dose (Kakatkar et al. 2024). Table 4 provides a list of food items and irradiation doses used for various applications.

Table 4.

Different dose levels of ionizing radiation and their application in food processing.

Dose Level (kGy)	Purpose	Food Items
Low Dose (Up to 1 kGy)
0.06-0.2	Inhibit Sprouting	Potatoes, Onions, garlic, ginger root
0.15-1.0	Insect and parasite disinfestation	Cereals and pulses, fresh and dried fruits. Dried fish and meat, fresh pork, etc.
0.15-1.0	Delay in ripening	Fresh fruits and vegetables
Medium dose (1-10 kGy)
1.0-7.0	Extension of shelf life	Fresh fish, shellfish, strawberries etc.
1.0-7.0	Elimination of pathogen and spoilage microorganisms	Fresh and frozen sea food, raw or frozen poultry and meat and fresh produces.
3.0-7.0	Improving the technological property of food	Grapes (increase juice yield), dehydrated vegetables (reduce cooking time)
High dose (10-50 kGy)
10-25	Industrial sterilization	Packaging materials
30	Decontamination of certain food additives, spices	Spices, dry vegetable seasonings Natural gum etc.
44	Food Sterilization (For National Aeronautics and Space Administration NASA, and hospitals)	Packaged food

Shelf-life extension

Food irradiation is a proven method for extending the shelf life of various food products by reducing microbial contamination, delaying spoilage, and maintaining overall product quality. Ionizing radiation, such as gamma rays, eBeam, and x rays effectively eliminates or reduces spoilage microorganisms, including bacteria, molds, and yeasts, which are primary contributors to food deterioration (Smith and Pillai 2004). In perishable foods such as meat, poultry, and seafood, irradiation at doses between 1 and 3 kGy significantly reduces spoilage bacteria, extending refrigerated shelf life from 7 to 21 days (Farkas and Mohácsi-Farkas 2011). Additionally, in fruits and vegetables, irradiation at 0.15 to 1 kGy slows down ripening processes by inhibiting enzymatic activity and delaying senescence, effectively prolonging market freshness (Smith and Pillai 2004).

Application of low-dose irradiation (≤0.15 kGy) effectively inhibits sprouting in crops such as potatoes, yams, onions, garlic, ginger, and chestnuts. This ensures a consistent year-round supply of potato tubers, onion bulbs, yams, and other sprouting plant-based foods and enables long-term storage. Irradiation treatment replaces the use of chemical sprout inhibitors such as maleic hydrazide, propham, and chloropropham that can leave chemical residues in the food causing health concerns. Additionally, these low dose irradiated produces can be stored at high temperatures such as 10-15 °C maintaining superior processing characteristics without the need for refrigeration during storage and thereby lowering storage cost (Rezaee et al. 2013).

Decontamination of spices

Spices are the largest group of food items that are processed using ionizing technology. Spices are not only used in food but also in cosmetics and pharmaceutical industries. Many kinds of microorganisms cause spoilage of spices, and consumption of these contaminated spices is dangerous for health. Throughout the processing stages, spices and herbs can become contaminated with various bacteria and molds from sources such as soil, insects, birds, or rodents (Pillai and Shayanfar 2017). Microorganisms such as Salmonella spp., Bacillus cereus, and Clostridium perfringens, as well as molds and mycotoxins, are big concerns in the spice industry, as even small amounts can cause adverse effects on public health (Farkas 2006; Calado et al. 2014). The application of Low Energy Electron Beam (LEEB) in decontamination of spices was found to be efficient in inactivating Salmonella spp. in black peppercorns (Murdoch et al. 2022). Table 4 provides the dose level for decontamination of spices and additives.

