Air-fry vs Normal fry

HK BioTek Interns

Many people love having fried food with strong aroma and crispy texture as snack or while watching movies. For example, fried chicken with beer or burger with French fries would always be the best combination. Recently, air frying is very popular which is claimed to be healthier and more convenient than traditional deep-oil frying and so, air fryer becomes one of the must-haves essentials for households.

Indeed, air frying is healthier than oil frying as it requires much less oil. Using air fryer, only a tablespoon of oil is needed, and it mainly relies on the hot air circulating inside to grill and fry the food to create that crispy surface by browning reaction while the juiciness and moisture inside the food can be retained. With less oil used in frying, the food is of course with less fats and so the calorie intake. However, there are also health concerns using air fryer. Usually, people would use air fryer to fry meat or potato which would produce some potentially carcinogenic substances such as heterocyclic aromatic amines from frying meat, acrylamide from frying starch-rich food like potato, even though air-frying can lower down the acrylamide content due to the lower rate of browning reaction compared to deep-frying.

In order to reduce the exposure to heterocyclic aromatic amines in diet, prolonged heating at high temperature more than 120 ℃ should be avoided and it is better to cook in medium with high water content. Besides, pretreating the meat with polyphenol rich seasoning can also help reduce the formation of heterocyclic amines, including rosemary, thyme and garlic. Eating together with vegetables can also bind to such substance, thereby reducing absorption. To reduce the exposure to acrylamide, apart from reducing the cooking time and temperature, potatoes can be blanched before frying and those with low sugar and asparagine (a kind of amino acids) contents can be selected.

In the long term, frying is never a healthy cooking method. Not only the carcinogenic problem, but heating food at such a high temperature would also destroy the nutrients inside, in particular the water-soluble vitamins and other antioxidants in vegetables when frying.

Reference

1. Fennema, O. R. (2008). Food Chemistry. 4th Edition.

2. Liao, M., Zou, B., Chen, J., Yao, Z., Huang, L., Luo, Z., & Wang, Z. (2019). Effect of domestic cooking methods on the anthocyanins and antioxidant activity of deeply purple-fleshed sweetpotato GZ9. Heliyon, 5(4), e01515. https://doi.org/10.1016/j.heliyon.2019.e01515

3. Sansano, M., Juan-Borrás, M., Escriche, I., Andrés, A., & Heredia, A. (2015). Effect of pretreatments and air-frying, a novel technology, on acrylamide generation in fried potatoes. Journal of food science, 80(5), T1120–T1128. https://doi.org/10.1111/1750-3841.12843

4. Semla, M., Goc, Z., Martiniaková, M., Omelka, R., & Formicki, G. (2017). Acrylamide: a common food toxin related to physiological functions and health. Physiological research, 66(2), 205–217. https://doi.org/10.33549/physiolres.933381

5. Sugimura, T., Wakabayashi, K., Nakagama, H., & Nagao, M. (2004). Heterocyclic amines: Mutagens/carcinogens produced during cooking of meat and fish. Cancer science, 95(4), 290–299. https://doi.org/10.1111/j.1349-7006.2004.tb03205.x