The Connections between Ecological Values and Organic Food: Bibliometric Analysis and Systematic Review at the Start of the 21st Century

: This paper addresses the ﬁeld of study relating to ecological values and the production, distribution, and consumption of organic food products, aiming to contribute to the consolidation of scientiﬁc knowledge in this area of study. This article refers to a bibliographic review in the Web of Science database. It also involves bibliometric analysis of the results of this bibliographic review using the NVivo program. The main results classify the number of articles published on the basis of the methodology used, the number of countries in the analysis units, the central themes of the study, and the type of organic food considered in the bibliography analyzed. It also classiﬁes the articles with the greatest impact in relation to the number of bibliographic references, in addition to detailing the universities, institutions, and journals with the largest number of contributions in the ﬁeld of study. The research concludes by identifying that most of the articles apply a quantitative methodology and address generic aspects of organic food. This study identiﬁes a need for further research in relation to speciﬁc organic foods, and for articles that introduce comparative analysis at the international level.


Introduction
The phenomena studied in this paper need to be put into context, considering that the ecological and logical values that influence the consumption of organic food are framed within larger processes of social dynamics, such as the growth of new social movements, the emergency of postmaterialist social values, and the need to develop healthy lifestyles to maintain and improve the health of the population. From this, we show that the roots of such value-driven and behavioral logic derive from the growth of environmentalism, which is considered one of the key vectors in what are known as the new social movements, which were born during the last five decades of the 20th century.
These new social movements, as considered in new political theory [1,2], have politicized questions that do not fit comfortably into the binary code of the universe of social action that underlies liberal theory, such as the division between the public and private spheres. The field of action of the new social movements is a noninstitutional political space that has quickly come to the attention of political parties, as they have provided ground for harvesting "political sensitivities". This materializes in electoral support from these groups through incorporation into their electoral programs. Political parties have even been created whose existence institutionalizes these new social movements, such as the Green party (Die Grünen) in Germany. From the political ecological movement, we reflect on the relationship among society, the system of production, its natural environment, and its repercussions for the future of humanity at the global level [3].
We drew on Meluci [1] for an exhaustive list of the new social movements, which include the student movement, feminism, citizens' movements, environmental struggles, the mobilization of consumers and users of services, the defense of ethnic and linguistic minorities, community and countercultural movements, struggles around health, and many others. The most interesting of these for this article are environmentalism and those relating to health and quality of life in the widest sense, together with the mobilization of consumers through ecological values.
It is obvious that there is a deep and powerful correlation between general socioeconomic conditions and the presence of a value-driven and attitudinal universe of new social movements, especially in the case of environmentalism, as Inglehart [4] pointed out in his renowned work on postmaterialist values. However, it would also be correct to say that such values can also be detected in other economic and social contexts not reflected in the existence of major figures in macroeconomic development indicators, as demonstrated by contributions linked to the activist and intellectual current of environmentalism among the poor [5].
We should not overlook the fact that the burgeoning environmental awareness among the population will be marked by value-driven, attitudinal, and behavioral dimensions, as environmental awareness is a theoretical construct, whose measurement is of transcendental importance in considering its actual spread [6,7].
We continue our contextualization exercise for the links between ecological values and consumption of organic food by pointing out that the social-environmental movement and the emergence of post-materialist values among the population are closely connected to another process marked by a constant struggle by citizens and the public powers to achieve a dignified quality of life. The paradigm of the search for what is healthy is becoming an achievable utopia. Indeed, many sources point to a strong relationship between quality of life and health [8,9], considering the former as a new parameter to be taken into account. Indeed, food consumption habits are often subsumed into a wider heading to fit them into healthy lifestyle habits [10], adding other wider dimensions to the food dimension, such as sport and many others. We also need to underline the emergence of a number of significant central concepts for these analytical spaces, such as ethical consumption [11,12], which combines ethical parameters into discerning the behavior in the population's consumption patterns. Ethicalness, as the guiding principle of consumption, opens the door to considering the benefits demonstrated by organic food, which include the virtues of supporting producers who respect the environment, the preservation of local varieties, and defense of the intrinsic quality of these as a defining trait, through which customers are attracted to the market niche of ethical consumption.
