CONSUMER AWARENESS ABOUT IRRADIATED FOOD: A SYSTEMATIC REVIEW.

* Tiago Rusin 1,2 , Wilma Maria Coelho Araújo 1 , Ernandes Rodrigues de Alencar 3 , Lívia de Lacerda de Oliveira Pineli 1 and Helio de Carvalho Vital 4,5 . 1. College of Health Sciences, University of Brasília, Campus Darcy Ribeiro, Asa Norte, Brasília, 70910-900, Brazil. 2. Ministry of the Environment, Esplanada dos Ministérios, Bloco B, Brasília, 70068-900, Brazil. 3. College of Agronomy and Veterinary Medicine, University of Brasília, Campus Darcy Ribeiro, Asa Norte, Brasília, 70910-900, Brazil. 4. Technology Center of the Brazilian Army (CTEx), Av. das Américas, 28705 Barra Guaratiba, Rio de Janeiro, RJ, 23020-470, Brazil. 5. Department of Nuclear Engineering, Military Engineering Institute (IME), Praça Gen. Tibúrcio, 80, Rio de Janeiro, RJ, 22290-270, Brazil. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


ISSN: 2320-5407
Int. J. Adv. Res. 6(3), 415-486 419 have been used to determine whether the statistical techniques selected are indeed appropriate for the task of efficiently retrieving the information in order to interpret and evaluate the quality of the data. Thus, based on such criteria, a scoring method was summarized in Table 2.
Two reviewers (TR and ERA) performed RB analysis of the studies. Reviewers resolved disagreements by discussion and the third reviewer (LLOP) adjudicated unresolved disagreements. Each criterion received scores between 0 and 100 or unclear (U) in the evaluation of the studies. In the calculation of the RB, the unclear (U) cases were not included and an arithmetic mean was calculated. According to the value of frequency, RB can be estimated. The criterion for defining high, medium or low RB was based on the article by Gadioli, et al. (2017). When the frequency was higher than 70%, the RB was considered to be low (L), when the frequency was between 50 and 69%, it was considered moderate (M) and when the frequency was lower than 50%, the RB was considered to be high (H).

Results:-
Selection of relevant studies: Table 3 presents eligible studies, their characteristics and data gathered from the survey, such as consumption, comprehension and willingness to buy irradiated food. Initially, 1,192 studies were identified in the electronic databases and 1,132 findings remained after duplications were discarded. A comprehensive evaluation of the abstracts was then performed in phase 1 and 61 articles were deemed potentially appropriate, according to the inclusion and exclusion criteria. They were then selected for assessment in phase 2. Moreover, 266 articles were found in an additional search through Google Scholar (n= 30) and ProQuest (n= 236) and only three of them were considered to meet the inclusion criteria. Out of the 64 studies included, 20 were subsequently excluded: Adams (2000), Ahmed (1993), Bruhn (1995a), Bruhn (1995b), Bruhn (1998), Cottee et al. (1995), Derr et al. (1995), Henson (1995), Hunter (2000), Ihsanullah and Rashid (2017), Loaharanu (1990), Marcotte & Kunstadt (1993), for being review articles; Beaulnes (1988), for being case report; Bruhn (1999), Eustice & Bruhn (2013), for being chapters of books; Coates (1990), Engel et al. (1990), Henon (1995), for personal opinion; Goss et al. (1995), for being a conference abstract; Weaver & Marcotte (1988), for not being related to consumer knowledge on irradiated food. Other 22 studies, extracted from reference lists, were added. Thus in the end, 66 studies were retained for this systematic review (Figure 1).
The analytical methods used for data collection included questionnaire (62.4%), interviews (27.5%), surveys (7.2%) and/or focus group sessions (2.9%) all of them including objective questions, except for the research of Behrens et al. (2009) where open-ended questions were answered as part of a qualitative study. Most of the studies comprised statistical treatments of descriptive analyzes (54 references) and/or regression analysis (30), significance (13), reliability (7), factor analysis (5), variance (5) and correlations (3).

