Aerosol emissions and their volatility from heating different cooking oils at multiple temperatures

Abstract

Heating cooking oils at high temperatures emits aerosols in the fine and ultrafine size ranges as well as a variety of volatile organic compounds. Exposure to these emissions has been associated with various respiratory and cardiovascular ailments. In this study, we characterized aerosol emissions from various popular frying oils using an electric heat source at multiple temperatures (below and above their individual smoke points). At 180 °C, a common deep-frying temperature, oils with lower smoke points (olive oil and lard) generated the highest aerosol mass concentrations among all oils tested. The volatility characteristics of these oil-generated aerosols were also studied by analyzing their volume distributions after thermal conditioning through a thermodenuder. For most of the oils, thermal conditioning beyond temperatures of 75 °C resulted in the near complete removal of volatiles leaving behind non-volatile cores in the 60-100 nm range. Fourier Transform-Ion Cyclotron Mass Spectrometry analyses of sample extracts obtained from smoking different oils exhibited large chemical similarity with average molecular mass in the range of 620-640 atomic mass units and low oxygen-to-carbon ratios (∼0.16). Lastly, we estimated the respiratory deposition values of different oils for a 30 minute exposure period, and the results show that lard had the highest average particle mass deposition in all three regions of the respiratory system (1-10 μg), whereas peanut oil had the lowest average values (∼1 μg).