It is also important to note that the concept of quality of life is considered to transcend classes and is strongly linked to the field of healthy lifestyles [13]. This is where the associations with healthy food habits can be most clearly seen [14]. This includes the consumption of organic food [15] as a way to contribute to achieving healthy lifestyles through food habits consistent with that principle [16]. The value-driven, behavioral, and motivational circles [17] that surround organic food are essential for understanding their close relationship with major phenomena that characterize this type of alternative healthy consumption [18], which is marked by social distinctions [19].
The emergence of new patterns of consumption for organic food products is also considered an identity or social differentiation strategy [20]. This is driven by values such as protecting the environment and food independence, resulting in the production and consumption of local food products demonstrated to be of high quality [21].
In turn, buying habits also include a series of processes that present organizational structures and associations of multiple types, such as groupings of organic producers, the setting up of pop-up organic markets, associations of consumers of such products, urban organic farms, and so on [22]. Another dimension to be considered is that connected with knowledge about food in the widest sense, particularly with regard to the organoleptic properties of foodstuffs [23], their source (for example, designations of origin), issues relating to labeling [24], food quality (for example, protected geographical indications), food safety (traceability of production), and food sovereignty [25]. We also have to consider the supply of food, which is characterized by the need for short distribution chains [26], the preferable choice of local foods, and the purchase of seasonal foods with small environmental footprints [27].
It is also appropriate to highlight the current concern about and research into the production of products derived from the use of genetically modified seeds. This is seen by many consumers and others interested in ethical, ecological, and environmentally friendly consumption [28], who value traditional varieties, as a marketing strategy that is out of tune with their lifestyles [29] and part of the incessant thirst for profits [30].
We should underline that the situation of limited availability of appropriate distribution channels also represents a cost in terms of the time involved for the consumer in shopping for such products, compared to the ease of shopping in supermarkets and other local stores [31].
There has been a notable increase in consumption of ecological products over several decades, leading to the argument that ecological consumers are now recognized as a constantly increasing market niche [32,33]. This status is clearly reflected in the attention paid to the correct use of traceability, labeling, and cultivation processes in the ecological production sector in the European Union, for example, but which also extends to numerous other regions [34]. The cost-benefit relationship in the consumption of ecological products is a subjective aspect that can be modified through the marketing of such products [35]. The price of ecological products is seen as the main hurdle to developing the marketing of such products [36]. We have to consider the question of the premium prices of some organic products [37], social distinctions [38], and the achievement of sustainability in the widest and most comprehensive sense. These are essential when considering the relationship between attitudes and behavior in relation to ecological values and the consumption of organic food [39]. A number of studies since the 1990s have suggested that values relating to environmental awareness are linked to the purchasing of organic food products [40,41]. According to the study by Frazen and Volg [42], involving an international comparison of 33 countries, the results indicate that the countries in the study with the highest degree of environmental concern in 2010 were Switzerland, Canada, Denmark, Finland, and Sweden, all of which have high levels of economic development. The countries in the study with the lowest levels of environmental concerns were Poland, Ireland, Hungary, and Portugal. According to the main findings, the environmental awareness of people in different countries depends mainly on individual sociodemographic characteristics, particularly age, gender, education, income, and postmaterialist values. This study also identified the importance of the gross domestic product (GDP) per capita of the countries analyzed for the presence of values related to environmental awareness. This paper also found a decrease in levels of environmental awareness between 1993 and 2010, and it highlighted the importance of government in fostering environmental awareness through the education system, as well as the need to develop policies based on environmental sustainability [42].
The market for organic agriculture has grown rapidly. Some estimates suggest organic production is worth 25.5 billion EUR worldwide, with approximately 0.75% of cultivated land being dedicated to organic production [43]. Some major studies have analyzed the market for organic products in European countries, under the Organic Marketing Initiative and Rural Development program, which has the primary objective of identifying the main marketing and communication strategies and how to enhance them, while raising the profile of favorable environmental and social effects in Europe's periphery regions. Some studies also highlighted the ongoing increase in the consumption of organic food in Europe [44]. For example, the market for organic products in Germany increased from 5.85 billion EUR in 2008 to 8.62 billion EUR in 2015. These studies also show the importance of retail channels for the distribution and sale of these products [45].