Awareness about Food Irradiation: United States of America:
The first studies that evaluated consumers' knowledge about irradiated food date as far back as 1983. The level of knowledge on irradiated food is constantly changing worldwide. In addition, it has been found in this work that 420 American consumers usually exhibit an intermediate level of knowledge on the subject (Frenzen et al., 2001). The trend of the data indicates that the American population has increased their awareness of irradiated food over the years. Further details of the surveys can be better seen in Table 3.
Comprehensive studies such as those by Bord & Connor (1989), Schutz et al. (1989), Malone (1990), Frenzen et al. (2001), Aiew et al. (2003) and Feng et al. (2016) show the trend of increase in awareness over the years, influenced by the greater ease of access to information on the subject.
It is possible to find more specific studies, which corroborate with the omnibus findings. In California, an increase in awareness about food irradiation can be seen through studies by Bruhn & Noell (1987) and Bhumiratana et al. (2007), which corroborate the findings for Wisconsin (Jarosz et al., 1989), Texas (Schutz & Cardello, 1997), Kansas (Fox & Olson, 1998) and Minneapolis (Vickers & Wang, 2002).
The studies conducted in Atlanta  and Illinois (Spaulding et al., 2007) are in agreement with the earliest study found in the systematic review, Titlebaum et al. (1983), who found that the initial reaction to the irradiation process was unanimously negative. They found that the participants were concerned about the safety of the process and about the chance that any residual radioactivity might remain in the products.
Research shows that educational actions favorable to irradiated food positively influence the change in consumer attitudes, while unfavorable information leads to negative attitudes by consumers. Rodriguez (2007) identified that the respondents who had received the unfavorable information packet were less supportive of food irradiation than those who had not received it. On the other hand, Aiew et al. (2003) found that, after the presentation of positive information about food irradiation, most respondents were willing to buy irradiated ground beef. Titlebaum et al. (1983), evaluating the acceptance of irradiated food, showed that consumers initially responded negatively to the idea of irradiated food. However, the response would become more encouraging after consumers being properly provided with adequate information about the process. Thus, after some time inspecting and trying irradiated food, in addition to being exposed to straightforward labels on the irradiated food, a significant fraction of consumers would even decide to purchase and consume irradiated food. Bruhn et al. (1986a) and Bruhn et al. (1986b) found similar results among conventional consumers regarding their change of attitude towards irradiated food. An educational program, which would address and explain the irradiation technique to consumers could impact positively consumer response, leading to an increase in the acceptance of irradiated food among conventional consumers, although it may not have an effect on those already opposed to the process (Bruhn et al., 1986a). According to Bruhn et al. (1986b), conventional consumer attitudes toward food irradiation can be positively influenced by an educational effort.
Knowledge about the process as well as keeping a positive attitude toward food irradiation increased as a result of participation in a teleconference on the subject (Johnson, 1990). Hashim et al. (1995), researching the consumer purchase behavior of irradiated beef product, showed that the number of participants who purchased irradiated poultry products increased after the educational program. Similar results were found by Qixun et al. (1993) According to Terry & Tabor (1988), the use of the term -irradiated‖ causes a substantial decrease in consumer preference for irradiated products. Currently more information is still needed to prevent the negative effect of not providing enough information to consumers (Hashim et al., 2001). Thompson & Knight (2006) identified that most participants of their interview had not been frequently advised on the food irradiation process. According to Cardello et al. (2007), Teisl et al. (2009) and Mehmetoglu (2007), the majority of consumers naturally present negative attitudes towards irradiated food. Consumer behavior towards irradiated food certainly depends on the levels of awareness and knowledge on the benefits or risks associated to the technology. Fox et al. (2002) and Hayes et al. (2002), respectively, conducted market trials of irradiated chicken and performed an investigation to evaluate how information affects the demand for food irradiation and, based on the results, they concluded that when both positive and negative information about irradiated food were simultaneously provided, a 421 negative response prevailed in consumers' decisions. A campaign in favor of irradiation significantly contributes to increase the demand of irradiated products and increases willingness to pay, while negative information causes the opposite effect. Moreover, when subjects were given both the pro-and the anti-irradiation descriptions, the negative description dominated and willingness to pay subsided .
As Hayes et al. (2002) were studying the effect of simultaneously providing favorable and unfavorable descriptions about the effects of irradiation, they noticed that such strategy had essentially the same effect as that of providing only the unfavorable description. They found clear evidence that the content of information given to consumers directly influenced their response and attitude (positive, negative or neutral) towards the subject.
In his research, Wie et al. (1998) claimed that most respondents agreed that they wanted to know more about irradiated food. Bruhn & Schutz (1999) found that consumers need information on protective technologies such as food irradiation. Deliza et al. (2010) concluded that consumer education regarding the technology is a key factor to its acceptance.
The research by Lusk et al. (1999) demonstrated that women were more concerned about irradiated products than men and also that the more anxious a person is, the more concerned he will be about food irradiation. According to Cardello (2003), concern levels were highly susceptible to the influence of positive marketing. Hoefer et al. (2006) found that there is a general lack of awareness among consumers regarding the availability of irradiated meat leading to misunderstandings about the safety of irradiated meat (Table 3).

Other Countries:
Countries like England (Robson & Payne, 1988), Turkey (Gunes &Tekin, 2006 andMehmetoglu, 2007), Japan (Furuta et al., 1998;Furuta et al., 2000;Inoue, 2000 andFuruta, 2004), China (Qixun et al., 1993)  In addition, it is important to consider that the consumer does not always read and/or understand the information described on the labels of processed food before or after the purchase. Labeling is an important strategy not only from the point of view of nutritional quality, but it also provides information on the application of new technologies in the processing of that food. Therefore, labeling of irradiated food is of paramount importance for consumers to meet their expectations and preferences during purchases. There is a great gap in the identification of such food and the symbol of Radura is often unknown to the consumer (Robson & Payne, 1988;Terry & Tabor, 1988;Ornellas et al., 2006;Junqueira-Gonçalves et al., 2011, Nayga et. al., 2005and Spaulding et al., 2007. It is possible to understand the purchase of food as a sphere in which the relationship between the understanding of the technical information described in the labels and the behavior of the consumer with regard to the decision of whether or not to purchase these products is clearly identifiable. It is based on the information of the labels that the consumer exercises his right of choice and the principles of consumer protection guaranteed by the regulatory systems (Einsiedel, 2002 andQin &Brown, 2006).
In general, respondents view labeling as necessary information to ensure consumer choice (Crowley et al., 2002). In a study by Lima Filho et al. (2015), consumers identified as the ideal label for irradiated strawberries, which provided the following information: -Food treated by ionization process‖ or -Food treated by irradiation process‖, -To ensure freshness and quality for a longer time‖ and the presence of the Radura symbol.
The willingness to buy irradiated food encounters great resistance on the part of consumers, often due to the lack of knowledge about the process and misconceptions. In the last years, developed countries, such as the United States  Table 3 presents a detailed evaluation of each RB criterion for each study. Low RB criteria has been achieved by only 12.1% (8) of the eligible studies, whereas, 42.4% (28) have been classified as moderate RB and 45.5% (30) as high RB. Few studies (24.2%; N = 16) presented representativeness of the population they were meant to analyze; in addition, 84.9% (N = 56) of the articles clearly showed that their sampling was random, whereas 12.1% (N = 8) were not random and for 3% (N = 2) were not clear with regard to their objective.