Reduction of toxins

Ionizing radiation can break down bacterial toxins, mycotoxins, and pesticide residues in food without heat application. The mechanism of toxin reduction involves radiolytic cleavage and oxidative breakdown, leading to the formation of less harmful byproducts (Pillai and Shayanfar 2017). Regulatory organizations, such as the WHO, FAO, and FDA, recognize irradiation as a safe and effective method for food detoxification with no residual radiation or adverse effects on nutritional quality. Studies have shown that irradiation doses between 5 and 10 kGy can reduce mycotoxins dramatically, including aflatoxins, ochratoxins, and fumonisins, which are frequently found in grains, nuts, and dried fruits. Aflatoxin levels can be reduced by up to 80% (Calado et al. 2014). Similarly, irradiation doses of 2 to 5 kGy have been shown to inactivate bacterial toxins, including Staphylococcus aureus enterotoxins and Bacillus cereus cereulide toxins, by disrupting their molecular structures and reducing their toxicity (Farkas and Mohácsi-Farkas 2011). Despite its proven benefits, optimizing irradiation doses for different food matrices remains an important area of research to maximize safety while preserving sensory attributes.

Phytosanitary application

Phytosanitary measures are designed to safeguard domestic agriculture from invasive pests that may be introduced through the international trade of fresh fruits, vegetables, and other food commodities. These products can serve as hosts for a variety of insect pests, which, if not effectively managed, have the potential to spread and cause significant economic damage. Among the most common pests of concern in fresh produce transportation are fruit flies, butterflies, moths, and mealybugs. The primary objective of phytosanitary treatment is not necessarily to destroy pests but to disrupt their development or reproductive capability, thereby preventing their establishment and spread (Barkai-Golan and Follet 2017). Low doses of irradiation are used to increase shelf life and decrease microorganisms that cause foodborne illness without negative effects on the product. Low doses may not be lethal for the pathogenic microorganisms present in a product, but the sub-lethal doses can delay fungal growth and increase shelf life (Barkai-Golan and Follet 2017). Phytosanitary treatments can be administered at the country of origin, upon arrival at the destination port, or during transit, depending on regulatory requirements and logistical considerations. These treatments play a crucial role in maintaining biosecurity while facilitating international trade.

RATIONALE FOR REPLACING ⁶⁰Co WITH ALTERNATIVE TECHNOLOGIES

Over the past two decades, the use of eBeam technology for food and industrial sterilization has grown significantly both in the US and globally. Alternative technologies for food irradiation, phytosanitary treatments, and insect sterilization are increasingly accepted as viable replacements for radioactive sources in many countries (NASEM 2021). The transition from ⁶⁰Co irradiators to alternative radiation technologies, particularly eBeam and x-ray, is driven by multiple factors related to global supply of radioactive sources, radiation safety and security, effectiveness, costs, and technological advances.

Radioactive source supply, security and regulatory concerns

Gamma irradiators require a radioactive source, typically ⁶⁰Co or ¹³⁷Cs, which needs to be replenished frequently, depending on the half-life, to maintain the total activity of the radioactive source (Demirci et al., 2020). Traditionally, the food and agricultural products treated by irradiation are processed in facilities using gamma radiation from ⁶⁰Co. These facilities are typically multipurpose in nature and are designed primarily for the sterilization of medical devices rather than dedicated food irradiation centers. The use of gamma irradiation for food presents challenges related to security, cost-effectiveness, and resource availability. Furthermore, multipurpose irradiation facilities are generally optimized for medical applications, making them less suitable for countries struggling with food security. Consequently, there has been a decline in the construction of new ⁶⁰Co-based facilities for food irradiation (NASEM 2021).

There are two primary types of gamma irradiators: underwater and wet-storage panoramic models. In the case of underwater irradiators, the sealed radioactive sources always remain submerged in water, which serves as a shielding barrier to protect workers and the public from radiation exposure. Products requiring irradiation are placed in waterproof containers, lowered into the irradiator pool, exposed to radiation, and subsequently removed after processing. The Wet-source-Storage Panoramic Irradiators also store radioactive sources underwater when not in use. However, during operation, these sources are raised into the irradiation chamber to irradiate products, which are transported into the irradiation chamber via an automated conveyor system. To ensure radiation protection when the sources are elevated, the irradiation chamber is enclosed with thick concrete or metal shielding (US NRC 2008). The US Nuclear Regulatory Commission (US NRC) oversees commercial irradiator facilities in the US, and strict safety controls and handling procedures are implemented for all irradiators to minimize risk of occupational radiation exposure. The IAEA has published specific safety standards to assist member countries in harnessing this technology (IAEA 2010). The waste associated with gamma irradiation is labeled Class C, which requires strict regulation for disposal (NRC 2008). Removal and transportation of waste also increase environmental risks.