Our main objective in this research is to prepare a categorization based on the issues in contributions to journals of internationally recognized quality and prestige related to ecological values and organic food. We also undertake a systematic review of these publications to clarify the structure of the state of this question and the current lines of research in the first two decades of the 21st century. The analysis of studies of organic products has been performed at the international level, as the database used for the bibliographic study was Web of Science, which publishes papers from international sources.

Materials and Methods
The methodological design used in the preparation of this systematic review article and bibliometric analysis is marked by use of a strategy aimed at mixed quantitativequalitative profiling. This methodological approach was chosen due to the volume of information and units of analysis used, i.e., the bibliographic references to be obtained. This involved implementing two parallel procedures. The first involved a search using the Web of Science bibliographic resource search engine, which returned the universe of bibliographic references to be analyzed applying the strategy of the PRISMA guide (Preferred Reporting Items for Systematic reviews and Meta-Analyses), which is often used in this type of work [46]. The second involved analysis of the information obtained (bibliographic references in relation to the issues) using the NVivo (version 11) qualitative data-processing program. Incorporating this technology into the research helped with analyzing the data and its presentation through charts, making it more attractive and versatile [47][48][49].
Its main advantage is that it can handle an almost unlimited number of categories and subcategories, which can compare then be compared in an abridged form using intersection matrices [50]. It also offers the option of presenting the results using techniques more common in other programs (for example, SPSS), such as cluster analysis. This enabled bibliometric analysis of the results, with subsequent research to develop a systematic review of the categories to be prepared using the NVivo program and its tool for creating working matrices.
Following the guidance in the PRISMA guide, we use a flowchart to detail the procedure used to obtain the bibliographic references through the Web of Science search engine, so as to represent the main strategy for the selection of bibliographic references and set out the results graphically.

Identification
We initially performed an advanced search of the Web of Science (WOS) [51] using the Boolean operator AND to include ecological values and organic food-the main items studied in the research-as the search terms. This resulted in the following search formula: TS = (ecological values AND "organic food").
The search of bibliographic references was performed in the Core Collection of Web of Science database, which includes the following databases: SCI (Science Citation In-

Screening
The results of this database search were then screened to refine the final set of references. A number of filters were applied in relation to the date (limited to publications that appeared between 2000 and 2020) and to limit the research domains to the social sciences, (with the most important being psychology, market research, agricultural economics, rural sociology, environmental psychology, analysis of agricultural production, rural anthropology, and studies of consumer behavior), giving precedence exclusively to articles in scientific journals, which are the highest-level instruments for disseminating information in the scientific and academic fields.

Eligibility
This search returned 93 results which were then subject to bibliometric analysis. This was followed by systematic review of the 10 references with the largest number of citations, according to the criteria in the Web of Science search engine, which reflects the significant impact of the research work in these articles. This type of procedure for selecting references has already been used in other research published into these issues [52,53].

Included
This methodological design was completed by applying content analysis technique for the various categories studied, particularly with regard to questions about the years in which the articles were published, the type of methodology used, the geographic context of the research, and the main issues. With regard to the bibliometric analysis, the research considers the lead institutions to which the authors are attached, the main journals for publication of articles on the issue being studied, the authors with the most bibliographic citations, and the articles with the largest number of bibliographic citations in Web of Science. This extensive analysis of the categories enabled a thorough narrative description of the current state of play in this line of research.

Results
We now present the flowchart ( Figure 1) established for this research, according to the PRISMA guide, which includes the main aspects in the identification, screening, eligibility, and included processes, which were applied to all of the bibliographic references identified in the search process. All the data obtained are included in Appendix A.