Risk of Bias (RB):
Most articles (87.9%; N = 58) presented well-defined criteria for inclusion and/or exclusion in the sample of interest, whereas in 9.1% (N = 6) of them the criterion was not clearly defined, causing doubts to the reviewers and in 3% (N = 2) of the cases inclusion criteria were unclear (Table 3).
Only one research, of qualitative nature, did not use statistical treatment (Behrens et al., 2009). Fifty-four studies used the descriptive analysis; thirty studies adopted regression analysis; thirteen applied tests of significance; seven included reliability tests; five performed factor analysis; five relied on variance analysis and three ran correlations tests, which have often been combined for better interpretation of the results.  (Table 3).
It must be stressed that it is important to assess the potential RB involved in conclusions of studies belonging to a systematic review and how strong evidence based on them most be considered. RB assessment of individual studies is a step for determining the strength of a body of evidence (Viswanathan et al., 2012). In the elaboration of this work in particular, the RB assessment was not a straightforward task due to the high heterogeneity of the methodological approaches employed in this research domain and because of the lack of standardized quality assessment tools for studies belonging to the social science field (Cox et al., 2015).   (TITLE-ABS-KEY("food irradiation") AND TITLE-ABS-KEY(knowledge) OR TITLE-ABS-KEY(attitude) OR TITLE-ABS-KEY(perception) OR TITLE-ABS-KEY(awareness) AND  TITLE- ("food irradiation" (knowledge OR attitude OR perception OR awareness) consumer (survey OR questionnaire OR interview)) INIS 761 artigos "food irradiation" AND (knowledge OR attitude OR perception OR awareness) AND consumer AND (survey OR questionnaire OR interview)  Participants considered information on the sterilizing action of irradiation of food, its impact on human health, the increase in the shelf life of the products and the labeling information to be of fundamental importance for the purchase and consumption decision on irradiated food. They also reported a pronounced sensitivity to the term "radiation" by considering accidents with nuclear reactors. 98% of questionnaire respondents are interested in food products that stay fresher longer. The spices received the lowest percentage of consumer interest (38%). The participants were wary about the safety of the process, whether there would be any residual radioactivity in the products, and whether the appearance and the taste of the products would be changed. The techniques used to inform the consumer about food irradiation, leaflet and posters, were effective in generating changes in the consumer's attitude towards the purchase and consumption of food irradiation. Consumers appeared to be more concerned with the use of "chemicals" in food than with irradiation itself, although they were concerned about the effects after irradiation. Resistance to the consumption of irradiated food was greater among ecologically sensitive consumers and among the younger ones.
Although there were concerns about the safety of irradiated food, consumers were willing to buy the products. Alternative consumers had a higher level of concern than conventional consumers. Initially about 53% of both conventional and alternative consumers were undecided about the safety of irradiation. Following a discussion, undecided conventional consumers shifted primarily to "minor concern" (46%) with an equal number (15%) to "major" and "no concern". Alternative consumers shifted primarily to "major concern" (80%). For all subjects, 73% who considered irradiation a major concern initially, maintained that attitude. 20%, however, shifted from a major to a minor concern. Half of those who initially felt a minor concern maintained that stance. Conventional consumers' attitudes toward food irradiation can be positively influenced by an educational effort. More people had heard of irradiation in the Irvine market (58%,) than the Anaheim location (47%). 66% of the participants from Anaheim and 80%, from Irvine said they would buy a picked ripe/irradiated papaya in the future. Consumers from the upscale market showed greater acceptance of the irradiated product. Although about 50% of the sample had heard of irradiation, few of the people were aware that the process was FDA approved. Almost half of respondents (41%) were aware of food irradiation, with TV being their major source of information (47%). Considering the process of safe irradiation, 24% of the interviewees expressed preference for irradiated food. The majority of the respondents insisted that all irradiated food should be labeled and a large proportion expressed a preference for a picture label, although 49% said that Radura's emblem did not suggest anything to them. In the end, 27% of the public would buy irradiated food. The most of the respondents did not associate the identified symbol with the process of irradiation, only 2.8% knew what the irradiation symbol truly represents. At equal prices, 33% of the food buyers preferred the products with the irradiation symbol, 12% preferred the product without the Radura symbol, and 55% were indifferent. The use of the term -irradiated‖ causes a substantial decrease in consumer preference for irradiated produce, however the presentation of additional information to the respondents resulted in a dramatic increase in both the acceptance of irradiation and the willingness to pay. Questionnaire; focus-group discussion; General food; Descriptive statistics and correlation analysis.

Main
Results: The number of willing to try irradiated food increases significantly after the presentation of information about food irradiation. The intense majorities neither want nor oppose irradiated food. Only 32% of sample report having heard anything about the topic prior to participation in this study. The women of sample were quite uninformed about the food irradiation issue. The extent to which the public ultimately accepts or rejects irradiated food may well be predicated on the presence or absence of information about the topic and the type of information that reaches the public. More than half of the respondents (57%) had not heard of food irradiation. 60% of all respondents were unfamiliar with the process of irradiating food. Without the information on food irradiation, more than half of the respondents were undecided about the possibility of an irradiated seafood product being served in a higher restaurant. Respondents' confidence in the approval of food irradiation by the American government showed great potential for positive change in the position of respondents. Food and public health professionals interested in food irradiation need to take an active role in communicating about the process with the public. More than half of the respondents (59.7%) had heard about food irradiation, while 37.5% had never heard of it and 2.8% did not know it. A quarter of the population shows major concern with regard to irradiation, but better educated respondents were less likely to feel FDA approval would increase their concern. About half of the respondents indicated that it would be likely or very likely to purchase irradiated food in the marketplace. The "irradiated to control microorganisms" label results in the most positive connotation. Respondents had a good acceptance for irradiated poultry and pork. Almost half of the respondents (43%) opted for irradiated fruits over non irradiated ones. More than half of the respondents (57.9%) reported that they had consumed irradiated food, but it is likely that some of the respondents confused the irradiated products with other processing methods, as almost four-fifths of respondents did not know the definition of "radurization" and almost half responded 433 incorrectly to the question about the availability of shelf-stable irradiated food in the United States. The population generally had a positive attitude toward the irradiation of food. The home economists lacked knowledge about the irradiation process, although they had a positive attitude toward it and desired to learn more about it. Knowledge of and a positive attitude toward food irradiation increased as a result of participation in a teleconference. Interview (telephone interview); Objective; Fresh food products; Descriptive statistics, chi-square analysis and Probit analysis.