Replenishing the radioactive source is a major downside of gamma irradiation, as it is costly, and there are only a few providers worldwide. There is a widening gap between the global demand and supply of ⁶⁰Co. Production of ⁶⁰Co isotope is concentrated in a limited number of reactors in Argentina, Canada, China, India, and Russia, but most of the ⁶⁰Co produced in China and India and a portion from Argentina is reserved for local use. Consequently, the global supply originates primarily from Canada and Russia, with a single Canadian manufacturer supplying majority of the international market (WNN 2023). Reliance of few specialized suppliers increases the vulnerability to supply chain disruption. Despite rising demand, ⁶⁰Co production has faced disruptions, including reduced output from a Russian reactor and temporary shutdowns of Canadian and Argentine reactors for refurbishment. Reactor refurbishment is essential for extending operational lifespans enabling continued ⁶⁰Co production for the next 25-30 y. While some production reactors have permanently closed, some new and refurbished reactors are operational, such as Russia’s Leningrad nuclear power plant, Canada’s Pickering reactors, and Ontario Power Generation's (OPG) Darlington reactors, for ⁶⁰Co isotope production. Currently approximately 440 commercial nuclear reactors are in operation with over 300 pressurized water reactors, which are primarily focused on ⁶⁰Co production (WNN 2023). However, the production capacity of these reactors is insufficient to meet the global demand for ⁶⁰Co.

Regulatory agencies such as IAEA, NRC, and other national nuclear safety authorities enforce stringent safety and security protocols for transportation and handling of ⁶⁰Co and ¹³⁷Cs. Both ⁶⁰Co and ¹³⁷Cs are categorized as high-risk radioactive materials and if stolen could be used in Radiological Dispersal Devices (RDDs) or “dirty bombs,” posing a national security risk (Gonzalez 2001; NRC 2008). Inadequate shielding during transport could lead to excessive radiation doses for transport personnel and the public. If a radioactive source is damaged during transport, contamination could spread to air, soil, and water, leading to long-term environmental and health consequences. Particularly, ¹³⁷Cs (being water-soluble) is more prone to environmental dispersion in case of a leakage. Radioactive materials must be transported in robust, specially designed Type B(U) or Type B(M) casks, which are engineered to withstand severe accidents (e.g., fire, impact, water immersion) (US DOT 2008; NRC 2008). During transportation, real-time tracking and secure transport routes are mandated and require authorized or trained personnel to handle and transport the materials. Periodic leak tests and source integrity assessments are required before transportation, and facilities must maintain decontamination protocols and emergency response teams trained in radiation hazard mitigation. The IAEA, NRC, and other regulatory agencies also maintain databases like Incident Trafficking Database (ITDB) to track any lost, stolen, or mishandled radioactive sources. Therefore, the rising cost of the radioactive isotope, coupled with security and regulatory requirements and the limited options associated with disposal of spent radioactive material, make ⁶⁰Co as a technology for agriculture and food processing uneconomical and unsustainable.

Unlike gamma irradiation, which relies on radioactive isotopes, neither eBeam nor X-ray technologies use radioactive sources. Instead, they use commercial electricity to generate energetic electrons or photons (Miller 2005; Pillai and Shayanfar 2015). This reduces the complexities involved in the supply chain and eliminates the need for strict security measures associated with transporting and storing radioactive materials. Compared to gamma, eBeam processing has quick turnaround time due to higher dose rate. Also, there is no discernable difference in the microbiological and material effects between gamma and eBeam; hence, the transition to eBeam processing does not affect the effectiveness of treatment (Demirci et al. 2020). Facilities operating eBeam or x-ray systems face fewer regulatory hurdles compared to those handling radioactive isotopes, lowering the operational burdens on facilities and aligning with sustainability goals in food processing (NASEM 2021).

