Content analysis

An analysis of the co-occurrence of key words and academic terms in the titles and abstracts and key words of the publications was carried out, following a co-occurrence method, showing only the elements connected with others, the normalization-strength of association method (FA), resolution of 1.5, 80% display scale, TLS weight, label variation size of 80% and core width 30%.

The complete counting method was established, with a number of records of each term ≥10 and a minimum cluster size of one. With the terms retained, the map for the visualization of the network was created, the VOSviewer v software was used. 1.6.9. (^{Center for Science and Technology Studies, 2018}). The algorithm was designed so that the terms that co-occurred were positioned closer to each other, with larger frames those with greater frequency.

Performance analysis

There are 204 documents registered from 1968 to September 28, 2018. The distribution of the publications is presented in Figure 1.

Figure 1 Distribution of publications on labeling, agriculture and consumers from 1968 to 2018 (September 28).  

As of 1998, the number of publications begins to increase, having years with higher scientific production: 2000, 2004 and 2012. The 80% of publications are concentrated after 2003, although 50% corresponds to the last five years, the average for the entire period analyzed is six publications per year, and for the last ten years is 11.6 publications per year.

Of the total of documents, 143 have been cited, accumulating a total of 3 365 citations. There are seven documents that have more than 100 appointments, seven have between 50 and 99 appointments, 49 have between 10 and 49 appointments, 58 have between two and nine appointments and 22 documents have an appointment. On average there are 23.5 citations per document for the period analyzed, Table 1 shows the ten most cited articles.

The ten journals, countries and institutes with the highest number of contributions publishing issues related to labeling, agriculture and consumer are presented in Table 2.

The five journals with the highest number of publications on the subject are: Nature Biotechnology, Journal of Cleaner Production, Chemical and Engineering News, Food Policy and Nature.

As far as affiliation is concerned, the universities of both the European Union and the United States stand out. The institution with the highest number of publications is the INRA Institut National de La Recherche Agronomique, followed by the Wageningen University and Research Center, the University of Wisconsin Madison, the University of Florida and the National Agriculture and Food Research Organization. With respect to the countries, the United States of America has contributed with 31% of the publications, followed by Germany, Italy, the United Kingdom and France. In Latin America, the leader is Brazil with eight publications, Argentina in second place with two publications, the rest are contributions from Colombia, Mexico and Chile who have a publication each.

Mapping of science

The information of the titles, summary and class words was analyzed with the VOSviewer program, which generates maps of terms, in networks, showing co-occurrence and relative impact of citation. Each map includes terms that occurred at least 60 times under a binary content, considering only the number of publications in which the term is presented regardless of the number of times the term is presented in each article individually (^{Yeung et al., 2017}). VOSviewer selected 49 terms that had the highest values to form a map that allowed a visualization of the thematic network, organizing them in three clusters with 997 links.

In Figure 2, the three clusters are observed: one that refers to producers, the other focused on consumers and a third related to regulations mainly by the Department of Agriculture of the United States of America (USDA).

Figure 2 Network visualization using the VOSviewer program. Note: because they are considered generic, the words article, data, person, sample, result, study, survey, time, method, number, application were eliminated.  

The consumers

The ultimate objective of agri-food production is to generate products for consumers, derived from this, the safety of food, as well as the conditions in which they were produced, have caused consumers to change their beliefs, attitudes and behavior. Same as reflected in patterns of purchase and consumption (^{Verbeke, 2005}) that impact the agrifood sector. In this same line of discussion, we find the distinction between compulsory and voluntary labeling. ^{Alfnes et al. (2018)}, in a review on this issue in farmed fish establish that mandatory labeling includes information on species, production systems (breeding or wild) and area of origin, while voluntary labeling includes information on sustainability, production organic, animal welfare, traceability and innocuousness.

The existing publications referring to consumers are about: types of consumers according to their values with respect to meat labeling that evidences animal welfare, environmentally friendly production (^{Sonoda et al., 2018}), willingness to pay (WTP) for wines labeled as produced under water saving systems (^{Pomarici et al., 2018}), appellations of origin or organic production (^{Troiano et al., 2016}), by traditional food production systems, which the consumer perceives as environmentally friendly and whose Food products are of high quality (^{Wang and Gao, 2017}).

