Many health-conscious people choose diets rich in fruits, vegetables, and lean proteins, believing these foods are among the safest options. However, even nutritious foods can contain hidden contaminants that form during cooking or food processing. Among the compounds receiving increasing scientific attention are polycyclic aromatic hydrocarbons (PAHs).
PAHs are produced when foods are exposed to high temperatures or smoke, including during grilling, roasting, smoking, and frying. Some PAHs are classified as known or probable carcinogens. They can also enter the food supply through environmental contamination, making accurate detection an important part of food safety monitoring.
Why PAHs Matter
According to the National Cancer Institute, PAHs are generated when fat and meat juices drip onto hot surfaces or open flames during cooking. The resulting smoke contains PAHs that can settle onto the food. Similar compounds may also form during smoking or heavy charring of foods, particularly meats and certain edible oils.
Studies in animals have shown that PAHs and other compounds produced during high-temperature cooking can cause cancer. However, large human studies have not yet established a clear relationship between dietary PAH exposure from cooked meat and cancer risk. Because of this uncertainty, accurately measuring human exposure remains an important part of ongoing research.
Traditional Testing Methods Have Limitations
Detecting PAHs in food is technically challenging. Conventional laboratory methods, including solid-phase extraction, liquid-liquid extraction, and accelerated solvent extraction, can produce reliable results but require multiple preparation steps, large volumes of organic solvents, and considerable laboratory time.
These procedures can become impractical when laboratories must analyze hundreds of food samples from different product categories. As a result, researchers have sought faster and more efficient methods that maintain high analytical accuracy while reducing costs and chemical use.
QuEChERS Provides a Faster Solution
To address these challenges, scientists have increasingly adopted a method known as QuEChERS, an acronym for Quick, Easy, Cheap, Effective, Rugged, and Safe. Originally developed for pesticide residue testing, the technique has since been adapted to detect numerous food contaminants, including PAHs.
A 2025 study published in Food Science and Biotechnology by researchers from the Department of Food Science and Biotechnology at Seoul National University of Science and Technology, led by Professor Joon Goo Lee, applied QuEChERS to measure eight priority PAHs in food. The researchers aimed to improve analytical speed while reducing solvent consumption and maintaining high recovery rates.
How the Method Performed
The researchers extracted PAHs from food samples using acetonitrile before comparing several purification strategies involving different sorbent materials. These clean-up procedures remove substances that could interfere with instrumental analysis and were evaluated across multiple food types to ensure reliable performance.
The analytical method demonstrated excellent linearity, with calibration curves for all eight PAHs showing R² values greater than 0.99. Detection limits ranged from 0.006 to 0.035 µg/kg, while quantification limits ranged from 0.019 to 0.133 µg/kg, allowing the detection of extremely low concentrations.
Recovery rates, which measure how efficiently compounds are extracted and detected, ranged from 86.3% to 109.6% at 5 µg/kg, from 87.7% to 100.1% at 10 µg/kg, and from 89.6% to 102.9% at 20 µg/kg. Precision values remained between 0.4% and 6.9% across different food matrices, demonstrating consistent analytical performance.
Among the foods analyzed, soybean oil contained the highest PAH concentrations, followed by duck meat and canola oil. According to Professor Lee, the QuEChERS approach simplifies laboratory analysis while maintaining high efficiency across a wide variety of food products.
Applications Continue to Expand
Following the Seoul National University of Science and Technology study, several research groups have further refined QuEChERS-based PAH testing. A separate 2025 study published in Foods introduced a modified QuEChERS protocol incorporating an additional freeze-out step and applied the method to 302 retail food samples collected across Asia.
That investigation reported the highest concentrations of four priority PAHs in Kezuribushi, a smoked and dried fish product. Grilled chicken feet also attracted attention when evaluated using the European Food Safety Authority’s margin of exposure approach, which compares estimated human intake with doses associated with health effects.
Another 2025 study focused on cereals and cereal-based foods using a modified QuEChERS protocol combined with Z-Sep⁺ clean-up and gas chromatography-tandem mass spectrometry. Among 96 cereal samples and 18 processed cereal products from the Romanian market, chrysene was detected in 17% of cereal samples, while no quantifiable PAHs were found in the processed products.
Together, these studies demonstrate that QuEChERS can be successfully adapted to many food categories, including edible oils, meat products, smoked fish, cereals, and processed grain products. They also highlight that PAH contamination varies considerably depending on raw materials, food processing methods, cooking practices, and environmental conditions.
Benefits for Food Safety
For food manufacturers and regulatory agencies, faster and more efficient PAH testing could significantly improve routine food safety monitoring. Reduced preparation time and lower operating costs make it more practical to screen large numbers of products throughout the food supply chain.
The technique also offers environmental and occupational advantages. Using smaller volumes of organic solvents reduces hazardous chemical waste while limiting laboratory personnel’s exposure to potentially harmful substances. These improvements support broader efforts to make analytical laboratories safer and more environmentally sustainable.
For consumers, improved testing does not mean that commonly consumed foods have suddenly become unsafe. Instead, enhanced monitoring allows contamination to be identified and controlled more effectively. The information generated through these methods may help regulators refine food safety standards, encourage manufacturers to optimize cooking and processing techniques, and support public health recommendations on grilling, smoking, and other high-temperature cooking methods.
The Researcher’s Contribution
Professor Joon Goo Lee is a food safety specialist at Seoul National University of Science and Technology whose work focuses on food regulation and risk assessment. He previously served as a scientific officer at Korea’s Ministry of Food and Drug Safety and as a visiting researcher at Food Standards Australia New Zealand.
He is a member of Korea’s National Food Sanitation Committee and serves as an expert for the FAO/WHO Joint Expert Committee on Food Additives. As executive director of several Korean food safety organizations, his research contributes to the development of evidence-based food safety policies and strategies for reducing exposure to harmful contaminants.
According to Professor Lee, analytical methods such as QuEChERS can improve consumer protection while reducing reliance on hazardous laboratory chemicals. As food production and supply chains continue to evolve, efficient contaminant monitoring will remain an important component of ensuring both the nutritional quality and safety of the global food supply.