Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 7/30/2003
Publication Date: 9/5/2003
Citation: Rengarajan, R., Seitz, L.M. 2003. Analysis of flavor compounds from microwave popcorn using supercritical fluid co2 followed by dynamic/static headspace techniques. In: Handbook of Flavor Characterization: Sensory, Chemical and Physiological Techniques. K. Deibler and J. Delwiche (eds.). Marcel Dekker, Inc. Chapter 22. Book Chapter. Interpretive Summary: Because flavor is an important aspect of popcorn quality, there is a need to know what volatile compounds contribute to the flavor. Only a few published reports were available concerning determinations of volatile compounds from popcorn. Most previous methods for isolating and identifying popcorn volatiles utilized either laborious solvent extraction or insensitive static headspace techniques. We used a relatively fast and convenient dynamic headspace purge (DHP) analysis to determine volatile compounds from freshly popped commercial flavored and non-flavored microwave popcorn. The obtained results were compared with supercritical fluid (SF) extraction followed by DHP. Results showed that the sensitivity of the latter method, in general, was several fold higher than DHP itself. Many previously reported potent-aroma compounds were found by both methods in this study, not only with very little sample quantity, but also with relatively little sample preparation time In a separate experiment, we showed that a solid-phase-micro-extraction (SPME) technique could be used effectively by exposing a SPME fiber to the SF extract from popcorn and then desorbing volatiles from the fiber in the inlet of the gas chromatograph. This SPME method showed highest sensitivity towards pyrazines, which includes many important flavor compounds found in popcorn. However, some compounds were detected best by directly injecting the SF extract into the gas chromatograph.
Technical Abstract: Dynamic headspace purge (DHP) analysis was used to observe volatile compounds from freshly popped commercial flavored and non-flavored microwave popcorn. The obtained results were compared with supercritical fluid extraction (SFE) followed by DHP. Results showed that the sensitivity of the latter method (SFE-DHP), in general, was several fold higher than DHP itself. Previously reported potent-aroma compounds like 2-acetyl-tetrahydropyridine, 4-vinylguaiacol, 2-phenylacetaldehyde and 2-acetyl-1-pyrroline were found by both methods in this study, not only with very little sample quantity but also with relatively little sample preparation time. Except for 2-methyl pyrazine, all observed pyrazines were 2-6 fold higher with the SFE-DHP than the DHP method. In a separate experiment, the supercritical fluid (SF) extract from popcorn was a) exposed to a SPME fiber (SFE-SPME), and b) injected directly into the gas chromatograph. SFE-SPME showed highest sensitivity towards pyrazines. FuraneolTM, vanillin, sulfurol, maltoxaine, and delta-dodecalactone were detected best by the SFE-Direct injection method.