Determination of strawberry volatiles with low resolution gas phase FT-IR analyser

A low-resolution gas phase Fourier transform infrared (FT-IR) analyser, designed for industrial and environmental applications, was applied to the analysis of volatile compounds of strawberry. The frozen fruit was thawed, mashed and transferred into a glass bottle mounted to a sampling system. Volatile compounds were collected by gently heating in a vacuum and then removed into the sample cell of the gas analyser at atmospheric pressure. The quantitative analysis of 14 compounds in all was performed by a built-in microcomputer applying multicomponent analysis. GC-MS applying dynamic headspace sampling was used as a reference method. A spectral library consisting of 24 typical aroma volatiles of strawberry was created before the analyses. The highest proportions were measured for acetone and 2,5-dimethyl-4-hydroxy-3(2H)-furanone. The average coefficient of variation (CV) of the relative amount of all the compounds was 35%, that of acetone being the lowest, 3.3%. Significant differences between strawberry varieties were noticed.