An important part of the studies, assess the impact on the attitudes of consumers derived from being informed of various issues, such as: production under organic conditions or extensive livestock (^{Risius and Hamm, 2017}) or the acceptance of products that reduce the impact in terms of the carbon footprint (^{Lombardi et al., 2017}). These studies expose the need to inform consumers more and better.

In general, since labeling is the way information is provided to consumers, it becomes strategic to reach them effectively impacting the food industry, as well as the primary producer. Research warns that not all consumers appreciate the various labeling trends related to sustainability equally and that the success of the initiatives that are reflected in the labels is limited to consumer segments, without neglecting the importance of sensory attributes (^{Silva et al., 2017}) and personal well-being (^{Bruschi et al., 2015}), which largely explain the consumer’s behavior and preferences.

The producers

Consumers have played an important role in food labeling processes that directly affect agri-food producers. In general, they use ethical and ecological criteria to select products, which has made it imperative to evaluate the environmental impact and the use of resources in the production and distribution of food by producers, industry or food distributors. One of the tools that have been developed for these purposes and that is present in research related to labeling, agriculture and consumers, is the Life Cycle Assessment Life Cycle Assessment (LCA), which determines the environmental effects of a product, process or activity through its life cycle or lifespan.

The purpose of this tool is to compare between products, processes, and alternative services, in order to compare their life cycles and identify the parts where improvements can be made. Its main application has been in agriculture, industrial processing and agri-food products, with topics related to: emission of greenhouse gases, ecological footprint ecological footprint analysis (EFP), eco-labeling, environmental impact of the use of chemicals for the pest control, waste management, evaluation of production systems of salmon farms and apple production, among others (^{Canals et al., 2006}; ^{Pelletier et al., 2009}; ^{Roy et al., 2009}; ^{Bessou and Colomb, 2013}; ^{Gheewala and Mungkung, 2013}).

In general, these studies seek to guide producers on how to improve their processes from the point of view of sustainability. Another important component of the research that relates to producers is the environment. For example, the factors that influence the adoption of good practices to reduce pollution have been studied, concluding the need for certification and labeling schemes (^{Liu et al., 2018}); the labeling and training for the use of pesticides in Brazil (^{Waichman et al., 2007}; ^{Pedlowski et al., 2012} and certifications for biodiversity protection biobanks (^{Edwards and Laurance, 2012}).

A third line of research is the impact on producers of labeling and certifications, such is the case of ^{Mook and Overdevest (2018)} who found that fair trade acts more as a mechanism of social justice than as a market mechanism. In summary, the subject of interest and the producers can follow several aspects, from regulation, the environment, the effects on the producers, the processes and the products produced under different schemes of certification and labeling.

Legislation

Within the aspect of legislation highlight the key words of the United States, USDA and drug administration, this is explained because 31% of publications are from this country and their public institutions have high representativeness in various studies. Some authors focus on analyzing the efforts made by the government of the United States of America in developing labeling programs for various purposes, such as the program of antibiotic-free meat products (^{Centner, 2016}) or the labeling of allergens in food (^{Gendel, 2013}).

One of the most important issues in terms of legislation is the labeling of foods produced using raw materials based on genetically modified organisms (GMOs) (^{Bovay and Alston, 2018}) or nano foods (^{Graffagnini, 2010}). The use of GMO is the agricultural practice with greater adoption in recent times, which has caused consumers to claim the right to know what is in their food (^{Privalle et al., 2012}), as they are considered misinformed regarding this topic (^{Boccia, 2015}).

One of the reasons is the diversity of terms that are used, such as: genetic engineering, genetic modification or agricultural biotechnology, according to ^{Zahry and Besley (2017)}, consumers would accept more products labeled with the term genetic engineering. In these debates, the attention that the media has put on the subject has caused supermarkets to recognize the importance of having products on their shelves free of GMOs, where voluntary labeling has allowed their development as a market niche (^{Bain and Dandachi, 2014}). In summary, legislation, especially in developed countries, has been key to protect and inform about the foods available to the consumer.