Below, we display Table 1, showing data relating to the year of publication of the articles. Source: in house based on Web of Science (WOS) search engine data. The data in this table show that the number of references has increased considerably since 2014, with the period from 2014 to 2020 providing a significant volume of the references, i.e., 54 of the 93 references that represent the universe of analysis for this article. However, one noteworthy aspect is that only six references out of this total were published in 2020. In this regard, we have to note that the number of articles registered in 2020 is limited by the time when the searches were conducted (September 2020). Leaving this fact to one side, we argue that the research interest and the volume of publication of references focusing on issues relating to ecological values and organic food is increasing. The data in this table show that the number of references has increased considerably since 2014, with the period from 2014 to 2020 providing a significant volume of the references, i.e., 54 of the 93 references that represent the universe of analysis for this article. However, one noteworthy aspect is that only six references out of this total were published in 2020. In this regard, we have to note that the number of articles registered in 2020 is limited by the time when the searches were conducted (September 2020). Leaving this fact to one side, we argue that the research interest and the volume of publication of references focusing on issues relating to ecological values and organic food is increasing. This is, therefore, a line of research and publication that is likely to achieve considerable weight in the near future. Table 2 displays data relating to the signatory authors of each reference so that we can analyze this aspect in depth. Source: in house based on WOS search engine data.
The interpretation of the data on the number of authors per reference enables us to say that articles signed by two (25.8%) or three authors (23.7%) account for more than half of the references. The data for the total number of authors are also noteworthy. This shows that 271 authors were involved in writing the 93 references. We can draw out some very significant features of the bibliometric analysis from this, such as that the average number of authors per reference is 2.9. The mode resulting from this frequency distribution is two, which is the number for 24 of the 93 references. It is noteworthy that over 86% of the references have between one and four authors, making contributions signed by five or more authors much less significant. Therefore, in this line of research the research teams that sign the articles are usually not very large in comparison with other scientific disciplines, where the average number of authors and the composition of the teams are much larger. Table 3 shows data for the methodology, the geographic context, the central issues, and the foodstuffs to which the articles relate.  It is noteworthy from the interpretation of the data with regard to the methodology used that the majority of the references use quantitative techniques (63), with far fewer references being based on qualitative techniques (25). The articles offering research results based on mixed methodology (i.e., using both quantitative and qualitative techniques) are hardly significant (5) compared to the other methodologies. We, therefore, found that quantitative research techniques are used in the majority of cases in the line of research being analyzed, although qualitative methodologies are also used, with the objective of analyzing this issue in greater depth.
The data for the geographic dimension show that almost 90% of the references focus on the geographic context of a single country, with only one out of 10 references using a geographic context extending beyond the borders of the nation/state, in the cases of comparative research involving two countries and research with a multinational approach. We can, therefore, say that there is a pronounced shortfall in published scientific output offering comparative analysis at the international level in relation to these issues.
The next category used to focus the analysis is the foodstuffs considered in the research work being considered. The resulting data show that most of the articles (58.1%) are based on a perspective of the research topic (production ecological and ecological values) that takes a general approach (66), with few studies focusing on a particular organic foodstuff or group. This situation results in the analysis being excessively wide-ranging. It does not focus on the issues/concerns or areas of application of the spectrum of values and behaviors involved or on the presentation of important elements in relation to foodstuffs. Rather, the analysis refers in a wide sense to the set of social values and to organic food as a whole, making it impossible to become more granular or detailed about this. The foods that receive the most detailed attention, in order of quantitative relevance, are vegetables (6), organic milk (4), and fruit (3). This analysis displays a significant dearth of research into specific foodstuffs which are a central aspect of the whole topic.
Lastly, we present data for the category of central issues developed in the bibliographic references. This shows that the largest volume of references (30) relates to the study of organic production. It is noteworthy that the attention of these focuses on aspects relating to production, as that is where the main difference between conventional and organic production is to be found. The most numerous research profiles include research into organic producers and their internal characterization, through quantitative techniques such as questionnaires. The presence of articles where the central issue is ecological consumption values (24) is also noteworthy, as this area complements the production area referred to initially. As we have already said, the field of production has been studied as it is of vital importance for this line of research, but more work also needs to be done on the consumption dimension. This is where differences in the way that ecological values manifest themselves in consumer behavior take center stage. These articles focus on identifying which explanatory variables are or particular importance among consumers of organic products, proposing that naturalness, sustainability, and buying products cultivated without the use of chemical products are essential in explaining the logic behind such consumption. Third in order of importance is food quality, which is considered in a substantial number of the research works (13). These use empirical elements to demonstrate the benefits shown by organic food production across a wide spectrum. They argue that the lack of substances that are harmful to health, together with the better range of organoleptic properties in organic food, justify their enormous degree of alimentary safety, and their commitment to the survival of local producers makes them guarantors of the principles of comprehensive ecological sustainability. The traceability that they provide, together with strict controls on certification and labeling, fosters the whole process, avoiding the risks associated with food scares. This area is addressed in detail in the references with which we have been working.