Main
Results: A quarter of the respondents (25.2%) had heard about the irradiation process, demonstrating that consumer knowledge about irradiation is scanty. About 36% were willing to purchase such products, a high percentage of those not willing to purchase have not heard of irradiation, 77.1%. There has been an increase in the number of consumers willing to pay more for irradiated food when informed of the reduction of foodborne disease.

Main
Results: Most respondents (82%) have already heard of the treatment of food with ionizing radiations. With regard to the contaminated food by radionuclides, 75% of consumers distinguished it from irradiated food. Irradiated food was more acceptable (35%) than chemically-treated food (13%). Providing some information to consumers regarding the benefits which could be achieved through irradiation resulted in a more positive response (60%) with regard to potential purchase of irradiated anchovies. About 71% of respondents implied that insufficient public information and incorrect understanding of food irradiation were major reasons for retardation of commercial utilization of this technology. About 67% of consumers heard about food irradiation. After information on irradiated food, 72% of respondents believed that irradiated food were better than non-irradiated food. Approximately 72% of persons and 67% of families were willing to buy irradiated seasonings. Most consumers hoped that the food irradiation technology should be applied to markets as soon as possible so that they could buy more food in markets, however, a few consumers did not believe that the Irradiated food are safe. The number of participants who purchased irradiated poultry products after an educational program increased by more than 20%. Using a label or poster did not increase the number of participants who bought irradiated poultry products. Most of the participants who evaluated the irradiated chicken during the domestic use test were satisfied with it. About 84% of the participants would like all chicken served in restaurants or fast food places to be irradiated. Almost half of respondents (47%) were willing to pay more for irradiated chicken. About 72% of consumers are aware of irradiation and, among these, 87.5% indicated that they have heard about irradiation but do not really know that much about it. The low level of real information that consumers have about food irradiation was observed, because 33% of consumers believe that irradiated food is radioactive. The label of irradiated food was important to 81% of consumers. The international logo and the statements were considered by half of the respondents to be insufficient to inform consumers that the food is irradiated. After being informed about the importance of irradiation, 50% of respondents said they would prefer to buy irradiated meat or poultry. Nearly 38-42% of the consumers who would purchase irradiated food were willing to pay 1-5% more, and over 10% would pay up to 10% more than they now pay. Half of respondents would be willing to pay extra for poultry-meat which had been irradiated. Only 6% would buy irradiated poultry-meat if there was no additional cost. About 34% expressed concern about safety of poultry-meat processed by irradiation. Nearly 17% thought irradiation to be unnecessary, this suggest that food irradiation has still not gained full public acceptance. Interview (computer-assisted telephone interviews); Objective; General food; Logit and probit analysis.

