1. Introduction
Irradiation, “a safe, healthy, and clean technology,” is a non-chemical food processing and preservation method [
1] (p. 91) developed more than 100 years ago [
2]. During the energy-efficient irradiation process, ionizing radiation beams (i.e., gamma rays, electron beams, X-rays) are exposed to and sterilize food before it is packaged [
1,
3]. As a result, the radiation beams “eliminate pathogenic microorganisms, insects, fungi, and pests” [
1] (p. 91). Thus, two primary advantages to irradiation exist: increased food safety and food preservation (i.e., shelf life) [
1,
4]. Irradiating food can reduce consumers’ risk of contracting foodborne diseases and reduce food loss due to spoilage or bacterial/parasitic contamination [
1].
Food irradiation was first approved by the U.S. Food and Drug Administration (FDA) to treat foods in 1963 [
5]. However, the FDA did not give “permission for the expanded use of irradiation in the U.S. food supply” until 1987 [
2]. The FDA approved a variety of foods for irradiation, including beef, pork, poultry, crustaceans (e.g., lobster, shrimp, crab), fresh fruits and vegetables, seeds (e.g., alfalfa), eggs, shellfish (e.g., oysters, clams, mussels, scallops), spices, and seasonings [
6]. To this end, about 97 million pounds of food consumed annually in the U.S. is irradiated [
7]. Of this, between 15 and 18 million pounds of irradiated food marketed in the U.S. annually is ground beef and poultry [
8]. Although many grocery stores in Midwestern states sell these products, nationwide availability is still very limited [
7,
9].
Even though food irradiation is deemed safe and endorsed by health-related organizations worldwide, consumers are still reluctant to accept the technology [
10,
11]. As a result, food irradiation has failed to achieve widespread adoption [
12]. The reason consumers’ acceptance of food irradiation and its adoption is so important is because the technology has significant implications for strengthening the food supply [
13]. Irradiation can increase the safety of the food supply by decreasing the prevalence of foodborne disease—a leading cause of disease and mortality across the globe—and also help secure the global food supply by preserving food [
13,
14]. Liu et al. [
15] found approximately one-third of food produced is thrown out or spoiled prior to human consumption. Such post-harvest losses are the leading causes of hunger and malnutrition [
14]. Treating food with irradiation can increase the shelf life of food, sometimes by twofold, thereby increasing food availability [
13].
Still, food irradiation has a bad reputation. Like consumers do with other food and agricultural technologies, they tend to evaluate the risks of irradiation differently from experts [
16]. Risks that consumers commonly associate with food irradiation involve safety, health, and the environment. Consumers generally believe food irradiation is a dangerous, nuclear technology that modifies food properties and contaminates food, making it unsafe to eat [
16]. Much of the fear stems from the word ‘irradiation’ itself because consumers associate it with radiotherapy and radiation, both of which are closely associated with cancer [
17]. The belief also exists that irradiation facilities create hazardous environments for workers [
18,
19]. In addition, many consumers believe the irradiation process decreases the nutritional value of food and negatively affects its color, taste, smell, and texture, even though such effects are minimal [
20,
21]. Some also fear that radiation escapes from irradiation facilities and pollutes the environment [
18,
19].
Irradiated foods are also widely unaccepted because the technology was ineffectively diffused into society [
11] and because information from food processors about food irradiation has often been communicated poorly [
16]. Many scholars have called for better public education and communication about the benefits of food irradiation [
22,
23] to increase consumers’ acceptance. Due to the ineffectiveness of diffusion and communication efforts, Sapp and Downing-Matibag [
11] suggested scholars broaden their theoretical perspective and not simply examine consumer acceptance of food irradiation as a function of perceived risk. A broader empirical perspective may reveal better ways to communicate and educate consumers about food irradiation.
