Lipid changes in egg yolks and cakes baked in microwave ovens
Elizabeth A. Schiller, Dan E. Pratt · 1973
Early research found microwave cooking may chemically alter fats and lipids in food beyond simple heating effects.
Plain English Summary
This 1973 study examined how microwave oven cooking changes the fatty acid composition and lipid structure in egg yolks and baked goods. The research investigated whether microwave radiation alters the nutritional and chemical properties of lipids during food preparation, focusing on molecular changes that occur during microwave heating.
Why This Matters
This early research represents one of the first scientific investigations into how microwave radiation affects food at the molecular level. While microwave ovens operate at 2.45 GHz and are designed to heat food through water molecule agitation, this study suggests the effects may extend beyond simple heating to actual structural changes in nutrients. The focus on lipids is particularly significant because these molecules are essential for cell membrane function and hormone production. What makes this research especially relevant today is that it predates the widespread adoption of microwave cooking. In 1973, microwave ovens were just entering American homes, yet researchers were already questioning whether this technology might alter food in ways beyond conventional heating. The science demonstrates that electromagnetic fields can indeed cause molecular changes in biological materials, and food represents our most direct daily exposure to microwave-processed substances.
Exposure Information
Specific exposure levels were not quantified in this study. Duration: 2.75 min. at 2.45 GHz, 13.0 min. at 915 MHz, and 22 min. at 190°C
Study Details
To study the effects of microwave heating on lipid changes in egg yolks and cakes, specifically examining oxidation and hydrolysis of fatty acids.
Egg yolks were cooked to a final temperature of approximately 100°C by three methods: in a conventio...
There were no significantly different changes in the fatty acid composition of yolk or yolk plus add...
The findings that lipid changes are minor in products subjected to microwave radiation are in accordance with the recent review by Rosen. Rosen pointed out that microwave energy is too low to cause chemical changes due to direct interaction with molecules and chemical bonds, and chemical changes have not been confirmed in studies carried out properly controlled conditions. Thermal effects are sufficient to explain most if not all reactions of microwaves, even on living cells. Over-spark formation, and x-ray contamination are reportedly sources of error that must be considered as causes of chemical changes observed by workers with microwave energy.
Show BibTeX
@article{lipid_changes_in_egg_yolks_and_cakes_baked_in_microwave_ovens_g6883,
author = {Elizabeth A. Schiller and Dan E. Pratt},
title = {Lipid changes in egg yolks and cakes baked in microwave ovens},
year = {1973},
}