Main
Results: Only 16% of the respondents considered the use of irradiation at approved levels to be safe. The most important economic factors that affect the probability that a main meal planner will consider irradiated food to be safe are: gender, urbanization, income, education, and to some extent race and age. More than 57% of the subjects stated they were seriously concerned about the irradiation of food. There is a willingness to pay for elimination of disease-causing bacteria through irradiation for the majority of respondents, the participants were Willing To Pay (WTP) an average of $0.71 for the right to exchange a typical meat sandwich for a sandwich irradiated to eliminate the potential risk of foodborne bacteria. There was a positive relationship between WTP and the perceived risk of foodborne disease, and a negative relationship between WTP and years of education. There is a relatively low level of awareness of irradiation as a preservation food process among military personnel, only 16.9% of respondents heard of irradiation as a food preservation method. The willingness to consume irradiated food to both military dining facilities and field situations is low prior to information presentation, as is willingness to consume specific food classes that have been irradiated. However, the results on the effect of the various treatment conditions revealed a strong positive effect for one treatment, the Purdue University video, and a smaller effect for the 20/20 video. It does appear that there is more willingness to consume irradiated food in the field than in the military dining facility, which may indicate that of irradiated food the introduction to the military may occur more easily with field rations than with dining hall food. About 81% of respondents to the mail survey indicated that they would choose the irradiated poultry product if it were available at the same price as non-irradiated. Just over half of respondents (55%) of respondents who indicated they had heard of food irradiation prior to the survey, 82.5% chose irradiated and of those who had not heard of irradiation, 78.5% chose irradiated. In retail trials, when irradiated and nonirradiated chicken were equally priced, the irradiated product accounted for 43% of total sales, significantly lower than the mail survey result of 81%. Results from the market experiments suggest that shoppers' unawareness of the benefits of food irradiation was a major factor accounting for the differences between the mail survey and the retail trials. 80% of participants purchased irradiated chicken in the market experiment. The ratio of visitors who had heard something about radiation increased with increasing age. The ratio reached 94.6% at the ages of 13-15 years. After viewing an exhibition, kids visitors answered "understand well" (22.6%) and "understand a little" (47.5%) about radiation. Participants found that "Roentgen" (48.5%) and "atomic power generation" (29.5%) were the closest words associated with "radiation". After viewing the display and description of irradiated potatoes, 14.5% indicated that they wanted to taste the irradiated potatoes. About 85% of respondents who knew potato irradiation indicated that they also knew the existence of natural radiations. Food irradiated to reduce spoilage was considered a major concern by 33% of respondents. Only 36% recognized that irradiation of meat or poultry destroys bacteria that causes foodborne illness. About 33% knew irradiated food are considered safe by health and safety organizations. Consumers considered university scientists and health professionals to be a more reliable source of food safety information than family or friends. Consumers need information on protective technologies such as food irradiation. The concern of food irradiation is less than that of other food safety concerns and other bacterial prevention methods such as preservatives and chemicals. The average concern for irradiation was 3.228 on a scale of 1 to 5, which means that consumers on average still displayed somewhat of a concern for irradiation. The information about the irradiation process decreases the concern with food irradiation. The more beef a person consumes, the less concerned they are with irradiation. The households who are likely to purchase irradiated beef packages are more likely to store it for a longer period before cooking or freezing it. Of those who chose all irradiated packages of the ground form of beef, 62.07% stored for two or more days before cooking. The respondents who stored ground beef for several days before cooking were likely to choose irradiated packages. Every additional day of refrigeration before cooking or freezing increased the selection of irradiated ground beef by 0. 25  The percentage of consumers who purchased all irradiated packages based on the poster information was about 15%. The poster was effective in causing a change in beef purchase behavior. Nearly 28% of the participants who purchased mixed packages of ground beef exclusively during the first shopping trip purchased all irradiated samples during the second shopping trip. The store-level information concerning the benefits of irradiation, made available at the point-of-purchase, was sufficient to motivate some of the consumers to shift towards irradiated products and discouraged some consumers from purchasing irradiated beef. Providing positive information about the irradiated product increased its value, shifting out the demand curve, while negative information about the product has decreased its value. A favorable description of irradiation increased willingness-to-pay, and an unfavorable description decreased willingness-to-pay. When subjects were given both the pro-and anti-irradiation descriptions, the negative description dominated and willingness-to-pay decreased. The combined positive and negative descriptions resulted in 56,3% subjects downgrading their safety assessment for irradiated pork. When the same favorable and unfavorable descriptions are presented simultaneously, the net impact is a significant reduction in bids for the irradiated product, with the median bid falling to zero. The favorable information reinforces the perception that the irradiated product is safe. In the negative treatment, participants downgrade their safety assessments. In the both treatment, the net effect is a downgrading in the relative safety assessment. The effect of providing both the favorable and unfavorable descriptions had essentially the same effect as that of providing only the unfavorable description. Irradiation has raised concern among more than 65% of the consumer test population. The term ‗ionizing energy' elicited somewhat lower levels of concern than the term ‗irradiation'. The willingness to try food processed by one novel or potentially ‗risky' technology is associated with a lower level of concern about the risks associated with a broad range of novel food processing technologies. The concern levels had the greatest potential to be positively influenced by the information treatments. Almost 70% of the participants indicate an improvement of the image of ‗‗radiation'' and 40% point out that the display of the irradiated products is the cause of the improvement. Only less than 5% indicated '' Irradiation '' as being one of the major concerns about food safety issues for respondents. The ratio of the respondents still persisting in the idea that irradiated potatoes were hazardous remained only 5 About 58% of the respondents are willing to pay a premium for irradiated beef. Nearly 68.3% of the respondents who would consider a food irradiation label as a symbol of warning are not willing to pay a premium. Approximately 45.6% of the total sample indicated that they trust the technology and they are willing to pay a price premium for irradiated beef. Those who trust the irradiation technology are more likely to pay a premium of between 5 and 25 cents per pound for irradiated beef. After a video exhibition, the students' perception about food irradiation process switched from normal to comfortable. In the tasting test, it was verified a good acceptance of irradiated fruits and honey. Although 83% of the respondents had already heard about food irradiation, only 17% had seen/known the radura symbol that showed the low level of dissemination and information on food irradiation process. Interview (face-to-face interviews); Objective; Beef products; Descriptive statistics and Probit analysis.

Main
Results: About 67.1% considered the radura symbol an assurance of quality and were more inclined to purchase irradiated food. After the brief presentation of nature and benefits of food irradiation, the proportion of respondents willing to buy irradiated food increased from 50% to 89%. The information about the nature and benefits of food irradiation has a positive effect on perceived segment shifts and willingness to buy. Respondents who have a perceived knowledge of food irradiation are 17.6% more likely to buy irradiated ground beef than those who do not, prior to the presentations. Only 29% of respondents indicated that they had heard food irradiation before. Only 11% of respondents reported that food irradiation is safe. About 62% of consumers indicated that they would buy irradiated food. Near 64% of the respondents who were uncertain about safety of irradiated food indicated that they would buy irradiated food upon hearing the benefit statement. About 23% of respondents indicated that they would pay 5% premium price for irradiated food. About 59.6% did not know that irradiation is a method of food preservation, and could not answer whether they would consume irradiated products and only 16% believe that irradiated food mean the same as radioactive food. Most respondents (92%) do not know the symbol of irradiation, radura, and 16% would buy food irradiated by the influence of the symbol, even without knowing its meaning, informing that radura transmits confidence, security and quality, by the image of the flower in green coloration. Nearly 81% of respondents believe that the label with the radiation symbol and additional information on the label are important. Approximately 89% of respondents would consume irradiated food if they knew that irradiation increases food safety. Evaluati Classificati Most participants did not provide education on food irradiation (53%). Results suggest that educators' beliefs about the safety and their understanding of food irradiation are predictors of the educational outreach they provide about it, indicating the potential value of professional development regarding food irradiation. Perhaps professional development for community nutrition educators, such as FCS county extension agents, might improve not only their beliefs about their understanding of food irradiation and its safety, but also the amount of education they provide on this food safety topic. Although 49% of respondents had heard of food irradiation, most (70%) reported that they had little or no knowledge about the process. After participating in the program, over 80% of respondents agreed with the statement that irradiation is an effective method to destroy harmful bacteria in food and supported the availability of irradiated food at the supermarket. Intent to purchase irradiated meat and fruits increased significantly as a result of participating in the program. About 36% of total respondents specified that they would be willing to pay a 10% premium for irradiated meat. Irradiation presented one of the highest negative utility values for all consumer groups. "Ionizing energy", a synonym for irradiation, was viewed more favorably than the term -irradiation‖ among all respondent groups, although this difference only reached significance among the shopping mall respondents. For all consumer groups tested, the food processes/production methods that were perceived most negatively were genetic modification and irradiation. Georgia consumers had a good chance of buying irradiated poultry (65%) and pork (58%) products. About 77%, considered that irradiation process is somewhat necessary and more than 55% of the respondents indicated they would support the use of food irradiation. The respondents would be willing to pay a higher price for irradiated chicken breast meat for an average of about $1.17/lb. For pork, those respondents would be willing to spend an additional $8. 45  Those who did receive the information packet expressed acceptance of food irradiation nearly at the midpoint of the response scale. Most respondents thought they had control over whether they ate irradiated food. The respondents who received the unfavorable information packet were less favorable about food irradiation. The factor that most influenced opinion change was trust in scientists and in respected health-related organizations. Questionnaire; Objective; Ground beef products, poultry, vegetables and spices; Descriptive statistics, chi-square test, factor analysis, Cronbach's Alpha reliability and logistic regression.

