Contaminant Detection: Tools for Ensuring Food Safety
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Ensuring the safety of food and agricultural products is essential to protect human health and maintain the economic viability of the agriculture industry and the stability of global food supply chains. It also plays a significant role in preventing foodborne diseases1. Furthermore, ensuring food safety is a key to achieving sustainable development goals, particularly in reducing hunger and improving nutrition1. For farmers and agronomists, the safety of their agricultural products is not just a priority for maintaining their business but a fundamental responsibility. Detecting contaminants in crops and livestock is crucial to ensuring consumers’ health and maintaining trust in their agricultural and food products2. Ensuring food safety is the practice of preventing food-borne diseases by applying proper food handling procedures throughout the food supply chain2. Food safety procedures involve limiting the presence of hazards, such as bacteria, toxins, or chemicals, that may harm the health of consumers. This article explores the latest tools and technologies in contaminant detection, highlighting their role in addressing challenges and advancing safety standards in the food and agriculture sector.
Types of Contaminants in Agriculture
Farmers and agronomists should understand the specific contaminants that can affect their crops and livestock. These contaminants can originate from various sources and pose significant threats to food safety and agricultural productivity3. These contaminants are classified as below:
Pesticides: Pesticides are widely used in agriculture to control pests and improve crop yields. However, the excessive or improper use of pesticides can lead to residue accumulation of these chemicals in crops, posing risks to consumers and the environment’s health3.
Heavy Metals: Heavy metals such as arsenic, cadmium, lead, chromium, copper, zinc, nickel, and mercury can contaminate soil and crops4. These metals can originate from natural geogenic sources or human activities such as industrial processes and waste disposal, as well as the agriculture resources such as the irrigation water, mineral fertilizers, organic manure, and the usage of fossil fuel5.
Pathogens: Pathogens, including bacteria, viruses, and fungi, can cause diseases in crops and livestock. These pathogens can be present in the soil, water, or air and can spread through insects, animals, or farming equipment6.
Mycotoxins: Mycotoxins are produced by the secondary metabolism of various fungi, particularly Aspergillus, Penicillium, and Fusarium species7. These fungi can contaminate crops such as grains, nuts, and fruits under certain conditions, especially when there is high humidity and improper storage. When ingested, mycotoxins can have harmful effects on humans and animals, causing health issues ranging from acute poisoning to chronic diseases8.
Recognizing these diverse sources of contamination enables farmers to implement proper detection measures, ensuring food safety and maintaining agricultural productivity.
Contaminant detection methods:
Farmers and agronomists alike can detect these risks using various methods:
Pesticides: To detect pesticides, farmers can use advanced pesticides biosensors methods such as nanomaterial-based sensing arrays and handheld sensors9. These sensors can detect levels of pesticides in the air. Another method is using a handheld device that measures the identity and quantity of pesticides on products. To test for pesticides, users simply pass a swab over the fruit or vegetable, insert the swab into the detector such as spectrometer, and wait about 30 seconds10.
Heavy Metals: Heavy metals in soil and crops can be detected using techniques like Laser-Induced Breakdown Spectroscopy (LIBS) and X-Ray Fluorescence (XRF)11. These techniques are used for detecting heavy metals in soil. Farmers and gardeners who suspect their soil may contain heavy metals can also improve their soil or use cultivation techniques that reduce the risk12.
Pathogens: Pathogens can be detected using modern diagnostic kits based on DNA and protein analysis. These kits are designed to detect plant diseases early, either by identifying the presence of the pathogen in the plant (by testing for the presence of pathogen DNA) or the molecules (proteins) produced by either the pathogen or the plant during infection13.
Mycotoxins: Farmers have various methods to detect mycotoxins in their fields. For instance, Immunochemical techniques employ antibodies and offer sensitivity and ease of use14. Additionally, chromatography methods like High Performance Liquid Chromatography (HPLC) and Gas Chromatography/Mass Spectrometry (GC/MS) enable mycotoxin detection and quantification. Spectrometric techniques like Ultraviolet (UV) and fluorescence (FL) detection, along with Mass Spectrometry (MS), provide additional options, particularly for fluorescent mycotoxins. These methods collectively equip farmers with effective tools for comprehensive mycotoxin detection and monitoring in agriculture14.
These methods help farmers and agronomists implement targeted detection measures, ensuring food safety and maintaining agricultural productivity. However, it’s important to note that these methods require specific equipment and, in some cases, specialized training as well as high investments15. Therefore, continuous education and investment in technology are crucial for effective risk detection in farming. However, these requirements can be challenging for smallholders. Hence, implementing various measures to prevent these risks is essential, such as the following:
Preventing Contamination:
To mitigate heavy metal contamination, farmers employ strategies such as maintaining a neutral soil pH above 6.5. This practice reduces the uptake of heavy metals by plants4. Additionally, adding phosphorus based on soil test results helps form insoluble compounds with lead, therefore reducing its toxicity and further minimizing the risk of heavy metal contamination. Farmers address the risk of pesticide contamination through strict adherence to requirements specified on pesticide product labels. Before application, they assess soil characteristics such as texture, slope, and organic matter to ensure proper pesticide usage and prevent contamination. Knowledge of local geology and groundwater depth is crucial for selecting appropriate pesticides and application methods. Implementing best practices during application, such as using larger droplet sizes, checking weather forecasts, and cleaning pesticide equipment away from waterways, helps reduce the likelihood of contamination16.