CURRENT STATUS

The potential of using ionizing radiation for food processing is still largely untapped within food processing industries. Regardless of the food product or application, US FDA regulates the use of radiation in food processing as a “food additive,” rather than a physical process. In the US, food irradiation is governed by the 1958 Food Additives Amendment of the Food Drug and Cosmetic (FD & C) Act, with oversight shared with the US Department of Agriculture (USDA). The FDA has determined that gamma irradiation (using ⁶⁰Co or ¹³⁷Cs), x-ray, and eBeam technologies are equally safe and effective for approved food irradiation applications, including pathogen reduction and phytosanitary treatments (USDA 2016; NASEM 2021). Additionally, the FDA has established labeling requirements for irradiated foods, mandating the use of the international Radura symbol along with an appropriate statement on the food label. While bulk foods such as meat, eggs, fruits, and vegetables must display the Radura symbol, individual irradiated ingredients in multi-ingredient products, such as spices, are not required to be separately labeled. This designation has imposed regulatory challenges on the food processing industry in adopting food irradiation.

Ionizing radiation-based food processing has been approved in around 40 countries, though its application still remains rather limited and varies significantly in acceptance across different regions. The FDA has authorized the irradiation of various food products in the US, including beef, pork, poultry, crustaceans, fresh fruits and vegetables, shell eggs, and spices and seasonings. Among these, spices are the largest category of irradiated food. Table 5 provides the list of food items, and the maximum allowable dose permitted for ionizing radiation treatment in the US by FDA. The European Food Safety Authority (EFSA) regulates food irradiation in the European Union and the national authorities of each EU member state are also responsible for enforcing these regulations. In 2011, EFSA recommended food irradiation for pathogen reduction in food that can be integrated into a multi hurdle strategy for assuring public health protection (EFSA 2011). Food items such as poultry, fish, frog legs, dehydrated products, and herbs and spices can be commercially irradiated in the EU. Table 6 provides a list of food items commercially irradiated in EU countries.

Table 5.

List of food items authorized for ionizing radiation treatment in the US as per FDA [21 CFR 179.26(b)] and other federal documents (As of February 2025).

Food Product	Irradiation Application	Irradiation dose limitation (kGy)
Fresh, non-heated processed pork	Pathogen control	0.3-1.0
Fresh/frozen uncooked poultry products	Pathogen control	3
Refrigerated, uncooked meat products (sheep, cattle, swine, and goat)	Pathogen control	4.5
Frozen uncooked meat products (sheep, cattle, swine, and goat)	Pathogen control	7
Fresh/frozen molluscan shellfish	Pathogen control	5.5
Fresh shell eggs	Pathogen control	3
Seeds for sprouting	Pathogen control	8
Fresh iceberg lettuce and fresh spinach	Pathogen control and shelf-life extension	4
Frozen/chilled/dried cooked or partially cooked crustaceans with or without spices	Pathogen control and shelf-life extension	6
Dry or dehydrated spices and food seasonings	Microbial disinfection	30
Dry/dehydrated enzyme preparations	Microbial disinfection	10
Wheat flour	Mold control	0.5
Fresh produce	Growth and maturation inhibition	1
White potatoes	Sprouting inhibition	0.15
Fresh produce	Insect disinfestation	1
Frozen, packaged meats for NASA space flight programs only	Sterilization	44 (minimum dose)
Pet food, animal feed	Pathogen control and shelf-life extension	50

Table 6.

