Impact of Microwave Irradiation on Food Composition
The use of high-frequency radio waves to heat and cook food dates back to the 1920s and the invention of vacuum tube radio transmitters. Microwaves (MW) fall between radio frequencies and infrared (IR) radiation frequencies in the electromagnetic spectrum and range between 0.3 GHz and 300 GHz with wavelengths ranging between 1 m and 1 cm. MW is an innocuous radiation type, when used with standard oven protection, and exert low vibrational energy that does not interact at atomic or molecular levels. In the early 1930s, the American magazine for radio experimenters published a popular editorial entitled “Cooking by ultrashort waves”. This new and faster way of cooking was a great invention, which heated food without direct contact with hot surfaces, but only via irradiation across the path of the radio transmitter’s power. In the late 1930s, two leading American companies; Westinghouse and Bell Laboratories, released several patent applications demonstrating the efficient cooking of foods by dielectric heating at ca. 60 MHz. The food industry rapidly recognized the huge potential that MW showed as a food processing technique, while physicists and engineers developed different versions of magnetrons that were used in military defense as radars. One of those researchers was Percy L. Spencer who, inspired by a serendipitous finding, attempted to heat all types of food with his device, leading to his company, Raytheon, filing the first patent to describe MW oven prototype a few years later (1945). Only at the end of the 1960s, domestic ovens became available for American families at an affordable price (less than 500 USD). Industrial applications of MW technology for food processing and drying have grown steadily since then and the frequencies of 2.45 GHz and 915 MHz became more common. Dielectric heating has several advantages over conventional heating methods, especially with regards to energy efficiency. The peculiar type of volumetric heating that it provides dramatically reduces the temperature gradient between the outside and inside of food.
- Chemat, F., & Cravotto, G. (2011). Combined methods of assisted extraction. In N. Lebovka, E. Vorobiev, & F. Chemat (Eds.), Enhancing extraction processes in the food industry (pp. 173–193). Taylor & Francis/CRC Press, Boca Raton, Florida, US.Google Scholar
- Choi, Y.-S., Hwang, K.-E., Jeong, T.-J., Kim, Y.-B., Jeon, K.-H., Kim, E.-M., … Kim, C.-J. (2016). Comparative study on the effects of boiling, steaming, grilling, microwaving and superheated steaming on quality characteristicsof marinated chicken steak. Korean Journal for Food Science of Animal Resources, 36(1), 1–7.PubMedPubMedCentralCrossRefGoogle Scholar
- Dolinsky, M., Agostinho, C., Ribeiro, D., Rocha, G. D. S., Barroso, S. G., Ferreira, D., … Fialho, E. (2016). Effect of different cooking methods on the polyphenol concentration and antioxidant capacity of selected vegetables. Journal of Culinary Science & Technology, 14(1), 1–12.CrossRefGoogle Scholar
- Gensback, H. (1933). Cooking by ultra short waves. Short Wave Craft-the Radio Experimenter’s Magazine, 394–429.Google Scholar
- Gil-Chávez, G. J., Villa, J. A., Ayala-Zavala, J. F., Heredia, J. B., Sepulveda, D., Yahia, E. M., & González-Aguilar, G. A. (2013). Technologies for extraction and production of bioactive compounds to be used as nutraceuticals and food ingredients: An overview. Comprehensive Reviews in Food Science and Food Safety, 12(1), 5–23.CrossRefGoogle Scholar
- Mullin, J. (1994). MW processing. In G. W. Gould (Ed.), New methods of food preservation (pp. 112–134). Springer New York City, US.Google Scholar