Volatile compounds in heated oleic acid‐esterified propoxylated glycerol

AbstractStatic headspace and capillary gas chromatography, in combination with infrared and mass spectrometry, were used to collect, separate, identify, and quantitate the oxidative and thermal decomposition products in two heated model compound triacylglycerols, oleic acid‐esterified propoxylated glycerol (EPG‐08 oleate) and triolein. The EPG‐08 oleate and triolein were each heated in a deep‐fat fryer at 192±8°C for 12 h each day until the oil contained ≥20% polymeric material. Most of the volatile compounds identified in heated triolein and EPG‐08 oleate were associated with the oxidative and thermal decomposition of oleates, such as short‐chain alkanes, aldehydes, and alcohols. The major volatile compounds (concentration >20 ppm) in heated EPG‐08 oleate and triolein were heptane, octane, heptanal, octanal, trans‐2‐decenal, nonanal, and trans‐2‐undecenal. However, a few minor volatile compounds, not previously found in heated fats and oils, were identified in the heated EPG‐08 oleate samples. These compounds included 1,2‐propanediol, 1‐hydroxy‐2‐propanone (hydroxyacetone), 1‐acetoxy‐2‐propanone (acetoxyacetone), 2‐ethyl‐4‐methyl‐1,3‐dioxolane, 2,2,4‐trimethyl‐1,3‐dioxolane, 2‐heptyl‐4‐methyl‐1,3‐dioxolane, and 4‐methyl‐2‐octyl‐1,3‐dioxolane. Alkyl‐substituted dioxolanes have been found in heated methyl linoleate.