Simple Concentration and Analysis of Cabbage Spoilage Odor –Use of Sorptive Media Mono Trap

Importance of the Topic

The monitoring of volatile compounds generated during cabbage spoilage is essential for food safety, quality control and shelf-life assessment. Identifying odor-active molecules helps processors and researchers understand decay pathways, develop packaging strategies and design early warning systems for microbial contamination and loss of product quality.

Objectives and Study Overview

This study employed a simple sorptive sampling device, MonoTrap RGC18TD, combined with thermal desorption–GC-MS and olfactometry to screen and characterize volatile profiles from cabbage undergoing controlled spoilage. Sensory evaluation was performed in parallel to correlate chemical changes with perceived odors at different decay stages.

Methodology and Instrumentation

Sample Preparation and Pretreatment:

• Place 25 g of cabbage (or chicken for comparison) into 100 mL headspace vials.
• Incubate at 60 °C for defined periods (immediately after cutting, 3 days and 7 days) to induce spoilage.
• Collect headspace volatiles at room temperature for 3 hours using MonoTrap RGC18TD cartridges.

Analytical System:

• Thermal desorption–GC–MS with split outlet enabling simultaneous olfactometry (GC/O) and mass spectrometry detection (scan range m/z 28.5–600).
• Column: InertCap Pure-WAX, 0.25 mm i.d. × 60 m, 0.25 µm film.
• Oven program: 40 °C hold for 5 min, ramp at 6 °C/min to 250 °C.
• Carrier gas: Helium, constant flow 1 mL/min.
• Desorption: 200 °C for 5 min, splitless, cryo-trapping at –150 °C.
• Sniffing device: OP275 sniffing pot for odor detection.

Key Instrumentation Section:

• MonoTrap RGC18TD sorptive media.
• TD–GC–MS with thermal desorption unit.
• InertCap Pure-WAX capillary column.
• GC/Olfactometry interface and sniffing pot OP275.

Main Results and Discussion

Temporal Changes in Volatile Profile:
The headspace chromatograms showed a progressive increase in peak intensities with extended spoilage, illustrating the accumulation of decomposition products.

Identified Major Odor-Active Compounds After 7 Days at 60 °C:

• Dimethyl disulfide: rotten egg odor (sulfurous marker).
• Hexanal: green, grassy note (lipid oxidation).
• 2-Heptanone: sweet, floral nuance.
• 2-Methyl-1-butanol and 3-Methyl-1-butanol: raw garbage, bitter undertones.
• 1-Pentanol: green leaf attribute.
• Hexanenitrile: bitter, sharp aroma (nitrogenous origin).
• 3-Hydroxy-2-butanone: buttery tone.
• Dimethyl trisulfide: putrid odor (advanced sulfur breakdown).
• 1-Hexanol: pungent grassy smell.
• Acetic acid: sour, acidic character.
• 1-Octen-3-ol: mushroom-like alcohol note.
• Hexane, 1-nitro-: metallic impression (nitrogenous volatile).
• Benzaldehyde: almond-like fragrance.
• 4-Hexen-1-ol: green fatty aroma.
• Benzonitrile: bitter, lingering tone.
• S-Methyl methanethiosulfonate: putrid, sulfurous marker.
• 2,6,6-Trimethyl-2-hydroxycyclohexylidene-acetic acid lactone: lactonic, fruity nuance.
• Indole: fecal, heavy odor (advanced decay).

Discussion Points:

• Graphite carbon in the MonoTrap enhances retention of sulfur and nitrogen compounds, improving detection of key spoilage markers.
• Split flow arrangement reduces sensitivity by one order of magnitude but allows concurrent olfactometry for direct odor correlation.
• Library matching without standards provides qualitative identification; stronger odors highlighted by olfactometric intensity.

Benefits and Practical Applications of the Method

• Enables rapid screening of spoilage volatiles without complex sample preparation.
• Combines chemical and sensory data to pinpoint impactful odorants.
• Sorbent-based trapping is versatile for diverse food matrices.
• Useful in quality control, shelf-life studies and detection of off-flavor compounds in agrifood and processing environments.

Future Trends and Possibilities

Integration with high-resolution MS and two-dimensional GC could offer more precise compound identification and quantitation. Automated data processing and machine learning models may predict spoilage stages and correlate volatile patterns with microbial activity. Miniaturized, portable thermal desorption units could enable in-field monitoring for fresh produce and processing lines.

Conclusion

This work demonstrates a straightforward sorptive headspace sampling approach using MonoTrap RGC18TD coupled with TD–GC–MS/Olfactometry to profile cabbage spoilage volatiles. Key sulfur, nitrogen and oxygenated compounds responsible for off-odors were identified, supporting applications in food quality monitoring and odor research.

Reference

GL Sciences Inc. Technical Note GT070: Simple Concentration and Analysis of Cabbage Spoilage Using MonoTrap RGC18TD.