Main
Results: About 64.6% of participants said they had heard of food irradiation before taking the survey and 74.7% said that they would buy irradiated ground beef. Most respondents (88%) said they would be likely to purchase a food item labeled with -Treated by Irradiation‖ or -Treated by Cold Pasteurization‖. Most of the participants reported that they would buy irradiated poultry (72.2%), vegetables (63.3%), and spices (59.5%). Only 20.3% of participants said they would pay additional cost if the shelf life of the product was extended with irradiation. Nearly 38,6% of the participants were concerned that irradiation process would make food radioactive. About 79% of respondents indicated they had never attended a workshop or other educational training on food irradiation. The participants perceived their understanding of food irradiation to be limited. The educators' attitudes regarding the safety of food irradiation were positively correlated with their perceived understanding of food irradiation, knowledge of it, participation in previous food irradiation learning experiences, and their perceived competence to teach about it. Only 29% of respondents had heard or read about irradiation as a method of food preservation. Not considering food science students, only 15% of respondents had read or heard about food irradiation. About 14% of respondents consider that irradiated food are radioactive and 92% of respondents answered that irradiated food should be labeled as such. Only 14% said they would buy irradiated food. The Argentine consumers' initial knowledge about food irradiation was very limited.  Most of the participants stated that they had never heard about food irradiation. The expression food irradiation initially evoked negative feelings among housewife's in both groups, whose primary associations were with nuclear plants, Chernobyl, X-rays and cell destruction. After reading the written information and listening to the explanation about the process, most participants seemed to get a better understanding about irradiation. Participants did not observe significant differences between the irradiated food samples and their nonirradiated in sensory analysis with lettuce salad, roast chicken and mango in slices. Before education about irradiated food, 37.6% of housewives never heard of irradiated food. There have been good changes in understanding about irradiated food before and after education, using different channels of information. The major changes in the intention to buy irradiated food were caused by the video information channel, followed by the book and lecture. Initially, acceptance and trust in proponents were negative, three months later, acceptance still was unfavourable but was no longer significantly lower than the scale mid-point. Exposure to diverse perspectives forced consumers to develop a more moderate stance towards food irradiation and made them less fearful of the technology. The changes in trust and perceived risk significantly affected changes in acceptance. Attitudes toward irradiation are generally negative. Consumers see a positive value of irradiation in that it reduces the danger of bacterial contamination in food, but they are concerned about its effects on nutritional quality. The number of people who consider themselves informed about irradiation is still low. Food irradiation becomes more acceptable as consumers become more informed, principally because their concerns about its effects on the environment and nutrition are eased. About 60% of participants had never heard of food irradiation. The consumers who had some knowledge about food irradiation tended to prefer higher priced nonirradiated products, but rated low priced irradiated papayas similarly to low priced nonirradiated ones. It may be possible to increase purchase probability by providing information about food irradiation. Consumer education regarding the technology is a key factor to its acceptance. Consumers demonstrated differences in willing to pay for irradiated lettuce, depending on the information given at the beginning of the questionnaire. About 51% of subjects declared they would accept paying the random price presented for an irradiated iceberg lettuce. Most respondents considered that the water quality in Mexico City is rather poor and represents health risks, this perception might have had a role in the acceptance of food irradiation as a way of preventing water-borne diseases. About 68% of the total sample size accepted to buy irradiated fresh vegetables if its available in the markets. Acceptance by irradiated food is inversely proportional to the level of education of Egyptian respondents, with the increase of the level of education of the respondents, the level of rejection for irradiated food increases. Acceptance of irradiated food increased with the respondents' age. About 76.5% of interviewed people did not know that irradiation could be used as a method for food preservation and they could not reply on the question whether they would or would not consume irradiated products. Approximately 45.9% expressed their belief that irradiated food means the same as radioactive food. Nearly 55.8% of the consumers affirmed, that they would not buy irradiated food and most (90.7%) claimed that they would become consumers of irradiated food if they knew that ‗‗irradiated'' is not ‗‗radioactive'' and that proper irradiation enhances food safety. Almost all (95.8%) were not familiar with the ‗‗Radura'' symbol. One-third of the preparers were aware that irradiation could be used to reduce harmful bacteria and thereby reduce the risk of foodborne illness. When favorable information was passed, almost half, 48%, said they would be interested in buying irradiated chicken. The optimal package for irradiated strawberries carries the following information according to the RBCA and MCBCA results: -Food treated by ionization process‖ or -Food treated by irradiation process‖, -To ensure freshness and quality for a longer time‖ and the presence of the radura symbol. About 57% of respondents know that food can be irradiated for several purposes, 13% said they had consumed irradiated food and 31% of the respondents stated that they would consume irradiated food. After receiving informational material on Food Irradiation, 44% of the respondents answered that it is a safe technology for food processing. An increase in acceptance by 90% was found after providing informative material. Approximately 42% would consume/purchase ready-to-eat spinach leaves that were subjected to an irradiation treatment. When the frequency was higher than 70% the risk of bias (RB) was considered to be low (L), when the frequency was between 50 and 69% the RB was considered to be moderate (M), and when the frequency was lower than 50% the RB was considered to be high (H).

