Air fryer, to buy or not to buy: discover here the biggest pros & cons
For a few years now, just about everywhere in the world, air fryers have become a must have, a culinary icon to own.
They promise delicious fried food, just like “the original”, requiring very little oil (up to 80% less) (1).
What’s more, they are compact, they don’t cost much, they reduce the time for preparing meals, becoming the ideal alternative for small families who have little time to spend at the stove.
With Christmas just around the corner, you may be considering buying one; so it’s a good idea to find out how they work; how they can fry without using oil (or rather, very little); whether air fryers are bad for you; or if they are really as healthy as they advertise.
What happens during frying
As always, I like to start from the ABC, as I prefer you to reach the correct conclusions; but if you want to go directly to my personal verdict on the air fryer, you can go directly to the end of the article by clicking here.
Classic frying is done in the following way: when you immerse the food in boiling oil, the temperature of its surface immediately increases (from about 20°C to 170°C in a few seconds). This sudden change causes an immediate evaporation of the water contained on the surface of the food, with the consequent formation of the crust, which, besides delighting the palate, creates an impassable barrier, or if you prefer a seal.
Sealing prevents the passage of water naturally present inside the food, and the very high temperature outside the crust, from penetrating inside.
So there you have it, in broad strokes, the magic of frying: juicy food inside and crispy food outside (it has to be said that we humans have some twisted tastes!).
Home frying is normally done in two ways:
– conventional; foods are fried with little oil inside a pan; temperatures range roughly from 160 to 190°C;
– by immersion or deep frying; foods are fried in pots with high sides or in deep fryers, by immersing them in boiling oil; temperatures range roughly from 170-190° C.
Through oil frying, physical and chemical transformations take place, ranging from oxidation to hydrolysis, from polymerization to gelatinization of starch, or denaturation of proteins. All this gives the final product very pleasant characteristics to the palate and to the eye; at the same time, however, there are reactions which are not exactly in line with human health.
The immersion method, by reducing the contact surface of the food with oxygen and cold air, ensures a faster cooking time, a longer life to the frying oil (less oxygen = less oxidation); immersion fried foods absorb less fats and lose less nutrients.
In summary “it is better” than frying in a pan, but always relatively speaking; so much so that both methods are frowned upon by doctors and nutritionists, mainly for 2 reasons:
– they still cause a high introduction of fat, that is, extra calories: in the case of fries, you go from the normal 0 fat present in the potato, up to 30 grams of fat per 100 grams of product;
– the fats and oils used for frying develop polar compounds, which can be harmful to health; therefore their quantity is regulated by specific provisions: the oils used for frying must be replaced once the limit of deterioration, expressed as content of polar compounds, of 25 g/100 g is reached. The measurement is carried out by means of probes, or visually as in the home: an oil darker and denser certainly must be disposed of.
How does the air fryer work?
An air fryer is a kind of miniature oven: it distributes hot air by convection, with the help of a fan.
The principles are the same as traditional frying, but the frying fluid is modified: hot air replaces oil!
In the small cooking chamber, the food, after being lightly oiled, is placed on top of a basket; this facilitates the passage of hot air, uniformly over the entire surface of the food to be cooked. In this way it is possible to obtain a final product very satisfactory and very similar to the traditional fried food.
The features to look for in an air fryer
The material of construction is preferable to be stainless steel: for better hygiene and not to have to deal with plastic, when the working temperatures can reach easily 200 ° C. In the case, of course, the plastics used must not contain BPA (Bisphenol A), especially if you have small children; also non-stick coatings such as for the basket, must be free of PFOA (perfluorooctanoic acid), like the pans and pots we use normally.
Immediately a first anticipation: this technique offers you a food with the characteristics of the classic and tasty fried, crispy outside and juicy inside, almost without oil.
Without a doubt then the air fryer is definitely better than the classic oil fryers, but this does not mean it is a healthy way to cook food: the final product is always a fried food or better to say a food cooked in a dry environment at high temperatures.
Health related considerations
– A concrete help for those who don’t want to get fat while continuing to eat fried foods.
– However, a healthy diet does not only mean less calories; in fact, it is good to prepare food with methods that damage as little as possible the nutrients present, and possibly without causing the production of toxic substances.
Therefore we are far from the healthiness of steam cooking, pressure cooking, a quick stir-fry or blanching in little water.
In this perspective we can consider air frying as the lesser evil to fry food, obtaining “less unhealthy fried foods”, thanks to the possibility of fat reduction, degradation and oxidation of lipids; not healthier foods!
