Pesticide Residues in Nigerian Cowpea (Vigna unguiculata): Implications for Food Safety and Export Compliance

Authors

  • Henry Ifeanyi Okoro Kyungpook National University
  • Byung Wook Yun Kyungpook National University
  • Vincent Isegbe
  • Hwa-Seok Hwang Kyungpook National University
  • Ogah Bliss Idoko College of Science and Technology University of Tsukuba

DOI:

https://doi.org/10.47941/jfs.3232

Keywords:

Pesticide Residues, Cowpea (Vigna unguiculata), Maximum Residue Limits (MRLs), Export Compliance

Abstract

Purpose: This study investigates pesticide residues in cowpea (Vigna unguiculata) from key producing states across Nigeria, with the aim of enhancing phytosanitary capacity, ensuring consumer safety, and supporting compliance with export regulations.

Methodology: Dried cowpea samples were collected from major markets and production areas in six Nigerian states and the Federal Capital Territory. Residue analysis was carried out using Gas Chromatography–Tandem Mass Spectrometry (GC-MS/MS) to quantify levels of five commonly used pesticides: cypermethrin, dichlorvos, dimethoate, trichlorfon, and chlorpyrifos.

Findings: All pesticide residues detected were below the European Union Maximum Residue Limits (MRLs). These results reflect compliance with international food safety standards and suggest that pest management practices in the surveyed regions were effective.

Unique Contribution to Theory, Policy and Practice: The study demonstrates the value of systematic pesticide residue monitoring as a tool for evidence-based phytosanitary policy. It emphasizes the urgent need for expanded nationwide residue surveillance and proposes the development of a centralized Cowpea Database integrating production, residue, and trade data. Such an approach would strengthen Nigeria’s export credibility, improve consumer protection, and provide a model for residue governance in other staple crops.

Downloads

Download data is not yet available.

Author Biographies

Henry Ifeanyi Okoro, Kyungpook National University

Department of Food Security and Agricultural Development

Nigeria Agricultural Quarantine Service

Byung Wook Yun, Kyungpook National University

Department of Applied Biosciences, College of Agriculture and Life Sciences

Vincent Isegbe

Nigeria Agricultural Quarantine Service

Hwa-Seok Hwang, Kyungpook National University

Institute of International Research and Development

Ogah Bliss Idoko, College of Science and Technology University of Tsukuba

Department of Life and Earth Science

References

Akinyemi, F. A., Sunday, D. M., & Toba, A. S. (2024). Occurrence and Health Risk Assessment of Organochlorine Residues in Cowpea Grains Marketed in Abuja, Nigeria. Pesticide Science and Pest Control, 3(1). https://doi.org/10.58489/2833-0943/023

Alder, L., Greulich, K., Kempe, G., & Vieth, B. (2006). Residue analysis of 500 high priority pesticides: better by GC-MS or LC-MS/MS? Mass Spectrometry Reviews, 25(6), 838–865. https://doi.org/10.1002/MAS.20091

Anastassiades, M., Lehotay, S. J., Štajnbaher, D., & Schenck, F. J. (2003). Fast and easy multi-residue method employing acetonitrile extraction/partitioning and “dispersive solid-phase extraction” for the determination of pesticide residues in produce. Journal of AOAC International, 86(2), 412–431. https://doi.org/10.1093/jaoac/86.2.412

AOAC Official Method 2007.01 Pesticide Residues in Foods by Acetonitrile Extraction and Partitioning with Magnesium Sulfate Gas Chromatography/Mass Spectrometry and Liquid Chromatography/Tandem Mass Spectrometry First Action 2007. (n.d.).

Boukar, O., Fatokun, C. A., Huynh, B. L., Roberts, P. A., & Close, T. J. (2016). Genomic tools in cowpea breeding programs: Status and perspectives. In Frontiers in Plant Science (Vol. 7, Issue JUNE2016). Frontiers Media S.A. https://doi.org/10.3389/fpls.2016.00757

Bruzzoniti, M. C., Checchini, L., De Carlo, R. M., Orlandini, S., Rivoira, L., Massimo, &, & Bubba, D. (n.d.). QuEChERS sample preparation for the determination of pesticides and other organic residues in environmental matrices: a critical review. https://doi.org/10.1007/s00216-014-7798-4

Clarke, E., & Sarpong, D. (2013). Human health risks from pesticide residues in cowpea and maize consumed in Ejura, Ghana. International Journal of Food Contamination, 1(3), 1–9. https://pubmed.ncbi.nlm.nih.gov/23557726/

Codex Alimentarius Commission (2019). General standard for contaminants and toxins in food and feed (CODEX STAN 193-1995). Rome: FAO/WHO.

COMMISSION IMPLEMENTING REGULATION (EU) 2015/ 943 - of 18 June 2015 - on emergency measures suspending imports of dried beans from Nigeria and amending Annex I to Regulation (EC) No 669/ 2009. (n.d.).

EFSA (2020). The 2018 European Union report on pesticide residues in food. EFSA Journal, 18(4), e06057. https://doi.org/10.2903/j.efsa.2020.6057

European Commission (2005). Regulation (EC) No 396/2005 of the European Parliament and of the Council on maximum residue levels of pesticides in or on food and feed of plant and animal origin. Official Journal of the European Union, L 70, 1–16.

