Comparative analysis of thermal processing on aroma-active compounds of egg curd

Egg curd is a favorite snack in China. For a better understanding of aroma formation, the changes of volatile compounds during thermal process were analyzed by headspace solid-phase microextraction and gas chromatography-olfactometry-mass spectrometry. After thermal coagulation, the total concentration of odorants increased by 17 times, in which aldehyde compounds were the most preponderant. Based on aroma extract dilution analysis, eight predominant aroma compounds were identified, most of which were the products of the lipid oxidation and enhanced with the increase of coagulation temperature. After sterilization, total concentration of odorants increased by 7.96-folds. 13 new odorants generated, seven of them were heterocyclic compounds, which accounted for 78.6% of total volatiles. About 12 aroma-active compounds were identified as predominant compounds, which were most likely to be generated in Maillard reaction. Hence, most of the key odorants of sterilized egg curd increased with the elevated temperature. Practical applications This research revealed different aroma characters in different thermal processing methods, which would help to better understand and control the critical quality-determining parameters for egg curd processing.