Global scientific trends on aflatoxin research during 1998–2017: a bibliometric and visualized study
Aflatoxins are fungal metabolites associated with contaminated food products. Intake of aflatoxin-contaminated food results in serious health hazards and even death. Therefore, the aim of this study is to evaluate the global scientific output of research of aflatoxin by using bibliometric techniques.
This bibliometric study was conducted using Scopus database and classified the retrieved publications were classified from different aspects, including the countries/region of focus, journals, authors, institutes, citations, and content analysis to discover any hot and emerging topics. In addition, the bibliometric analysis of the international collaborative network and hot research topics were generated by VOSviewer© software version 1.6.10. The publication period was restricted in the search for two decades (1998–2017).
The search engine of the Scopus database found 9845 documents published in the field of aflatoxin. The USA is the top publishing source in the world (22.85%), followed by China (11.85%), India (9.32%), and Italy (5.25%). In earlier years, researchers focused on terms related to the topics of “sources and biosynthesis of aflatoxin”, “health effects by aflatoxin”, and “detoxification and treatment of aflatoxin”. However, in recent years, researchers pay more attention to the topic of detection and quantification of aflatoxin.
The quantity of research in global aflatoxin has substantially increased over the past two decades. The evaluation of the historical status and development trend in aflatoxin scientific research can guide future research, and ultimately provide the basis for improving management procedures for governmental decisions, healthcare, industries, and educational institutions.
KeywordsAflatoxin Scopus Bibliometric VOSviewer
Journal Citation Reports
National Institutes of Health
Source Normalized Impact per Paper
Web of Science
Aflatoxins are toxic secondary metabolites, affected by fungal species, of Aspergillus molds that are largely distributed in nature and have contaminated the food supplies of animals and humans, resulting in serious health hazards and even death [1, 2]. Additional health impacts of aflatoxins include hepatotoxicity, teratogenicity, genotoxicity, and cytotoxicity . It has been estimated about 5 billion people globally are particularly affected by exposed to dietary aflatoxins . Tropical and subtropical areas of the world are the highest areas for aflatoxin contamination of the food products, where food storage conditions for cereals (e.g. maize and peanuts), spices, and milk are suboptimal [4, 5, 6].
Bibliometrics and evaluation of research performance have been carried out on a wide range of health topics [7, 8, 9, 10, 11, 12, 13, 14, 15], and several have been carried out in the fields of environmental studies [16, 17], and toxicology [18, 19, 20, 21, 22, 23, 24]. Yet, to the best of my knowledge, only a few bibliometric studies in food contamination have been done recently [25, 26, 27, 28], and only one bibliometric study explicitly focused on aflatoxin has been published by using Web of Science (WoS) database for data collection . Because the aflatoxin bibliometric study  found that aflatoxin research is now being given increased scientific attention internationally, it is therefore necessary to thoroughly evaluate and classify the existing literature from different aspects, including the countries/region of origin, journals, authors, institutes, citations, and content analysis to discover any hot and emerging topics using a large and comprehensive database. Therefore, the aim of this study is to evaluate the global scientific output of research of aflatoxin by using bibliometric techniques, and flag areas of concern.
Identifying the most productive and influential research, can be useful to anyone involved on the field of aflatoxin. Drawing on these insights may aid understanding of historical progress in aflatoxin research over the last 20 years and offer guidance researchers, and policy makers, regarding best scientific and publishing practices for future health research of this scientific field.
In this bibliometric study, we selected documents related to aflatoxin indexed in Scopus database from 1998 to 2017. This database is the large one, when compared with PubMed or Web of Science, and usually respected as a reliable source for academic and bibliometric studies [29, 30]. The use of Scopus as a bibliometric tool was based on the idea that it has a better coverage of journals than other databases such as Web of Science [29, 30]. Additionally, Scopus has been used and validated in previously published bibliometric analyses [8, 9, 18, 31, 32, 33, 34, 35, 36, 37]. Data were collected in March 2019.
The following search string was used to identify publications in the field of aflatoxin based on their titles and/or abstract: TITLE-ABS (aflatox*) AND PUBYEAR >1997 AND PUBYEAR <2018. To get greater accuracy in the findings, the search strategy for the terms related to aflatoxin was limited to Title/Abstract only because if expanded to other search fields such Keywords, many publications identified were not related to aflatoxin (i.e false-positive data). Researchers’ experience [7, 35, 38, 39] is that inclusion of search items in the title/abstract instead of a topic search (title, abstract, and keywords greatly increases specificity with minimum loss of sensitivity. The major reason for the generation of false-positive results by keyword search is that Scopus considers Keywords as author and indexed keywords such as “EMTRE drug terms”, “EMTREE medical terms”, and “Medline keywords”.