Finally, agricultural practices play a crucial role in preventing cross-contamination. Foremost among these practices is ensuring the quality of irrigation water since it is the primary source of microbiological and heavy metals contaminations. Additionally, ensuring the proper application of fertilizers, implementing soil testing, integrated pest management, and utilizing biopesticides are essential components in maintaining agricultural quality and safety.
References
(1) Background | Food safety and quality | Food and Agriculture Organization of the United Nations. https://www.fao.org/food-safety/background/en/ (accessed 2024-01-16).
(2) Food contaminants. https://www.iaea.org/topics/food-contaminants (accessed 2024-01-16).
(3) Sources of soil pollution and major contaminants in agricultural areas. https://doi.org/10.4060/cb4894en.
(4) Eshagberi, G. Toxic Effects of Heavy Metals on Crop Plants. 2012.
(5) Zhou, L.; Yang, B.; Xue, N.; Li, F.; Seip, H. M.; Cong, X.; Yan, Y.; Liu, B.; Han, B.; Li, H. Ecological Risks and Potential Sources of Heavy Metals in Agricultural Soils from Huanghuai Plain, China. Environ. Sci. Pollut. Res. 2014, 21 (2), 1360–1369. https://doi.org/10.1007/s11356-013-2023-0.
(6) Livestock and Poultry Infectious Diseases: Pathogenesis and Immune Mechanisms. https://www.frontiersin.org/research-topics/47450/livestock-and-poultry-infectious-diseases-pathogenesis-and-immune-mechanisms/magazine (accessed 2024-01-16).
(7) Sweeney, M. J.; Dobson, A. D. Mycotoxin Production by Aspergillus, Fusarium and Penicillium Species. Int. J. Food Microbiol. 1998, 43 (3), 141–158. https://doi.org/10.1016/s0168-1605(98)00112-3.
(8) Mycotoxins. https://www.who.int/news-room/fact-sheets/detail/mycotoxins (accessed 2024-01-16).
(9) Berkal, M. A.; Nardin, C. Pesticide Biosensors: Trends and Progresses. Anal. Bioanal. Chem. 2023, 415 (24), 5899–5924. https://doi.org/10.1007/s00216-023-04911-4.
(10) Galon, L.; Bragagnolo, L.; Korf, E. P.; dos Santos, J. B.; Barroso, G. M.; Ribeiro, V. H. V. Mobility and Environmental Monitoring of Pesticides in the Atmosphere — a Review. Environ. Sci. Pollut. Res. 2021, 28 (25), 32236–32255. https://doi.org/10.1007/s11356-021-14258-x.
(11) Yang, Z.; Ren, J.; Du, M.; Zhao, Y.; Yu, K. Enhanced Laser-Induced Breakdown Spectroscopy for Heavy Metal Detection in Agriculture: A Review. Sensors 2022, 22 (15), 5679. https://doi.org/10.3390/s22155679.
(12) Alsafran, M.; Saleem, M. H.; Al Jabri, H.; Rizwan, M.; Usman, K. Principles and Applicability of Integrated Remediation Strategies for Heavy Metal Removal/Recovery from Contaminated Environments. J. Plant Growth Regul. 2023, 42 (6), 3419–3440. https://doi.org/10.1007/s00344-022-10803-1.
(13) Yang, Y.; Saand, M. A.; Huang, L.; Abdelaal, W. B.; Zhang, J.; Wu, Y.; Li, J.; Sirohi, M. H.; Wang, F. Applications of Multi-Omics Technologies for Crop Improvement. Front. Plant Sci. 2021, 12.
(14) Mycotoxin detection and analysis methods. MycotoxinSite. https://mycotoxinsite.com/mycotoxins-detection-and-analysis-methods/?lang=en (accessed 2024-01-16).
(15) Collis, R. C., Stewart. Digital Agriculture for Small-Scale Producers: Challenges and Opportunities. https://cacm.acm.org/magazines/2021/12/256930-digital-agriculture-for-small-scale-producers/abstract (accessed 2024-01-16).
(16) Sun, S.; Sidhu, V.; Rong, Y.; Zheng, Y. Pesticide Pollution in Agricultural Soils and Sustainable Remediation Methods: A Review. Curr. Pollut. Rep. 2018, 4 (3), 240–250. https://doi.org/10.1007/s40726-018-0092-x.
Further reading
Chemical hazards in food
