Sniffing port analysis

Van Ruth, S.M., Roozen, J.P. (1994) Gas chromatography/sniffing port analysis and sensory evaluation of commercially dried beU peppers capsicum annuum) after rehydration. Food Chem. 51, 165-170... 

Linssen, J.P.H., J.L.G.M. Janssens, J.R Roozen, and M.A. Posthumus, 1993. Combined gas chromatography and sniffing port analysis of volatile compounds of mineral water packed in polyethylene laminated packages. Food Chem., 46 367. 

The influence of additives on odor formation in packaged food products is analyzed by a combination of sensory evaluation (sniffing port analysis) and gas chromatography. This method was successfully applied to samples containing erucamide and diatomaceous earth. 

S. M. Van Ruth, J. P. Roozen, and J. L. Cozijnsen, Gas chromatography/sniffing port analysis evaluated for aroma release from rehydrated french heans (Phaesolus vulgaris). Food Chem. 56 343 (1996). 

Sensory Validation of Sampling and GC Techniques The sensory evaluation was carried out by a panel of three judges (employees of Pebeyre Ltd.). For this study, an external odor port was attached to the gas vent (5) of the D.C.I. System and the rotary valve (4) was not switched (analysis using the Desorption - Concentration mode). Thus, after the thermal desorption of the volatiles from the trap, the rotary valve was positioned so that the unresolved aroma Isolate went to our sniffing port. The response was measured as similarity or dissimilarity to Black Truffle aroma. 

The odor is powerful, choking when undiluted, but becomes tolerable in extreme dilution, almost pleasant fruity, fermented with a peculiar note resembling that of roasted cocoa or coffee (Arctander, 1967). For Motoda (1979), it is apple or malt. Fors (1983) mentions other odor descriptions as burnt, sickly for GC eluates, musty, fruity aromatic at 100°C becoming burnt cheese at 180°C. It is described as fermented, pungent, fruity at a sniffing port in a headspace/GC analysis of freshly roasted coffee (Holscher and Steinhart, 1992a). Like C.ll, it is a key component in a brew with a high aroma impact (Pollien et al., 1998). The flavor of the (R)-isomer is chocolate-like (Chemisis, 1971). 

GC can be safely and routinely used for essential oils of known composition whose constituents already have been elucidated by hyphenated techniques like GC/MS, GC/FT-IR, NMR, and so on. The use of GC alone for the analysis of new or uncommon essential oils is recommended only for reference information leading to tentative identification of the major constituents. This information also requires support by sensory evaluation. Quantitative determination of the separated constiments must be achieved by GC. Odor evaluation of the eluted components from a GC column is possible through the introduction of a sniffing port fixed to the end of the column via an all-glass splitting device. This allows the analyst to sniff the compound eluted while it simultaneously appears as a peak on the integrator/recorder. 

Gas chromatography, (GC) sniffing, aroma extract dilution analysis (AEDA), and CHARM analysis are well accepted tools to identify the sensory properties of individual molecules in complex mixtures [9-10]. In fact, they are the fastest tool to identify typical character impact molecules and odor off-notes. They require well trained people who are able to keep pace with the fast emerging GC peaks imagine that a small gas balloon of ca. 0.1 mL leaving the sniff port within 3 sec has to be transferred to the... 

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