List of food items commercially irradiated in EU countries (For 2020-21)

EU Country	Food and Food ingredients irradiated	Absorbed dose (kGy)
Belgium	Dehydrated blood, plasma, coagulates	1.0-4.9
	Frozen frog legs	3.62-4.22
	Poultry	3.2-3.49
Czech Republic	Aromatic herbs, spices and vegetable seasoning (dried)	2.98-9.97
Croatia	Aromatic herbs, spices and vegetable seasoning (dried)	Data Not Available
Germany	Aromatic herbs, spices and vegetable seasoning (dried)	5
Estonia	Aromatic herbs, spices and vegetable seasoning (dried)	8-10
Spain	Aromatic herbs, spices and vegetable seasoning (dried)	8.6-9.6
France	Aromatic herbs, spices and vegetable seasoning (dried)	7.5
	Frozen frog legs	5
Hungary	Aromatic herbs, spices and vegetable seasoning (dried)	2-10
The Netherlands	Aromatic herbs, spices and vegetable seasoning (dried)	2.3-15
Poland	Aromatic herbs, spices and vegetable seasoning (dried)	5-10

China is currently the largest producer and consumer of irradiated food in the world, processing over 1 million tons annually (Wang et al. 2023).² As part of its strategic economic development and technological transformation program, there has been strong encouragement from the Chinese government in adopting eBeam technology as an alternative to ⁶⁰Co. Table 7 provides a list of food items and irradiation dose limits allowed as per the health standards of food irradiation in China (Wang et al. 2023). In India, commercial food irradiation is covered under Food Safety and Standards (Food Products Standards and Food Additives) regulations. The list of food items that can be irradiated as per the standards of Food Safety and Standards Authority of India (FSSAI) (Pillai and Shayanfar 2017) are provided in Table 8.

Table 7.

List of food items authorized for ionizing radiation treatment in China as per the GB 14891-1997.

Type of Food	Purpose of Irradiation	Absorbed dose (kGy)
Beans, grains and their products	Pest Control	0.2-0.6
Fresh fruits and vegetables	Sprouting inhibition, shelf-life extension	1.5
Cooked meat and poultry	Microbe control, shelf-life extension	8
Packed frozen meat of livestock and poultry	Microbe control	2.5
Packed frozen fish and shrimp	Microbe control	2.5
Dried spices, dehydrated vegetables	Pest control. Mildew proof	10
Nuts and preserved food	Pest control, shelf-life extension	1
Hog carcass	Microbe control, shelf-life extension	0.65
Pollen	Mildew proof, shelf-life extension	8

Table 8.

List of food items and irradiation dose limits allowed in India as per FSSAI standards, 2016.

Class	Food Product	Irradiation Application	Irradiation dose imitation (kGy)
1	Bulbs, stem, root tubers and rhizomes	Inhibit sprouting	0.02-0.2
2	Fresh fruits and vegetables	Delay ripening	0.2-1.0
		Insect disinfestation	0.2-1.0
		Shelf-life extension	1.0-2.5
		Quarantine application	0.25-1.0
3	Cereals and their milled products, pulses and their milled products, nuts, oil seeds, dried fruits, and their products	Insect disinfestation	0.25-1.0
		Bioburden reduction	1.5-5.0
4	Fish, aquaculture, seafood and their products (fresh or frozen), and crustaceans	Pathogen elimination	1.0-7.0
		Shelf-life extension	1.0-3.0
		Control of human parasites	0.3-2.0
5	Meat and meat products including poultry (fresh and frozen) and eggs	Pathogen elimination	1.0-7.0
		Shelf-life extension	1.0-3.0
		Control of human parasites	0.3-2.0
6	Dry vegetables, seasonings, spices, condiments, dry herbs and their products, tea, coffee, cocoa, and plant products	Microbial Decontamination	6.0-14.0
		Insect disinfestation	0.3-1.0
7	Dried foods of animal origin and their products	Insect disinfection	0.3-1.0
		Control of molds	1.0-3.0
		Pathogen elimination	2.0-7.0
8	Ethnic foods, military rations, space foods, ready-to-eat, ready-to-cook, and minimally processed foods	Bioburden reduction	2.0-10.0
		Quarantine application	0.25-1.0
		Sterilization	5.0-25.0