This area is completed by other, less significant, types of core issues, which are the price of the products (8), alternative production/consumption channels (6), certification (7), and labeling (5).
The next table offers data on the main institutions (universities, research institutes, companies, associations, and so on) to which the authors of the publications we are analyzing are attached. Table 4 provides data on the universities and research centers accounting for more than two authors among the 271 authors of the 93 bibliographic references selected. The most significant data relate to the large number of institutions from European countries, with the largest contributors being Italy, contributing 13 authors from three institutions, the United Kingdom, contributing 12 authors from five institutions, and Germany, contributing eight authors from two institutions. As we can see, only three of the institutions (Kansas State University, University Central Queensland, and University Guelph) in the table are not European. We now focus on the academic publications that received the articles being considered. The next table lists the names of the scientific journals, the countries where they are edited, and the references they published in the period considered in this paper. Table 5 lists the main journals that received the research into ecological values and organic food for publication. An initial examination shows that the British food journal is in first place with 17 references published in the period 2000 to 2020. This journal is based in the United Kingdom. Considering the data set out in Table 4 above in relation to the institutions from which the authors come, we can argue that the research interest and the receipt of work on these issues are very considerable in this country. It is also the home of other journals, such as the Journal of rural studies, Ecology of food and nutrition, Food policy, International journal of consumer studies, Sociologia ruralis, and Agribusiness. The United Kingdom, therefore, is the country with the most journals (7) and most references (30) published on these issues. The Swiss journal Sustainability is in second place with five references on these issues. The Netherlands has the second most journals dealing with these issues, with six journals publishing 17 references. It is extremely interesting that all of the journals in this table are in the northern hemisphere and, in many cases, these are based in countries with very high levels of concern about the environment [54]. In Table 6, we consider the category of authors responsible for more than one reference. This table includes all of the authors in our selection with more than one reference for the subject being studied. In other words, these are authors who are developing this line of research and disseminating it through publications with significant impact at the international level. The author with the largest number of published articles of the 14 authors who have published on the subject being studied is Lockie (4). In addition to being in this table, this author, who is based in Australia, has also received a very large number of citations. He also features twice in the table of the 10 most cited articles on these subjects (Table 7). Lockie can, therefore, be considered the most significant author on these questions. Escobar-López, Mosier, and Aldanondo-Ochoa all have the same number of articles published on Web of Science on the subject being studied. They are all responsible for four articles in our search results. They are followed by Zanoli, from Italy, with three articles and, finally, a small group of authors with two references, including Seyfang and Halpin, who also have references in the top 10 in Table 7. We complete this section of our article with a systematic review of the 10 articles that have received the most citations.
We can highlight two important broad-brush elements from the data in this table. First, there are three articles signed by Lockie [56,59,61], which means we can say that he is the author with the largest volume of citations for the issues this work is investigating. His line of research has covered the issues considered in this article with regard to the relationship between ecological values and organic food. Second, we can see a very recurrent presence of a generalized effort to deploy methodological designs based on empirical research (whether from a quantitative or qualitative perspective), as the main objective of the 10 articles analyzed is the characterization of the subject from an empirical approach, whether with regard to consumption or with regard to production. Putting an empirical face on everything related to ecological values and organic food appears to be a shared objective among the articles with the most citations. The next table summarizes the main categories analyzed in the 10 most cited articles. Table 8 shows aspects relating to the 10 articles with the most citations in the area of study in relation to the independent variables analyzed in the methodology, the central study topic, and the type of food analyzed. It also summarizes the central objectives of the research and the main results of each of the articles considered.

Summary of the Research Results
This highly important set of six articles with great academic impact predominantly relies of quantitative methodology, with three articles involving qualitative methodology and one using a combined quantitative and qualitative methodology.
With regard to the central study topics, four articles study organic production, three are related to the study of ecological values, two relate to labeling of organic products, and one addresses short distribution chains for ecological products. All of these articles deal with organic food products in general, rather than studying any particular product. We now briefly summarize the objectives studied and the main results of each of the 10 articles with the most citations.