Thus, the purpose of the study described herein was to determine how key factors explain consumers’ behavioral intentions toward irradiated ground beef, specifically, because ground beef is one of the most common U.S. household food products. We achieved the study’s purpose by reviewing the literature to identify key factors that have been found to, or are expected to, influence consumers’ acceptance of food irradiation. We integrated the identified factors to develop a comprehensive theoretical model and evaluated the proposed model using structural equation modeling. Finally, we discussed potential communication strategies focusing on the factors we identified as most significant.
5. Discussion
Teisl et al. [
29] found U.S. consumers had negative attitudes toward food irradiation—a finding we confirmed in our study. These results, specific to U.S. consumers, are contrary to those of [
67], who found Malaysian consumers had positive attitudes toward food irradiation, suggesting such attitudes vary by nationality. In addition, participants’ objective knowledge about food irradiation was low. These results are consistent with results from previous studies that also reported low knowledge levels among consumers, e.g., [
16,
18,
24,
25,
26,
27,
28]. Therefore, it is reasonable to assume that despite food irradiation having been used in the agri-food sector for 60 years, communication efforts to increase consumers’ knowledge of the technology have been unsuccessful.
The theoretical model explained most of the variance in consumers’ attitudes toward food irradiation and behavioral intentions toward irradiated ground beef. Attitude [
40,
60,
63] played the most critical role in consumers’ behavioral intentions toward irradiated ground beef, which was followed by subjective social norm [
60,
63,
64]. Attitude also mediated the effect of subjective social norm [
60,
63,
64,
66], perceived benefit [
23,
24], perceived risk [
23,
24], objective knowledge [
28,
30,
40], and food technology neophobia [
44,
49,
50] on behavioral intention.
These results are like those of [
63] who found that attitude and subjective social norm directly influenced consumers’ intent to accept and consume irradiated foods. However, they are unlike those of [
63,
64,
65], as they analyzed data from 225 Minnesotans about purchase intentions toward irradiated beef patties and did not find a significant relationship between subjective norms and intentions to consume irradiated foods. It is possible that the importance of subjective social norms is increasing with time and playing a larger role in consumers’ decision-making processes when it comes to irradiated foods. Therefore, subjective social norm should be included as a key variable when investigating consumers’ behavioral intentions toward irradiated foods and when marketing irradiated foods to consumers.
To improve subjective social norms, food manufacturers, or communications and marketing specialists working for these companies, should consider designing visual aids that promote irradiated ground beef by emphasizing healthy families and social environments [
66]. Doing so may improve subjective social norms by helping consumers envision people like them consuming such foods and, as a result, become more accepting of them [
66]. Another science communication strategy that may improve subjective social norms is for communications and marketing specialists working for food manufacturers to develop messages from which the information source is another consumer. In other words, the message, whether it be delivered visually or in writing, should be delivered by a consumer. That way, consumers who receive and process the message may feel as though someone similar to them is accepting of these foods.
The effectiveness of these marketing strategies could be evaluated using in-person experimental research. For example, using a post-test-only control group research design, consumers in the treatment group could be exposed to an in-store display promoting irradiated ground beef that depicts a healthy family or a consumer who reflects the target audience in the respective area. Consumers in the control group (or groups) could be exposed to the same display without the image or the same display with a different image—perhaps one with ground beef or cattle. After consumers examine the display, they could respond to a post-test survey that seeks to understand their subjective social norms, attitudes, and intent to purchase the product. It is possible that different grocery stores in the same area and with similar customer bases (i.e., demographics, psychographics) could be used to recruit participants for the control and treatment groups.
As far as we know, our study is the first to provide evidence demonstrating the negative effect of food technology neophobia on consumers’ acceptance of irradiated food, despite other scholars discussing the relationship and presuming one exists, e.g., [
44,
48,
49]. Therefore, we confirmed food technology neophobia is an important psychological factor researchers and practitioners must consider when attempting to understand, and change, consumers’ behaviors toward irradiated foods. Based on the food technology neophobia measurement used, consumers’ belief that new food technologies are unnecessary, specifically, had a negative effect on their behavioral intentions toward irradiated ground beef.