Globally, the trade of irradiated food products, especially for phytosanitary purposes has increased significantly, from approximately 5,000 tons in 2007 to over 45,000 tons in 2019 (NASEM 2021). This growth has been driven primarily by countries that require irradiated products for domestic consumption or seek to expand their market access internationally. Notable examples include Australia, India, Thailand, and Vietnam. In The US, phytosanitary regulations are established and enforced by the USDA-Animal and Plant Health Inspection Service (APHIS) in collaboration with state partners. There are three US facilities (two eBeam and one ⁶⁰Co) that are approved by USDA-APHIS to use ionizing technology for phytosanitary import/export purposes. Additionally, one Co-60 and one x-ray facility are designated for treating regional shipments (NASEM 2021). Countries that import fresh commodities treated with irradiation include the United States, Australia, Indonesia, Malaysia, Mexico, New Zealand, and Vietnam. Given these trends, the use of irradiation for phytosanitary applications is expected to continue expanding in these and other regions in the coming years.

Currently, there are around 300 gamma irradiator facilities worldwide in more than 50 countries that are majorly focused on medical device sterilization. With increasing concerns about ⁶⁰Co availability and Ethylene oxide (EtO) emissions, there is an increased global pressure to shift to alternative technologies such as eBeam and x-ray technologies (NASEM 2021). China is one of the biggest investors in eBeam specifically for food irradiation. According to the Nuclear and Radiation Safety Center, Sichuan Institute of Atomic Energy, Chengdu, China, there has been a steep increase in the eBeam accelerators operational in China, from 600 in 2020 to 1,100 accelerators in 2024. There are approximately 10 accelerator manufacturers in China presently manufacturing Low Energy Electron Beam (LEEB), Medium Energy Electron Beam (MEEB), High Energy Electron Beam (HEEB), and High Energy X-ray (HEEX) technologies. It has been estimated that there will be installation of additional 200-400 eBeam facilities globally in the next 10 y (NASEM 2021). The IAEA maintains a database with information on gamma, eBeam, and x-ray irradiators around the world called Database on Industrial Irradiation Facilities (DIIF). The DIIF tool helps organizations and companies to identify irradiator facilities suitable for irradiation of their products. This tool also helps research groups and experts to find collaboration and training opportunities (IAEA 2020).

APPARENT HURDLES IN TRANSITION TO ALTERNATIVE TECHNOLOGIES IN FOOD PROCESSING

Cost—capital expense

Shifting from gamma irradiation to alternative technologies requires significant facility modifications, incurring substantial transition costs. These costs vary depending on whether a facility is:

• Converting an existing ⁶⁰Co facility to eBeam or x ray;

• Constructing a new eBeam or x-ray facility; and

• Implementing a hybrid approach, where an eBeam or x ray is integrated into an existing ⁶⁰Co facility.

Economic and operational considerations affect the decision-making process while evaluating the feasibility of adopting alternative technologies by industries. Traditionally, food irradiation facilities were built by the government in different countries. However, it is unrealistic for government organizations to continue investing in multimillion dollar facilities. Meanwhile private enterprises are increasingly investing in eBeam and x-ray facilities for food processing in the US, Latin America, Mexico, China, India, Pakistan, Thailand, South Korea, and Australia. For private investment groups, spending $20-40 million is a relatively small investment as compared to investing in upscale hotels and resorts, which often cost upwards of $80 million. Therefore, capital investment in this technology is really a non-issue. The real challenge is identifying those private investment groups that are willing to learn about these technologies and make smart investments. To address the costs associated with establishing eBeam/x-ray facilities, the National Center for Electron Beam Research (NCEBR) at Texas A&M University, in partnership with National Nuclear Security Administration (NNSA)–Office of Radiological Safety (ORS) and Pacific Northwest National Laboratory (PNNL), is conducting financial feasibility and technical feasibility analysis for several countries around the world. These studies will help to evaluate the cost, benefits, and challenges in transitioning to non-radioactive alternatives in developing countries.