Taking a more focused systematic approach, we start with the article by Seyfang [26], which takes an empirical approach to analyzing local organic food networks. This study uses a mixed methodology to discuss the role of these local organic food networks and contextualizes them in a wider theory referred to as new ecological economics. This work starts from the hypothesis that ecological citizenship is a driver for consolidating sustainable "alternative" consumption, through the expression of consumer behavior, such as purchases of local organic food. The results show that the initiative of creating and enhancing local organic food networks offers a real possibility for sustainable alternative consumption. Seyfang concludes that achieving the implementation of ecological citizenship could become a powerful motivating force for sustainable consumption behavior and considers the political and research implications of this. This is followed by Guthman [55], with the second largest number of citations. This paper reports research in which the main objective was to assess the suitability of organic food labels in the current context of the global market for food products. It uses a Polanyanian approach to argue that voluntary labeling of local production enables resistance to the incessant process of delocalization of food markets. In the author's opinion, the incorporation of this labeling could represent a way for consumers to express their sovereignty in a market saturated with products from distant and exotic markets. The success of this food identification strategy depends on the decision to consider this labeling and to value the source positively or negatively. Guthman's approach [55] involves putting the emphasis on the suitability of labeling depending on the foodstuffs. Lockie [56] presents an article focusing on analysis of the choice of organic products in Australia. This paper researches a number of dimensions (attitudes, motivation, demographics, and behaviors) that influence the choosing of organic food in that national market. He argues that concern about the natural properties of foodstuffs and the sensoryemotional experience of eating are the main explanatory factors for increasing levels of organic consumption in Australia. His research shows that gender is a highly significant explanatory variable for the choice of organic food. He shows that income, age, political and ecological values, and willingness to pay a premium price for environmentally respectful and safe food have considerably greater effects on Australian women.
Fourth in order of the number of citations is the research by Lotter [57], which, under a very generic title, sets out the situation in organic agriculture in the United States at the start of the 21st century, taking an econometric approach. The article also assesses the presence of organic agriculture in the rest of the world, arguing that the consumption, sale, production, and value of the market for organic production have all increased substantially. The paper also compares figures for conventional and organic farming and agriculture. The author concludes that, if a large scale conversion process of conventional agriculture into organic agriculture were possible, this would not result in a hypothetical situation of food shortages, as this would be possible in a complementary way, due to the drastic reduction in meat consumption. The study uses well-constructed empirical elements to show that current organic agricultural systems consistently outperform conventional agriculture in showing resilience when there are shortages of water resources for production. Lotter's work is an important empirical contribution for valuing organic agriculture, based on substantial econometric underpinnings.
At the halfway point in this systematic review of the articles with the most citations relating to ecological values and organic food, we find the work prepared by Aertsens and team [58]. This was published in the British Food Journal, one of the leading publications in the area. This empirical analysis focuses on the Flanders region of Belgium, investigating the influence of consumers' knowledge with regard to their attitude, motivation, and consumption of organic food. He uses a quantitative methodology based on a questionnaire, the results of which are subjected to a range of multivariant statistical techniques to identify possible obstacles to increasing the consumption of organic food, and the relationship of this to levels of knowledge about the properties of such foodstuffs. The main findings of this research are limited to uncovering and comparing perceived barriers, which are excessively high prices and lack of availability. It also finds that objective and subjective knowledge about the production of organic food has a positive correlation with its consumption. In other words, the more knowledge consumers have of the production and benefits of organic products, the more likely it is that they will buy them. The most noteworthy result of this article is that it was the first to describe the impact of knowledge on the consumption of organic food in so much detail, as it uses data to assess the impact of knowledge and various other factors on the consumption of organic food, raising the profile of motivation, attitudes, and behavior in relation to the consumption of organic food.
The sixth most cited article is by Lockie and Halpin [59]. This deals with the transformation process begun by organic agriculture with a view to potential convergence with conventional agriculture, which is more commonly referred to as "conventionalization". This research work discusses the potential convergence of organic and conventional agriculture in the Australian context. They base their approach on setting out arguments that establish differences between industrial organic producers, which give them certain similarities to conventional producers. They also examine the minority discourse of a group of activists belonging to social movements more tuned into the critical spirit who continue to use traditional organic production practices. The authors use surveys to demonstrate that there were no major differences between large organic producers-who are potentially conventionalized-and small producers. They also argue that the convergence process of conventionalization of organic production would not enable the capture of a large market share for production with organic certification compared to organic products from the conventionalization of organic agricultural production in Australia.