European Commission. (2023). TRACES – Trade Control and Expert System. Retrieved from the European Commission’s official Food Safety portal

Fagbohun A, Dauda M.S., and Anjorin T.S. (2024), Occurrence and Health Risk Assessment of Organochlorine Residues in Cowpea Grains Marketed in Abuja, Nigeria. Pesticide Science and Pest Control. 3(1). DOI: 10.58489/2833-0943/023

FAO, Rome & ICRISAT, Addis Ababa. 2020. World Food and Agriculture – FAO Statistical Yearbook 2020 176 pp. Rome

FAO. (2022). FAOSTAT statistical database. Food and Agriculture Organization of the United Nations. http://www.fao.org/faostat

FAO/WHO (2013). Principles and methods for the risk assessment of chemicals in food. Environmental Health Criteria 240. Geneva: WHO

Ferrer, C., Lozano, A., Agüera, A., Girón, A. J., & Fernández-Alba, A. R. (2011). Overcoming matrix effects using the dilution approach in multiresidue methods for fruits and vegetables. Journal of Chromatography A, 1218(42), 7634–7639. https://doi.org/10.1016/j.chroma.2011.07.033

Field, A. (n.d.). Discovering Statistics Using IBM SPSS Statistics.

Frontiers Agronomy. (2023). Cowpea (Vigna unguiculata): Challenges and opportunities for sustainable production in Sub-Saharan Africa. Frontiers in Agronomy, 5, 1220387. https://www.frontiersin.org/journals/agronomy/articles/10.3389/fagro.2023.1220387/full

Hung, C. C., Sari Simaremare, S. R., Hsieh, C. J., & Yiin, L. M. (2019). Simultaneous determination of pyrethroid, organophosphate and carbamate metabolites in human urine by Gas Chromatography-Mass Spectrometry (GCMS). Applied Sciences (Switzerland), 9(5). https://doi.org/10.3390/app9050879

Kumperščak, S., Medved, M., Terglav, M., Wrzalik, A., & Obrecht, M. (2019). Traceability Systems and Technologies for Better Food Supply Chain Management. Quality Production Improvement - QPI, 1(1), 567–574. https://doi.org/10.2478/cqpi-2019-0076

Langyintuo, A. S., Lowenberg-DeBoer, J., Faye, M., Lambert, D., Ibro, G., Moussa, B., Kergna, A., Kushwaha, S., Musa, S., & Ntoukam, G. (2003). Cowpea supply and demand in West and Central Africa. In Field Crops Research (Vol. 82, Issues 2–3, pp. 215–231). Elsevier. https://doi.org/10.1016/S0378-4290(03)00039-X

Lehotay, S. J., Son, K. A., Kwon, H., Koesukwiwat, U., Fu, W., Mastovska, K., Hoh, E., & Leepipatpiboon, N. (2010). Comparison of QuEChERS sample preparation methods for the analysis of pesticide residues in fruits and vegetables. Journal of Chromatography A, 1217(16), 2548–2560. https://doi.org/10.1016/j.chroma.2010.01.044

Leskovac, A., & Petrović, S. (2023). Pesticide Use and Degradation Strategies: Food Safety, Challenges and Perspectives. In Foods (Vol. 12, Issue 14). Multidisciplinary Digital Publishing Institute (MDPI). https://doi.org/10.3390/foods12142709

Macrothink Institute. (2021). Assessment of pesticide residues in cowpea grains from selected markets in Ibadan, Nigeria. Journal of Agricultural Studies, 9(4), 134–148. https://www.macrothink.org/journal/index.php/jas/article/view/19228

Maštovská, K., & Lehotay, S. J. (2004). Evaluation of common organic solvents for gas chromatographic analysis and stability of multiclass pesticide residues. Journal of Chromatography A, 1040(2), 259–272. https://doi.org/10.1016/j.chroma.2004.04.017

Medires Online. (2021). Occurrence and health risk assessment of organochlorine residues in cowpea grains marketed in Abuja, Nigeria. Medires Journal of Food Safety, 3(2), 55–66. https://mediresonline.org/article/occurrence-and-health-risk-assessment-of-organochlorine-residues-in-cowpea-grains-marketed-in-abuja-nigeria

Michela Salvatore, M., El-Sheikh, E.-S. A., & H Prodhan, M. D. (2023). Editorial: Monitoring and risk assessment of pesticide residues and mycotoxins - A potential public health concern. https://doi.org/10.3390/molecules272

Nigerian Agricultural Quarantine Service (NAQS). (2022). EU ban: NAQS discloses effort to make Nigerian beans acceptable internationally. https://naqs.gov.ng/eu-ban-naqs-discloses-effort-to-make-nigerian-beans-acceptable-internationally/

Omoigui, L. O., Kamara, A. Y., Batieno, J., Iorlamen, T., Kouyate, Z., Yirzagla, J., Diallo, S., & Garba, U. (n.d.). Transforming African Agriculture Guide to in West Africa Cowpea Production.