Discussion:
A systematic literature review technique was used to identify consumer knowledge on food irradiation and the data obtained answered the hypothesis constructed for the development of this study (the "Outcome"). The data obtained in the 66 selected studies showed that: a) must consumers are aware of the benefits of irradiated food; b) in older researches, levels of knowledge and acceptance of irradiated food tended to be lower for both developed and developing countries, but over the years a trend can be noted with developed countries tending to have higher rates 479 of knowledge and acceptance than developing countries; c) favorable or positive information about irradiated food positively influence consumer attitudes, while unfavorable information leads to negative consumer attitudes towards irradiated food.
However, from the methodological point of view, when the criteria for RB assessment are applied, the reproducibility of some studies may be complex. This is owing to the: absence of validated psychometric instruments, complexity of target populations, use of small sample size, lack of follow-up of behavioral variations and positive information effects as well as negative ones in the short, medium and long terms on the knowledge, and acceptance of consumers regarding irradiated food. Reproducibility is the ability of other researchers to obtain the same results when they reanalyze the same data (Kepes et al., 2014).
Attitudes are important psychological constructs because they have been found to influence and rule many behaviors. Brewer et al. (1994) proposed that six factors dominated respondents' attitudes towards the safety of their food: (1) chemical issues, as food additives and hormones; (2) health issues, such as cholesterol content; (3) spoilage issues; (4) regulatory issues; (5) deceptive practices; and (6) ideal situations, such as time required for pesticide safety assessment. Awareness, knowledge and judgment can also be affected by habits and perceptions that result from social, cultural and economic influences, philosophical perspectives, etc. (Wilcock & Ball, 2014).
As for the validation of the research instruments used, it has been observed that most of the instruments (83.3%; N = 55) applied in the researches of the selected articles did not present any description of evidence of validity for their construction, that would enhance the reliability of their research findings. Only in 6.1% (N = 4) of the total articles (Johnson, 1990;Wie et al., 1998;Thompson & Knight, 2006;Thompson et al., 2007) validated instruments were used explicitly, greatly improving the reliability of their results and conclusions. The instrument proposed by Johnson (1990) was developed following a review of the pertinent literature and consultation with professionals knowledgeable about food irradiation (content validity). They performed a pilot study and presented the Cronbach alpha coefficients (reliability). In the instrument of Wie et al. (1998), the content validity was assessed by three faculty members knowledgeable about the topic area. A pilot test was conducted, with several questions modified in order to enhance clarity and conciseness. Cronbach's alpha test was run to examine reliability. Thompson & Knight (2006) developed an instrument, called the Food Irradiation Educator Survey (FIES), to determine food irradiation beliefs and educational outreach of family and consumer sciences county extension agents. To define the constructs to be measured, a research review was performed and the judgment of experts was required. In order to establish content validity, three identified experts in the field of food safety and food irradiation reviewed each item for accuracy, appropriateness and adequacy. The face validity was also performed. To determine validity and reliability of the instrument, exploratory factor analysis (construct validity) and the Cronbach's alpha (reliability) test were conducted. Thompson et al. (2007) modified the instrument already validated by Thompson & Knight (2006), the FIES. The modified instrument was called the Food Irradiation Teacher Assessment (FITA). Construct validity was determined through exploratory factor analysis. Construct validity was also established through theoretical fit. Three experts associated with the field of food irradiation and food safety reviewed all items of the FITA for content validity and three educators reviewed it for face validity. Cronbach's alpha (reliability) test was performed.
According to Messick (1989), validity is an integrated evaluative judgment of the degree to which empirical evidence and theoretical justifications support the adequacy of inferences and actions based on test results or other modes of evaluation.
According to the American Educational Research Association (2014), validity refers to the degree to which evidence and theories support interpretations of test scores for certain uses proposed for it. The validation process thus requires gathering a substantial amount of relevant evidence to provide a sound scientific basis for interpretations of the proposed scores. Then, there is a need for methodological adequacy for the construction or adaptation of psychometric instruments in order to ensure that future research uses validated instruments.