We then analyze the contribution of the Dutch research team led by Verhoog [60], the main objective of which was to study the role of the concept of naturalness in organic agriculture. The central element of this work involves proposing a profound explanation for the natural/unnatural dichotomy in the characterization of the differences between conventional and organic agriculture. This work used the in-depth interview technique to produce a much more refined profile of the conception that organic farmers present of what is natural. Their main contributions involve establishing the three approaches that are found in organic agriculture, namely, the elimination of the use of chemical products, agro-ecological production, and a focus on integrity. The naturalness offered by organic production fits into these three perspectives and, thus, manages to appear in the collective discourse of the producers, which can then be incorporated into the ethos of organic products themselves. At another level of results, it was found that these approaches can also result in a change of attitude among farmers to the extent that they pass from conventional to organic agriculture. These also exist in the attitudes of consumers of organic foodstuffs.
The eighth most cited work is Lockie's "Responsibility and agency within alternative food networks: assembling the 'citizen consumer'" [61]. This author considers that the needs expressed by consumers for enhanced information from the food industry, in terms of food quality and safety and environmental questions, lead to redefining food consumption as an expression of citizenship that alludes to collective rights and responsibilities. However, this new situation is being conditioned by the emergence of new formulas alien to the neoliberal approaches of commercial interaction between consumers and producers. Indeed, the launch of alternative food networks is focusing expectations on collective participation and consensus processes based on collaborative rather than conflictive principles. This is, therefore, moving away from the standards set by the market, fostering the mobilizing factor of well-informed and aware consumers. Lockie says that traditional elements, such as marketing, price setting, and food distribution are interacting to enable and/or obstruct mobilizing expressions of food citizenship. His main result mentions that reductionist configurations based on the principle of creating stereotypes of what is referred to as the "ethical consumer" obstruct access for people and environmental values, such as biodiversity and the ethical market. His approach is, therefore, based on a much broader and more inclusive construction of the concept.
The penultimate paper in our systematic review is a scientific contribution by Konstantinos Giannakas [62]. This Greek scientist has contributed an article explaining the asymmetries and consumption decisions in organic food product markets. His main concern is the supply of such products and analysis of their differentiation through labeling. He believes that it is obvious that the possibility of incorrect labeling has usually been ignored in economic studies of markets for labeled goods in general. His contribution, therefore, focuses on developing a model of heterogeneous consumers. He observes and assesses the effects produced by the phenomena of incorrect labeling on purchasing decisions and on the wellbeing perceived by consumers. Giannakas' main results are that certification and labeling are essential. The article shows the importance of correct product labeling to increase trust in the most highly valued aspects of these products.
The final paper in our ranking is by Clarke et al. [63]. This paper has the clear intention of identifying the spaces and ethics of organic food in the United Kingdom, through the largest supplier of organic vegetables in the country. The ethics displayed by the organic food system in the country ignore a number of core questions relating to the need to explore the ambiguities and disconnections inherent to the ethical practices of organic producers and consumers. Based on the case of the Riverford company, the researchers examine its production and distribution space for organic food, concluding that it is neither a tiny local counter-cultural farm nor a large transnational corporation. They conclude that Riverford simultaneously presents the production and distribution spaces for organic food in the national network, the regional distribution system, and the local farm. This leads them to conclude that the space is multidimensional and complex. In addition, in the case of this British company, the labeling of the organic products presents their benefits almost tangentially, focusing more on their ordinary characteristics, i.e., on the principles shared with other, nonorganic, food. As a result, the inherent ethical benefits of organic production are not communicated sufficiently clearly for consumers to fully appreciate them Lastly, before setting out our conclusions, Table 9 summarizes the results of this research work, clearly displaying the huge volume of information collected in the preparation of this article. Table 9. Summary of results.
