Analysis of Volatile Flavor Components in Roasted Peanuts Using Supercritical Fluid Extraction and Gas Chromatography−Mass Spectrometry

A method for extraction and identification of volatile flavor components in roasted peanuts is described. The method is based on supercritical fluid extraction (SFE), with identification using gas chromatography−mass spectroscopy (GC−MS) in scan mode. Appropriate choice of supercritical fluid density (0.35 g/mL of CO 2 ) and extraction temperature (50 °C), at a pressure of 96 bar, results in selective extraction of compounds associated with roasted flavor rather than nonvolatile lipid material. The compounds examined in this study were hexanol, hexanal, methylpyrrole, benzene acetaldehyde, methylpyrazine, 2,6-dimethylpyrazine, ethylpyrazine, 2,3-dimethylpyrazine, 2,3,5-trimethylpyrazine, 2-furancarboxaldehyde, 2-ethyl-5-methyl- and 2-ethyl-6-methylpyrazine, and 3-ethyl-2,5-dimethylpyrazine. Careful grinding of frozen samples and alternate layering with silanized glass wool in the extraction thimble allows good recovery of the volatiles (>85%) in a single extraction step. Comparison of chromatograms for samples produced over a range of roasting conditions and sensory panel results shows that this method can be used to relate roasting conditions and consumer acceptance of roast quality.