Our results suggest that the goal of science communication about food irradiation should be to increase consumers’ attitudes positively, which is best achieved by aiming to improve subjective social norms, increase perceived benefits, and decrease perceived risks [
23,
24]. Future research is needed to determine, more specifically, what those perceived risks are that most influence consumers’ decision making about irradiated foods (e.g., that they are radioactive) [
1,
9,
11]. Although objective knowledge significantly influenced consumers’ attitudes toward food irradiation [
29,
30], its total effect was small. Thus, the goal of science communication efforts should not necessarily be to increase consumers’ knowledge of the technology because we found other psychological factors were more important.
One strategy that may increase perceived benefits and decrease perceived risks is communicating with consumers at the point-of-purchase using voluntary labels on food product packaging. Such messages should include information about the benefits of food irradiation, such as that it can increase the safety of consuming ground beef, that it preserves the nutrients in ground beef, and that it is an ecologically friendly process [
99]. These particular messages may also correct common misperceptions of the technology [
1,
9,
11,
27,
57]. The placement of voluntary labels that provide technology-related benefits should be considered (i.e., front of food package, back of food package), as should the context in which they are read (i.e., at the grocery store, at home), because consumers may respond differently under the various circumstances based on their psychological characteristics (e.g., subjective knowledge about nutrition, perceived importance of information, perceived credibility of information) [
100]. Like the aforementioned experimental research study that could be conducted to determine if in-store displays depicting families and/or consumers improve consumers’ subjective social norms, a similar research design could be used to determine if voluntary labels including information about the benefits of food irradiation increase consumers’ perceived benefits and decrease their perceived risks.
Also important is the null effect of environmental concern on consumers’ attitudes toward food irradiation. Although consumers fear that the process of food irradiation pollutes the environment [
18,
19,
39], their attitudes toward the technology are not affected by general concern for the environment. This could be because food irradiation is a processing method rather than a production method. Our study was the first to investigate environmental concern in the context of a food processing technology, but previous studies investigating environmental concern in the context of agricultural production technologies (i.e., genetic engineering) found it to influence consumers’ attitudes negatively, e.g., [
18,
34,
35,
36,
37,
38]. Future research should focus on determining if environmental concern does indeed affect consumers’ attitudes differently depending on when the technology is applied in the food supply chain.
Health consciousness also had a null effect on consumers’ attitudes toward food irradiation. Although consumers fear that irradiated foods might negatively impact their health [
11,
16,
27], health consciousness did not affect acceptance. This finding came as a surprise because health-conscious consumers tend to prefer foods that they believe are natural and not processed [
51]—two qualities they do not associate with irradiated foods [
16,
17,
20,
21]. Therefore, while communicating about the healthfulness and safety of irradiated foods is important to decrease perceived health risks, emphasizing other health-related information during communication is not necessary based on our results.
We recommend scholars evaluate the model to determine how well it explains consumers’ behavioral intentions toward other irradiated foods. Do the effects of predictor variables differ significantly when irradiation is used to treat fresh meat products other than ground beef? Do the effects of predictor variables differ significantly when irradiation is used to treat products of animal origin versus products of plant origin? Answers to these questions would help determine if the applicability of the model expands beyond the context of the current study. They would also help determine if the communication needs of consumers are different and, therefore, if marketing and communicating about irradiated foods needs to be different based on the product or if a one-size-fits-all approach would be effective.
A similar research recommendation is for scholars to evaluate the model to determine how well it explains consumers’ behavioral intentions toward foods produced or processed using other novel agri-food technologies, such as gene editing and nanotechnology. Such studies would respond to [
18], who highlighted the need for using large sets of predictors to explain consumers’ acceptance of different agri-food technologies. Results from studies using the same model and measures would help us critically and accurately evaluate differences in consumers’ responses to agri-food technologies and understand how to leverage those differences, should they exist, when developing marketing and communication strategies. Evaluating the model further to determine its applicability in these various contexts would best be achieved using cross-sectional surveys with large, nationally representative consumer samples.