Air fryers have rapidly become a staple in European kitchens, valued for their energy efficiency and convenience. New scientific findings indicate they may also offer benefits for indoor air quality, provided one key condition is met.
Research on cooking emissions and indoor air quality
Researchers from the University of Birmingham examined the pollutants released during cooking using air fryers, focusing on volatile organic compounds and other airborne particles.
Using custom-built air quality chambers, the team measured emissions produced while cooking frozen fried foods, fresh low-fat foods and fresh high-fat foods. Volatile organic compounds, or VOCs, are carbon-based chemicals commonly released from sources such as paints, cleaning products and certain cooking processes, and are often found at higher concentrations indoors.
How the study was conducted
The researchers used a commercially available 4.7-litre air fryer and compared emissions across different types of food. The study was published in the American Chemical Society journal ES&T Air and is among the first to examine the range of pollutants emitted by air fryers.
Frozen onion rings, smoked bacon and unsmoked bacon were found to produce the highest levels of cooking-related emissions, which researchers attribute to their high fat content.
However, the study found that cooking high-fat foods in a deep-fat fryer produces VOC levels between 10 and 100 times higher than those generated by air frying.
Key findings on reduced emissions
Lead author Christian Pfrang, Professor of Atmospheric Science, said the findings build on earlier research that examined only lean foods.
“This study is the latest that shows the potential benefits for indoor air quality of using air fryers for cooking,” he said. “We wanted to look at a greater range of foodstuffs, including those with higher fat content, to see how they compare when cooked in an air fryer.”
Importance of cleaning and maintenance
The research also highlighted the role of cleanliness in maintaining lower emissions. Food residue left inside air fryers can increase the release of harmful particles into the air.
Even after cleaning, tests showed that air fryers emitted VOCs and ultra-fine particles during empty tray tests designed to measure residual emissions. Air fryers that had been used more than 70 times produced 23 percent more cooking-related VOCs and more than twice the number of ultra-fine particles compared with new appliances.
Researchers attributed this to the build-up of grease and residues on internal surfaces that are difficult to access during routine cleaning.
Design implications for air fryers
Professor Pfrang noted that repeated use without the ability to thoroughly clean inaccessible surfaces can reduce some of the indoor air quality benefits associated with air fryers.
While the emission levels observed are not considered a cause for concern for households, the findings support the case for air fryer designs that allow for deeper and more effective cleaning to keep emissions low over time.
Source: ES&T Air, University of Birmingham, euronews