Characteristic Evaluation for Volatile Components of Soluble Coffee Depending on Freeze-Drying Conditions

Abstract

Volatile aroma compounds of freeze-dried soluble coffee were investigated to evaluate the effects of freeze-drying temperature conditions on their intensities and aroma characteristics by employing both GC/MS and charm-analysis, which is a GC/Olfactometry (GC/O) method. The coffee solutions with 40% solid content were freeze-dried changing freezing and drying temperatures. According to the results, it was demonstrated that the compounds identified based on human olfactory sense were different from those detected by GC/MS, and that the GC/O analysis method enabled evaluation of the characteristics and intensity of each compound as well as aroma profiles under various freezing and drying temperatures. Subsequently, GC/O method was found to be effective to detect and identify the volatile compounds giving the aroma peculiar to freeze-dried coffee, and useful to obtain the fundamental information for designing the optimal aroma characteristics of final product to conform the consumer preference based on the characteristic changes in aroma affected by freeze-drying conditions.