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Findings from this work confirmed that positive information tends to improve the image of irradiated food while negative information tends to impair this image. At the same time, negative information becomes stored in the consumer unconscious, prevailing over positive information.
Recent research has suggested that information about the fundaments and benefits of food irradiation leads to positive changes in consumer perception and buying decision (Nayga et al., 2005). The acceptance of new technologies of food production and processing by the consumers is directly related to the credibility and trust in the sources of information. When adequately informed about the food irradiation technology, most consumers will react positively towards irradiated food (Frewer et. al., 1995(Frewer et. al., & 1996. Thus, it is important to evaluate new strategies to be used in the dissemination of information about irradiated food. In addition, the use of the Radura symbol on the label of irradiated food is important to ensure the sense of food safety for the consumer. It is important for consumers to believe in the referendum of the regulatory bodies, since the approval of any raw material, ingredient, food additive and unitary operation, related to the processing and conservation of food passes through compliance with specific protocols that guarantee food sanitation by part of the manufacturing industry. This study showed of meeting consumer expectations and preferences during purchases and that the disclosure of the Radura symbol meaning is crucial, corroborating with studies showed that this symbol brings a sense of confidence and security to the consumer, while the simple writing that the food was irradiated can bring a sensation of insecurity to the consumer Studies in the United States, France, China, Brazil, Argentina, Canada, Chile, England, Thailand and Turkey have shown that the use of marketing information tools, such as videos, folders, addressing the benefits of food irradiation, such as information material from government agencies and/or consumer protection organizations, tend to boost consumer confidence, positively impacting the acceptance of irradiated food (Modanez et al, 2016).
The flow of positive and negative information directly influences the knowledge about irradiated food causing impacts on the willingness to purchase them. In addition, when informed about the benefits of irradiated food, consumers tend to accept them better, even at higher prices. In contrast, consumers in developing countries are less willing to buy irradiated food.
Pillai & Shayanfar (2017) believe that Radura's presentation would add value to irradiated food, and may be a market differential. Moreover, in the context of transparency, consumers should be provided with information about the processing type applied to food, such as food irradiation.
Although the studies were conducted with a statistically significant number of participants, only 24.2% (N = 16) of them presented representativeness of the population that they meant to analyze, considering the high diversity of the sample and its unique characteristics, which severely limit the extraction of the sample of interest. It is a matter of good sense to admit that the sample from a city within a given country significantly represents the entire population of the country under analysis. Thus, more cities should be surveyed in order to conclude that the national population is indeed represented by the people surveyed in the study, as in the study of Frenzen et al. (2001), who sampled the residents included in the Foodborne Diseases Active Surveillance Network (FoodNet), covering 11% of the US population.
While most articles analyzed (70.8%; N = 50) cannot be considered representative of the sample and some do not even have a clear methodology to define their representativeness, in 84.9% (N = 56) of the articles, sampling was proved to be clearly random. Randomness of the sample reduces the bias of responses. Regarding the criteria for including articles in this systematic review, it has been observed that most of them (87.9%; N = 58) presented welldefined criteria for inclusion and/or exclusion of the sample of interest. Others, neither presented clearly defined criteria, causing doubts to the reviewers, nor such criteria were clearly defined. Inclusion criteria of a sample should be clearly defined, so as to reduce the response bias.
Statistical inference, in its classical approach, is based on the simple random sample, a method that requires each member of the population to have an equal and independent chance of being selected (Zar, 1996). However, most surveys do not use simple random sampling, in part because of budget constraints, in part because of time limits associated with collecting a large amount of information over a large geographic territory. As a result, other probabilistic methods are generally used in population-based surveys, such as stratified sampling and multi-stage 481 cluster sampling with unequal probabilities of selection to ensure sample representativeness (Cochran, 1977). Therefore, by ignoring sample representativeness, traditional statistical analysis, under the assumption of simple random sampling, can produce inaccuracies for both the average estimates and the respective variances, compromising results, hypothesis tests and research findings.
With respect to data processing, it has been verified that statistical analyses provide the information needed for data interpretation, according to EFSA (2010), which recommends that findings from research works should be reported regardless of the statistical significance of their results.
Finally, the eight articles classified as low RB were published in journals with IF greater than 5.01 and only the work by Teisl et al. (2009) had an impact factor of 3,688. The Impact Factor is an indicator used by development agencies, although the use of citations metrics is questionable, because the number of journals per area of knowledge is very different from area to area, as well as self-citation, variation in the number of references per article in each area, regionalism in some areas and journals, among others (Garfield, 1994(Garfield, & 1996. In addition, it is known that IF alone does not qualify the study from the scientific point of view. In the 34 years since first article on 1983 was published, the average number of publications corresponds to approximately one per year, but it is worth mentioning that there was a time gap of 6 years with no publications (1984, 1985, 1991, 1994, 2012 and 2013). The year of publication is another parameter to be considered, because the most recent articles describe more detailed timelines of information as consumer knowledge is linked to time. Thus, the more recent an article is, the greater the timeliness of the information provided will be. It is likely that this scenario reveals that the topic "food irradiation" is not on the agenda of most researchers, even researchers in related fields, or that "irradiated food" is a subject treated with some restrictions the repercussion and misconceptions conveyed both in academia and in the media.
The major findings from the present systematic review support the claim that developed countries are more acquainted with the topic -food irradiation‖ and consequently tend to consume more irradiated food. The degree of awareness concerning the benefits of food irradiation in the USA is, in general, fairly good among the American population. In Asia, knowledge about irradiated food tends to be better than in other countries, especially in Japan, due to the socio-cultural scars that the atomic bombs of Hiroshima and Nagasaki left on the population in August 1945. In contrast to the findings for US and Asia, the results found in Brazil, in Latin America and the Turkish were indicative of the low level of information disseminate and poor knowledge a regarding irradiated food.

Conclusion:-
A systematic review is a viable tool to assess consumer knowledge and this one is focused on how potential consumers view irradiated food. Most consumers are unaware of the benefits of irradiated food and developed countries tend to exhibit higher levels of knowledge on food irradiation and acceptance of irradiated food than developing countries. Researches have showed that educational actions favorable to irradiated food positively influence consumer attitudes, while unfavorable information leads to negative responses towards them, including rejection. In the last years, developed countries, such as the United States, tend to have a better willingness to buy irradiated food, while developing countries show greater resistance.
The importance of the use of validated psychometric instruments for data collection is emphasized and new research on consumer knowledge on irradiated food in developed, underdeveloped and developing countries is suggested as a research agenda, in order to evaluate the feasibility of educational campaigns and encourage the consumption of irradiated food. The impact of educational programs was seen as being of fundamental importance for the acceptance and breaking of paradigms on irradiated food. New trends in the field of education and distribution of irradiated food to consumers should be thought of as a way of encouraging a new view of consumer acceptance and empowerment in market relations.
Funding resource:-This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.