The main results for the articles that used quantitative methodology (63) is that this type of methodology is the most common in comparisons of more than two countries (6), as the use of comparative data surveys, whether through a primary or secondary research strategy, can help to facilitate the production and analysis of results compared to the complexity of the methodology involved in performing qualitative comparative studies at the international level. The average number of authors signing the articles based on quantitative methodology is 3.03, with the majority being signed by two authors (16). The main issues studied are ecological consumption values (15), the type of organic production (19), and the type of labeling (5). These mostly referred to generic aspects of organic food, with organic vegetables being the subject of the largest number of articles (3).
With regard to papers based on qualitative methodology (25), 23 of the papers considered just one country as the unit of analysis. This publication type had an average of 2.64 authors per article, usually being signed by between three and four authors. The main subjects studied using qualitative methodology were the type of organic production (10), ecological values (7), and aspects related to food quality (5). Most of these papers referred to general aspects of organic products, with only studies relating to organic vegetables having a larger number of studies performed using qualitative methodology (3).
Fewer papers were prepared using a combined quantitative-qualitative methodology (5). These mainly considered a single country (4) and were signed by an average of 2.8 authors. The main topic of study was ecological consumption values (2), and the product studied in the most papers was organic milk (2).

Conclusions
We would like to conclude by summarizing the conclusions we have drawn from our research. On the basis of the data employed in this line of research, we can state that research interest and the level of publications focusing on ecological values and organic food are increasing. We can, therefore, state that this line of research and publication is in good health and looks like achieving substantial potential in the near future.
Our research into this topic reveals that the articles analyzed show a marked trend toward using quantitative research techniques. However, we did find some papers that applied qualitative methodological strategies, which were designed to achieve more intensive analysis of this issue. As a general rule, most of the papers did not have many authors and, therefore, this line of research is not characterized by large research groups. We can also say that the data obtained show a pronounced shortfall in published scientific output offering comparative analysis at the international level in relation to these issues. This is in addition to the fact that it would be desirable to have more research efforts focusing on specific foodstuffs, as most of the papers focus on organic food in general, overlooking the fact that zooming in could, in some cases, be central to the area being studied.
With regard to the institutions to which the authors are attached and the countries from which they come, there is a predominance of institutions from European countries, with the main contributors being Italy, contributing 13 authors from three institutions, the UK, contributing 12 authors from five institutions, and Germany, contributing eight authors from two institutions. The presence of other, non-European, countries is very low. Likewise, Lockie can be considered the most significant author in this specific area. The main journals that receive and publish articles in this area are located in countries in the northern hemisphere. In many cases, they are based in environments where consumption of organic food is already very significant, giving them a context of relevance and pertinence as a research area.
If we go further back in time, we find practically no papers on these issues. Therefore, extending the period for such studies would not improve the findings substantially. However, a challenge for the future would be for the scientific community that is interested in these research topics to perform other types of work considering other international databases to verify the findings outlined here.
Another limitation of the study relates to the period of the bibliographic review, which covers 2000 to 2020. The challenge of undertaking research with a bibliographic review of articles published in this field over a larger number of years needs to be considered. Another important factor in improving future work would be considering expanding the scope to include other international databases, such as Scopus. This could open up a significant field for work to consolidate and structure the scientific knowledge generated internationally with regard to the relationship between ecological values and organic food.
Based on these aspects, it can be concluded in general terms that there is a very generalized recurrent effort to implement design methodologies that develop empirical research, so as to offer the scientific community publication milestones to further consolidate this line of research, making the research results more robust and rigorous. We could also consider the ideas below, extracted from the main results obtained from the articles with the greatest academic impact at the international level, in the field of study of ecological values and the production and consumption of organic products.
First, it should be considered that ecological citizenship could lead to consolidation of a production model based on sustainable consumption.
Second, the correct labeling of organic products and the availability of information on the benefits of food based on such products, and information on the traceability of products with regard to their local production or the or air miles involved in their delivery could be key elements in boosting this market.
Third, the capacity to generate trust and attract new consumers of organic products from the conventionalization of organic production should be explored, as naturalness and other ethical aspects of an environmental nature seem fundamental in the choice and purchase of such products.
Lastly, the studies analyzed show that short distribution chains, correct labeling, product certification, and availability of information on the environmental and health benefits of food based on organic products could be a much more effective marketing strategy than conventionalization of organic production.