Unfamiliarity with alternative technologies

The majority of facilities employing ionizing technology are multipurpose contract-based facilities, which mainly focus on medical device/medical supplies sterilization. Hence, all the focus on transition is majorly focused on the medical device sterilization industry due to its high value. Cobalt-60-based gamma irradiators have been used widely for decades, leading to an extensive knowledge in this field. Comparatively, there is limited data on sterilization via eBeam and x-ray technologies. Manufacturers considering a shift to these alternative technologies must assess sterilization efficacy, material and packaging compatibility, and conduct revalidation studies to ensure equivalence in microbial inactivation. Hence, there is a great need to familiarize decision makers in government agencies, private industries, and investors in alternative technologies. To address this challenge, NCEBR is organizing several workshops, in-country workshops, outreach activities, and technical seminars customized for decision makers in different countries. Additionally, NCEBR organizes annual hands-on training workshops on eBeam and x-ray technologies for entrepreneurs, industrial professionals, and government and academic researchers. The Texas A&M University, Department of Food Science & Technology, also provides training to undergraduate and graduate students who can then serve as skilled workforce in handling eBeam and x-ray technology.

Electrical utility needs

There is a general assumption that the electrical utility requirements of eBeam and x-ray facilities are extremely large, but the amount of electricity and water required for such a facility is less than that of a typical data center. PNNL, along with TAMU NCEBR, are performing several electrical infrastructure and resiliency studies in different parts of the world. To date, these studies show that eBeam and x-ray facilities can be constructed and effectively operated all around the world, provided these facilities are designed with appropriate hardware and software to deal with brownouts, voltage spikes, and perturbations. These unpublished studies also show that these facilities can be designed to operate solely on either solar or battery power. For example, in the Dominican Republic, there is an eBeam facility (for medical device sterilization) that is operating solely on diesel generators.

Consumer acceptance

For a long time, the issue of consumer acceptance was used as an excuse for the relatively small amount of food that is treated with ionizing technology. However, data from China and India belie that consumers will not accept food treated with ionizing technology (Wang et al. 2023). Retail sales from US grocery stores over the last decade show that the amount of irradiated fresh produce sold is increasing by double digit numbers year after year. Studies have shown a willingness to purchase irradiated food and a positive trend in acceptance among consumers, especially when educated about its benefit and safety (Howie and Pillai 2025; Nayga et al. 2005). Therefore, the argument that consumers will not accept the food marked with “irradiation” is erroneous. According to the USDA-APHIS PPQ Phytosanitary program, approximately 48 million kg of food products entered the US from overseas in 2022, which is a significant increase from 13.6 million kg in 2014 (Pillai and Shayanfar 2017). This growth highlights the increase in use of ionizing technologies for agriculture and food processing.

CONCLUSION

Alternative ionizing technologies, eBeam and x ray, offer significant advantages over ⁶⁰Co-based gamma technology, including enhanced safety, regulatory flexibility, and environmental benefits. However, the adoption of technology is very slow in many parts of the world including the US. The regulatory framework associated with ionizing technologies for use in the food industry has to be upgraded to align with technological advancements. Countries like China, India, and Brazil have implemented more liberalized and streamlined regulatory policies leading, to accelerated adoption of these alternative technologies. China has now emerged as the biggest investor and user of eBeam technology for food processing. Establishing dedicated eBeam facilities for food processing, particularly in states with high fresh produce production like California and Arizona, could drive wider adoption of alternative technology in the US. Regulatory review of labeling terminology of food processed through alternative technologies as “eBeam pasteurized/eBeam processed” could improve public perception and wider consumer acceptance. Additionally, collaborative initiatives should be implemented to enhance awareness among key stakeholders in private industry, entrepreneurs, decision makers from government agencies, and consumers to increase adoption of alternative ionizing technologies.