Evaluation of two gas chromatography-olfactometry methods: the detection frequency and perceived intensity method

Area of Science:

• Analytical Chemistry
• Sensory Science

Background:

• Gas chromatography-olfactometry (GC-O) is crucial for identifying volatile compounds responsible for flavor.
• Evaluating different GC-O methods is essential for optimizing sensory analysis accuracy and reliability.

Purpose of the Study:

• To compare the repeatability, sensitivity range, and discrimination capabilities of two GC-O methods: detection frequency and perceived intensity.
• To assess the performance of these methods in analyzing volatile flavor compounds at varying concentrations.

Main Methods:

• Six volatile flavor compounds were analyzed at multiple concentration levels.
• A panel of eight assessors utilized both the detection frequency and perceived intensity methods.
• Statistical analysis included coefficient of variance for repeatability and correlation coefficients for concentration-response relationships.

Main Results:

• The detection frequency method demonstrated higher repeatability, with an average coefficient of variance of 16% compared to 28% for the intensity method.
• The perceived intensity method showed slightly better discrimination between concentration levels, with an average correlation coefficient of 0.93 versus 0.91 for detection frequency.
• Both methods exhibited similar ranges of sensitivity for the analyzed compounds.

Conclusions:

• The detection frequency method provides more accurate and repeatable results for volatile compound analysis.
• The perceived intensity method offers superior accuracy in discriminating between different concentration levels of flavor compounds.
• The choice of GC-O method depends on whether repeatability or concentration discrimination is the primary analytical goal.