– The way I see it, we should be careful of the paradox effect; that is, by following positive advertising messages such as “light”, “oil-free”, or “the choice of the health-conscious”, the naive consumer may abuse it, turning it into the “worst method of frying”.
The desire to “make up” for all the previous renunciations can become widespread; so much so that I know of people who use their air fryer more than 6 times a week!
– A habit that in the long run could turn out to be harmful: nutrients decrease because of the longer time (almost double) compared to classic methods; adding to the other problems typical of frying in general.
When frying, short-chain fatty acids, aldehydes, ketones, alcohols and non-volatile products, recognized as polar compounds, are generated (2).
– Another risk associated with fried foods is acrylamide.
What is acrylamide
During the frying of potato chips (i.e. any cooking method that takes place above 120°C), among other transformations, acrylamide is generated; a substance defined as neurotoxic, genotoxic, carcinogenic, and mutagenic, i.e. able to cause mutations in our DNA, thus increasing the risk of cancer (3, 4, 5, 6); as well as a series of serious disorders and dysfunctions in vital and/or reproductive systems.
But high temperature alone is not sufficient for its formation; it requires the presence of the amino acid asparagine, together with some sugars such as glucose and fructose. The reaction, although still not completely understood, is believed to be related to the Maillard reaction, that is the non-enzymatic formation of that brown color we like so much.
The major food sources of acrylamide, besides potato chips, are starchy foods such as crackers, bread, cookies and breakfast cereals; but also coffee and chocolate
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– If you are a fan of French fries and want to buy an air fryer just to eat them guilt-free, you should reconsider this intention. The air fryer allows to reduce up to 90% of the amount of acrylamide in food(7,8); however the food cooked in this way is not completely free of it: a consumer study in Hong Kong of 02.2021, found that some samples obtained from air fryers of different brands, contained concentrations above the threshold recommended by European guidelines (500 micrograms per kg), in one case even 13 times higher, 7.038 mcg per kg.
– To worsen the situation in foods cooked at high temperatures in general, we must consider also other molecules, always carcinogenic, such as heterocyclic amines and polycyclic aromatic hydrocarbons; some of these names I had treated in the article entitled the risks related to barbecue.
– Then we have AGEs (Advanced Glycation End products in food); they are pathogenic compounds capable of causing the induction and progression of many chronic diseases.
Foods normally contain AGEs even when they are raw; however, there are several scientific evidences(9, 10, 11) that correlate cooking methods based on high temperature and low humidity, with the constant and significant formation of AGEs in foods.
This is a complex subject that deserves more than a few lines, so I will postpone the in-depth study to a future article; for the moment it is enough to know that it is mostly foods rich in proteins (red meat, processed meats, cheese etc) that cause the formation of AGEs, while fruits and vegetables in general contain significantly lower levels, even after grilled or fried.
From an organoleptic point of view
– Marketing slogans point to messages such as “Perfect fries, with very little oil”.
Indeed the hot air fryer produces fried foods with little oil; but “true connoisseurs” such as chefs and grandmothers, disagree on the word ‘perfect’!
From a scientific point of view, some researchers have analyzed the samples with scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The result is that the two products (obtained by air frying and by conventional frying) are different both for the crust, for the humidity and also for the thickness 12: during immersion frying, the gelatinization of the starch is higher; this results in a visibly drier and thicker crust, therefore higher moisture inside the food, thus making it more juicy and pleasant.
– Now, I do not have a laboratory at home and I am not a picky eater, so I’ll give my honest opinion: although not perfect, the result of air frying is still very convincing; of course it does not work very well with foods with high density of liquids such as batters, while it gives its best with solid foods, better if thawed.
From a practical point of view
– Compared to traditional frying, the convenience is really remarkable: it is enough to brush the food with oil and place it in the basket previously sprayed or brushed with oil as well.
– Washing the basket and other parts of the appliance is usually practical and easy; but there is plenty of complaint about a less than adequate cleanliness.
– And watch out for the instructions! Using too much oil can be just as counterproductive as not putting any at all; or using the appliance already dirty with food would give you back a terrible “headache”.
From an energy consumption point of view
– An air fryer is compact, has an energy consumption equal to a water kettle, (about 1500 W: values range from 1000 to 2300 W depending on the model and size).
– Compared to a normal oven, it cooks much faster, almost in half the time, thanks to its compactness.
– However, it is neither a microwave nor a conventional fryer, which is why it takes about 10-12 minutes to fry chips: twice the time required for normal frying.