The evaluation of the collected sample involved weighing the following indictors: (1) publication output by years, (2) top 10 countries with their h-index and collaboration pattern, (3) top 10 most influential journals with their Source Normalized Impact per Paper (SNIP), and impact factors (IF), (4) top 10 most influential institutions, and (5) top 20 cited publications.
The bibliometric analysis of the international collaborative network and hot research topics were generated by VOSviewer© software version 1.6.10 . This freely available computer program (www.vosviewer.com) that is used for constructing and viewing bibliometric maps to analyze the output of countries, and authors in this sphere, and it highlights commonly used terms in the titles and abstracts for the retrieved publications, revealing those hot research topics.
Results and discussion
Top 10 most productive countries for aflatoxin research
Number of publications (%)
No of collaboration countries
No of documents from collaboration
Among the top 10 countries, five (i.e. India, Iran, Brazil, Turkey, and Egypt) were developing countries as defined by the United Nations, which suggests that each perceive this issue as a serious problem. Among this grouping, there was international diversity not associated with the traditional researching nations’ scientific productivity ranking [18, 34, 35, 36, 54, 55, 56]. The current data verified that Turkey, Egypt and Iran have been the main research contributors from the Middle Eastern countries. Consecutive outbreaks of acute aflatoxicosis in developing countries [4, 6, 57] (specifically, Turkey [58, 59], Iran , India [61, 62, 63, 64], Brazil [51, 65], and Egypt ) caused exceptionally large morbidity and mortality connected with such outbreaks [1, 67, 68, 69], and this may explain why more research has emphasized on aflatoxin since that time .
Most influential journals publishing aflatoxin research
Number of publications (%)
Food and Chemical Toxicology
Food Additives and Contaminants: Part A
International Journal of Food Microbiology
Journal of Agricultural and Food Chemistry
World Mycotoxin Journal
Journal of Food Protection
Food Additives and Contaminantsd
Top-cited papers in the Journal from 1998 through 2017 according to the number of citations in Scopus
Hussein and Brasel 
“Toxicity, metabolism, and impact of mycotoxins on humans and animals”
Williams et al. 
“Human aflatoxicosis in developing countries: A review” of toxicology, exposure, potential health consequences, and interventions”
American Journal of Clinical Nutrition
Bosch et al. 
“Epidemiology of primary liver cancer”
Seminars in Liver Disease
Machida et al. 
“Genome sequencing and analysis of Aspergillus oryzae”
“Update of survey, regulation and toxic effects of mycotoxins in Europe”
Bosch et al. 
“Epidemiology of hepatocellular carcinoma”
Clinics in Liver Disease
Placinta et al. 
“A review of worldwide contamination of cereal grains and animal feed with Fusarium mycotoxins”
Animal Feed Science and Technology
Lunn et al. 
“XRCC1 polymorphisms: effects on aflatoxin B1-DNA adducts and glycophorin A variant frequency”
Journal of Hepatology
Whittaker et al. 
“The role of signaling pathways in the development and treatment of hepatocellular carcinoma”
“Hepatocellular carcinoma: An epidemiologic view”
Journal of Clinical Gastroenterology
“Some major mycotoxins and their mycotoxicoses-An overview”
International Journal of Food Microbiology
Yu et al. 
“Clustered Pathway Genes in Aflatoxin Biosynthesis”
Applied and Environmental Microbiology
Turner et al. 
“Analytical methods for determination of mycotoxins: A review”
Analytica Chimica Acta
D’Mello et al. 
“Fusarium mycotoxins: A review of global implications for animal health, welfare and productivity”
Animal Feed Science and Technology
“The natural history of chronic hepatitis B virus infection”
Peraica et al. 
“Toxic effects of mycotoxins in humans”
Bulletin of the World Health Organization
Gomaa et al. 
“Hepatocellular carcinoma: Epidemiology, risk factors and pathogenesis”
World Journal of Gastroenterology
Key et al. 
“Diet, nutrition and the prevention of cancer”
Public Health Nutrition
Geiser et al. 
“Cryptic speciation and recombination in the aflatoxin-producing fungus Aspergillus flavus”
Proceedings of the National Academy of Sciences of the United States of America
Cluster 1 (in red color): this cluster mainly includes the terms related to the topic of detection and quantification of aflatoxin, such as “sample”, “detection”, “solution”; “validation”, “antibody”, “quantification”, “immune sensor”, and “column”.
