GC/MS and sensory analysis of volatiles from three cultivars of Capsicum

Abstract

Volatiles from three cultivars of Capsicum annuum—Jalapeño, Anaheim and Fresno—were analyzed by GC (gas chromatography) and by an experienced panel of judges. The Jalapeño volatiles were further measured by MS (mass spectroscopy) and by sniffing of the GC eluate. Agitation of the chopped, fresh fruit by swirling of the container increased nasal irritation, which interfered with descriptive analysis of the aroma. Without agitation, varietal differences were more apparent. Discriminating terms included ‘rose’ for Jalapeño > Fresno > Anaheim, ‘grassy’ for Anaheim > Fresno and Jalapeño and ‘garbanzo beans’ for Anaheim > Fresno and Jalapeño. All varieties possessed aromas described as green, green-vegetable, floral and apple. GC and GC/MS analyses indicated the presence of esters, alcohols, ketones and pyrazines which have been described previously as having green, fruity and floral aromas. Several monoterpenes and sesquiterpenes were tentatively identified. ‘Green-like’ terms were used almost exclusively when sniffing of the GC eluates from Jalapeño. ‘Green pepper’ frequently was used to describe volatiles in the retention index range where the 2-alkyl-3-methoxypyrazines would be expected to elute. Absence of floral- or apple-like aromas, similar to those perceived in the fresh fruit, may have been due to separation of compounds which interact to create these qualities, or to changes attributable to the extraction procedures.