You’ve probably heard that air fryers are this magical appliance that can fry foods without the calories. Is this method of cooking actually healthier than traditional deep frying? If you want the short answer, skip to the end.
Air fryers heat and crisp food by rapidly circulating hot air around the food. This bath of hot air replaces oil that is traditionally used. An over consumption of oil can manifest symptoms such as high blood pressure and cholesterol, and can lead to obesity, cancer, heart disease, type 2 diabetes. Dr. Arafat M. Shaker conducted a study published in Journal of Food and Nutrition Sciences regarding the health and oil consumption of french fries made traditionally versus in an air fryer.
Dr. Shaker started his experiment by cutting potatoes into equal sizes for both experiments. He fried the first batch in a traditional oil fryer at 180° c (356° f) for 40 min (6 minutes a batch). The second batch was prepped in a Tefal Actifry air fryer at 180° c for 40 mins. For every 200 g (which is about .44 lbs) of potato, traditional frying took 2 kg of oil, while air frying took 6 g- less than a tablespoon. He proceeded to measure the moisture/oil content, physico-chemical changes, and quality/taste.
His results are the average of eight trials combined. Moisture content (or dryness) can affect the quality of taste. The original potatoes contained about 77.25% moisture prior to any kind of frying. After traditional frying, moisture content was 30.51% and air frying at 35.25%. He also measured the oil absorption; traditionally fried, of course, took in more oil at 14.81% than the air fried at .0025%.
Dr. Shaker used sunflower oil as his substance for frying. There are many published studies that indicate sunflower oil is dangerous to use for frying. However, many users may not know that there are two commonly produced sunflower oils: one that is linoleic and high oleic. Based on National Sunflower Association, linoleic sunflower oil has a low heating point because it has large amounts of polyunsaturated fats- Fats that contain two or more double bonds in their chemical structure. These double bonds react with oxygen and can produce harmful compounds when exposed to high heat. Free radicals from the oil form when fatty acids reacted with oxygen. Products include aldehydes, ketones, acids, esters, and polymerized fat. These products, especially aldehydes, have been linked to severe illnesses like heart disease and cancer. The high oleic type is produced with more monounsaturated fats, and is more suitable for frying. Monounsaturated fatty oils are more stable when reacting with heat, and so they don’t release harmful byproducts at higher temperatures. If necessary, fry with monounsaturated fats like canola or peanut oil. PSA: be careful with what you fry.
Finally, Dr. Shaker also tested the organoleptic attributes (senses like taste, sight, smell etc.). Dr. Shaker assembled a panelist of 20 persons who were trained to evaluate the fries on a 10 point scale. Each sample was presented with three digit-codes, and were scored for taste, texture, appearance, crispiness, color, odor, and overall acceptability. The compiled scores show that panelists enjoyed both frying methods, though the traditionally prepared samples were noted to be harder and oilier.
The short answer: Too much oil is bad. Air frying uses little to no oil, thus is a healthier method.
Check out the published study here: http://article.sciencepublishinggroup.com/pdf/10.11648.j.jfns.20140204.26.pdf