– It follows that if you have a large family (more than 4 people) given the various rounds of cooking required, you will be better off turning on the oven, which equipped with a thermostat, eventually consumes about 25% of the total time of activation.
From an ethical point of view
– Using less oil is good for the environment; moreover, domestic oil is often not disposed of properly, causing pollution of seas and waterways.
– Saving energy is also good for the planet (as long as we are talking about a small family, better if 1-2 people), considering that our electricity is almost always obtained from non-renewable sources.
– In a logic of degrowth, we should not waste precious resources of the planet with the purchase of unuseful objects (we should buy things only if we really need them); as explained above, frying often, even with little oil, does not offer you a healthy method; therefore if you have to underuse it for your health, why should buy it?
Other considerations and conclusions
– The air fryer will not stink up your kitchen like a friggitoria (Italian fast food shops, where you can buy only fried foods), as it normally happens with conventional frying.
– Your kitchen will not become incandescent, which is common when using a regular oven. So also in hot summer days you can cook.
– But there is another aspect that is close to my heart: it could entice “healthy food haters” to enjoy a nice plate of brussels sprouts, or Portuguese style fried green beans, or lentil burgers and why not tofu sticks… instead of food with the worst quality and full of empty calories.
In conclusion and to be more clear, if you are thinking of buying this machine ONLY to fry chips, pork ribs or chicken wings, my answer is, “You will never get my approval!”
Good revolution to you all
1)Zaghi, Aline Nalon, et al. “Frying process: From conventional to air frying technology.” Food Reviews International 35.8 (2019): 763-777.
2) Xu XQ, Tran VH, Palmer M, White K, Salisbury P. Chemical and physical analyses and sensory evaluation of six deep-frying oils. J. Am. Oil Chem. Soc. 1999;76:1091–9.
3) Hogervorst, J. G. F.; van den Brandt, P. A.; Godschalk, R. W. L.; van Schooten, F. J.; Schouten, L. J. Interaction between Dietary Acrylamide Intake and Genetic Variants for Estrogen Receptor-Positive Breast Cancer Risk. Eur. J. Nutr. 2018. DOI: 10.1007/s00394-018-1619-z
4) Capuano, E.; Fogliano, V. Acrylamide and 5-Hydroxymethylfurfural (HMF): A Review on Metabolism, Toxicity, Occurrence in Food and Mitigation Strategies. LWT- Food Sci. Technol. 2011, 44(4), 793–810. DOI: 10.1016/j.lwt.2010.11.002
5) Semla, M.; Goc, Z.; Martiniaková, M.; Omelka, R.; Formicki, G. Acrylamide: A Common Food Toxin Related to Physiological Functions and Health. Physiol. Res. 2016, 66(2), 205–217.
6) Liu, Z.; Tse, L. A.; Ho, S. C.; Wu, S.; Chen, B.; Chan, D.; Wong, S. Y. Dietary Acrylamide Exposure Was Associated with Increased Cancer Mortality in Chinese Elderly Men and Women: A 11-Year Prospective Study of Mr. And Ms. OS Hong Kong. J. Cancer Res. Clin. Oncol. 2017, 143(11), 2317–2326.
7) Sansano, M et al. “Effect of pretreatments and air-frying, a novel technology, on acrylamide generation in fried potatoes.” Journal of food science vol. 80,5 (2015): T1120-8. Doi:10.1111/1750-3841.12843
8) Haddarah, Amira, et al. “The effect of borage, ginger and fennel extracts on acrylamide formation in French fries in deep and electric air frying.” Food Chemistry 350 (2021): 129060.
9) Advanced glycoxidation end products in commonly consumed foods. Goldberg T, Cai W, Peppa M, Dardaine V, Baliga BS, Uribarri J, Vlassara H J Am Diet Assoc. 2004 Aug; 104(8):1287-91.
10) Wheeler ML, Daly A, Evert A, Franz MJ, Geil P, Holzmeister LA, Kulkarni K, Loghmani E, Ross TA, Woolf P. Choose Your Foods: Exchange Lists for Diabetes, Sixth Edition, 2008: Description and guidelines for use. J Am Diet Assoc. 2008;108:883–888.
11) Uribarri, Jaime et al. “Advanced glycation end products in foods and a practical guide to their reduction in the diet.” Journal of the American Dietetic Association vol. 110,6 (2010): 911-16.e12. doi:10.1016/j.jada.2010.03.018
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