Cluster 2 (in blue color): this cluster mainly includes the terms related to the topic of sources and biosynthesis of aflatoxin, such as “Aspergillus flavus”, “A. flavus”, “spore”, harvest”, “fungus”, “mycotoxin contamination”, and “biosynthesis”.
Cluster 3 (in yellow color): this cluster mainly includes the terms related to the topic of health effects by aflatoxin, such as “hepatocellular carcinoma”, “disease”, “effect”, “gene”, and “biomarker”.
Cluster 4 (in green color): this cluster mainly includes the terms related to the topic of detoxification and care regarding aflatoxin, such as “treatment”, “administration”, “diet”, glutathione” and “induction”.
The color of terms was coded by VOSviewer, based on the average time they appeared in the 9845 related publications (Fig. 4b). The blue color indicates the keyword appeared early and red indicates the keywords appeared later. Before 2010, namely in the early stage of research, most aflatoxins’ studies focused on terms related to the topics of “sources and biosynthesis of aflatoxin”, “health effects by aflatoxin”, and “detoxification and treatment of aflatoxin”. The latest trends showed that the terms related to the topic of detection and quantification of aflatoxin would be of concern widely in the future.
One clear theme to emerge from the findings is that the most top-cited aflatoxin publications emphasised the diversity of sub-topics similar to the research hotspots from co-occurring terms including “health effects by aflatoxin” [5, 71, 72, 75, 77, 78, 80, 84, 85, 86, 87], “sources and biosynthesis of aflatoxin” [76, 81, 82, 89], “detoxification and treatment of aflatoxin” [74, 79, 88], and “detection and quantification of aflatoxin” [73, 83].
The performance of the top 10 most productive institutions in aflatoxin research
Number of publications (%)
USDA Agricultural Research Service, Washington DC, USA
United States Department of Agriculture, USA
USDA ARS Southern Regional Research Center, USA
North Carolina State University, USA
Universidad Nacional de Rio Cuarto, Argentina
Universidade de Sao Paulo – USP, Brazil
Texas A and M University, USA
Chinese Academy of Agricultural Sciences, China
National Research Centre, Egypt
Johns Hopkins Bloomberg School of Public Health, USA
This study utilizes a bibliometric approach to analyze the current status and trend of development of aflatoxin research. But there were a few limitations within which are similar to previous studies. First, the current study was limited by the use of the search term “aflatoxin” in title and/or abstract search only. Particularly, any publications that used “aflatoxin” as a keyword or inside of the publication may have been missed in this analysis. However, if such false-negative results did exist, they will have little effect on the overall findings [7, 35, 38, 39]. Second, it surveyed just the publications in the Scopus database. Although Scopus is the most frequently used and trusted search engine, a few outlier publications might not have been included. Despite that, the current bibliometric study characterises the first concise analysis of the global publications related to aflatoxin by using Scopus and VOSviewer© and illustrates the benefits of bibliometric analysis for assessing research productivity in the field of aflatoxin in a standardised way. Third, the standardization of author names, and terms were completed based on findings on the VOSviewer© and may not be accurate because in certain cases, some authors might have different name spelling or more than one name. This might generate inaccurate research output for these authors. Despite these limitations, this study provides a relatively solid global view on aflatoxin research from these recent two decades.
The main purpose of this study was to present an overview on the past, present and future scientific research directions of the research field of aflatoxin by combining a bibliometric analysis with a literature review. The quantity of global research output on aflatoxin has substantially increased over the past 20 years, accounting for more than 9800 publications on relevant journals. In earlier years, researchers focused on terms related to the topics of “sources and biosynthesis of aflatoxin”, “health effects by aflatoxin”, and “detoxification and treatment of aflatoxin”. In recent years, researchers paying more attention to the topic of detection and quantification of aflatoxin would be concerned widely with the future. The USA was the largest contributor to aflatoxin scientific research and had the leading position in global research in this field, followed by China. Quite different from other research domains, some developing economies such as India, Iran, Brazil, Turkey, and Egypt were also among the largest contributors. This bibliometric analysis should be of interest to all governmental decisions, healthcare, industries, and educational institutions, involved in the ongoing advances in aflatoxin biosynthesis, better allocation of monitoring efforts, and improved management procedures.
The author thanks retired British Library curator Andy Simons for English editing of the manuscript. Also, the author would like to thank An-Najah National University for all administrative support throughout the implementation of this project.
SZ conceptualised the study and formulated the study design, collected the data, analysed the data, interpreted the results, and drafted the manuscript. The author read and approved the final manuscript.
No funding was received for writing this study.
Ethics approval and consent to participate
Consent for publication
The author declares that he has no competing interests.
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