Oshatunberu, M. A., Oladimeji, A., Henry, S. O., Olaniyan, O. A., & Raimi, M. O. (2023). Concentrations of Pesticides Residues in Grain Sold at Selected Markets of Southwest Nigeria. Sustainability in Environment, 8(4), p1. https://doi.org/10.22158/se.v8n4p1

Pallant, J. (2020). SPSS Survival Manual. https://doi.org/10.4324/9781003117452

Patricia Okafor, K., Emmanuel Akunne, C., Ebele Okeke, T., UzonnaOnonye, B., Kingsley Asogwa, K., AlvanChidi, C., SylviaOlisa, C., Eucharia Ekwuonu, N., Ijeoma Azaka, E., & Kingsley Mbelede, C. (n.d.). IJO-International Journal of Applied Science Pesticide Residues in Cowpea (VignaunguiculataL.Walp) grains sold in Senatorial Zones of Anambra State, Nigeria Pesticide Residues in Cowpea (VignaunguiculataL.Walp) grains sold in Senatorial Zones of Anambra State, Nigeria Pesticide Residues in Cowpea (VignaunguiculataL.Walp) grains sold in Senatorial Zones of Anambra State, Nigeria. https://ijojournals.com/index.php/as/index

Pesticide residues in food-2002 Report of the Joint Meeting of the FAO Panel of Experts on Pesticide Residues in Food and the Environment and the WHO Core Assessment Group on Pesticide Residues. (n.d.).

Pihlström, T., Fernández-Alba, A. R., Ferrer Amate, C., Erecius Poulsen, M., Lippold, R., Carrasco Cabrera, L., Pelosi, P., Valverde, A., Unterluggauer, H., Mol, H., Jezussek, M., Malato, O., Štěpán, R., & Lambert, M. (n.d.). Analytical Quality Control and Method Validation Procedures for Pesticide Residues Analysis In Food and Feed Sante 11312/2021 v2.

Regulation - 396/2005 - EN - EUR-Lex. (n.d.). Retrieved September 1, 2025, from https://eur-lex.europa.eu/eli/reg/2005/396/oj/eng

Schenck, F. J., & Hobbs, J. E. (2004). Evaluation of the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) Approach to Pesticide Residue Analysis Environmental Contamination and Toxicology 24. Bull. Environ. Contam. Toxicol, 73, 24–30. https://doi.org/10.1007/s00128-004-0388-y

Sodedji, F. A. K., Agbahoungba, S., Nguetta, S. P. A., Agoyi, E. E., Ayenan, M. A. T., Sossou, S. H., Mamadou, C., Assogbadjo, A. E., & Kone, D. (2020). Resistance to legume pod borer (Maruca vitrata Fabricius) in cowpea: genetic advances, challenges, and future prospects. In Journal of Crop Improvement (Vol. 34, Issue 2, pp. 238–267). Taylor and Francis Inc. https://doi.org/10.1080/15427528.2019.1680471

Subedi, D., Paudel, M., Poudel, S., & Koirala, N. (2025). Food Safety in Developing Countries: Common Foodborne and Waterborne Illnesses, Regulations, Organizational Structure, and Challenges of Food Safety in the Context of Nepal. In Food Frontiers (Vol. 6, Issue 1, pp. 86–123). John Wiley and Sons Inc. https://doi.org/10.1002/fft2.517

Tamò, M., Srinivasan, R., Dannon, E., Agboton, C., Datinon, B., Dabiré, C., Baoua, I., Ba, M., Haruna, B., & Pittendrigh, B. (n.d.). Biological control: a major component for the long-term cowpea pest management strategy.

The 2015 European Union report on pesticide residues in food. (2017). EFSA Journal, 15(4). https://doi.org/10.2903/j.efsa.2017.4791

Timko, M. P., & Singh, B. B. (2008). Cowpea, a Multifunctional Legume. In Genomics of Tropical Crop Plants (pp. 227–258). Springer New York. https://doi.org/10.1007/978-0-387-71219-2_10

Wikipedia. (2023a). Agriculture in Nigeria. https://en.wikipedia.org/wiki/Agriculture_in_Nigeria

Wikipedia. (2023b). Cowpea. https://en.wikipedia.org/wiki/Cowpea

Wilkowska, A., & Biziuk, M. (2011). Determination of pesticide residues in food matrices using the QuEChERS methodology. In Food Chemistry (Vol. 125, Issue 3, pp. 803–812). Elsevier Ltd. https://doi.org/10.1016/j.foodchem.2010.09.094

World Food and Agriculture – Statistical Yearbook 2022. (2022). In World Food and Agriculture – Statistical Yearbook 2022. FAO. https://doi.org/10.4060/cc2211en

Downloads

Published

2025-10-05

How to Cite

Okoro, H. I., Yun, B. W., Isegbe, V., Hwang, H.-S., & Idoko, O. B. (2025). Pesticide Residues in Nigerian Cowpea (Vigna unguiculata): Implications for Food Safety and Export Compliance. Journal of Food Sciences, 7(1), 71–89. https://doi.org/10.47941/jfs.3232

Issue

Section

Articles